<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rico, L</style></author><author><style face="normal" font="default" size="100%">Ogaya, R</style></author><author><style face="normal" font="default" size="100%">Barbeta, A</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in DNA methylation fingerprint of Quercus ilex trees in response to experimental field drought simulating projected climate change</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA methylation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">methylation-sensitive amplified polymorphism</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">419-427</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rapid genetic changes in plants have been reported in response to current climate change. We assessed the capacity of trees in a natural forest to produce rapid acclimation responses based on epigenetic modifications. We analysed natural populations of Quercus ilex, the dominant tree species of Mediterranean forests, using the methylation-sensitive amplified polymorphism (MSAP) technique to assess patterns and levels of methylation in individuals from unstressed forest plots and from plots experimentally exposed to drought for 12 years at levels projected for the coming decades. The percentage of hypermethylated loci increased, and the percentage of fully methylated loci clearly decreased in plants exposed to drought. Multivariate analyses exploring the status of methylation at MSAP loci also showed clear differentiation depending on stress. The PCA scores for the MSAP profiles clearly separated the genetic from the epigenetic structure, and also significantly separated the samples within each group in response to drought. Changes in DNA methylation highlight the large capacity of plants to rapidly acclimate to changing environmental conditions, including trees with long life spans, and our results demonstrate those changes. These changes, although unable to prevent the decreased growth and higher mortality associated with this experimental drought, occurred together with a dampening in such decreases as the long-term treatment progressed.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rico, L</style></author><author><style face="normal" font="default" size="100%">Ogaya, R</style></author><author><style face="normal" font="default" size="100%">Terradas, J</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Community structures of N-2-fixing bacteria associated with the phyllosphere of a Holm oak forest and their response to drought</style></title><secondary-title><style face="normal" font="default" size="100%">PLANT BIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial TRF richness</style></keyword><keyword><style  face="normal" font="default" size="100%">diazotrophic community</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar phyllosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">t-RFLP</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">WILEY-BLACKWELL</style></publisher><pub-location><style face="normal" font="default" size="100%">111 RIVER ST, HOBOKEN 07030-5774, NJ USA</style></pub-location><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">586-593</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Biological nitrogen (N) fixation is a key pathway in terrestrial ecosystems and is therefore critical for understanding the responses of ecosystems to global environmental changes. The free-living diazotrophic community is distributed along the canopy-to-soil profile, but the ecological significance of epiphyllic N-2 fixers, despite their functional relevance, on plant foliar surfaces remains very poorly understood compared with the N-2-fixing community in forest litter and soils. We assessed the community structure of N-2 fixers and overall bacteria by genetic fingerprinting (t-RFLP) to explore the seasonal successional patterns of the microbial community in the natural phyllosphere of a Holm oak (Quercus ilex) forest submitted to 12-year field experiment of rain exclusion mimicking the conditions of drought projected for the coming decades. Leaves of Holm oak were analysed in different seasons over a period of 1.5years. The bacterial community of the phyllosphere did not correspond to the surrounding soil biome in the same area. These analyses provided field evidence for the presence of free-living diazotrophs associated with the tissues of leaves of Holm oak, the dominant tree species of many Mediterranean forests. The results also revealed that the community composition is affected seasonally and inter-annually by the environment, and that the composition shifts in response to climate change. Drought treatment increased the richness of the epiphyllic microbial community, especially during the summer. These changes were associated with higher C:N ratios of leaves observed in response to drought in semiarid areas. This epiphyllic microbiota that can potentially fix N-2 extends the capacity of plants to adapt to the environment.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rivas-Ubach, Albert</style></author><author><style face="normal" font="default" size="100%">Gargallo-Garriga, Albert</style></author><author><style face="normal" font="default" size="100%">Sardans, Jordi</style></author><author><style face="normal" font="default" size="100%">Oravec, Michal</style></author><author><style face="normal" font="default" size="100%">Mateu-Castell, Laia</style></author><author><style face="normal" font="default" size="100%">Pérez-Trujillo, Míriam</style></author><author><style face="normal" font="default" size="100%">Parella, Teodor</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Urban, Otmar</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought enhances folivory by shifting foliar metabolomes in Quercus ilex trees.</style></title><secondary-title><style face="normal" font="default" size="100%">The New phytologist</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">ecology</style></keyword><keyword><style  face="normal" font="default" size="100%">ecometabolomics</style></keyword><keyword><style  face="normal" font="default" size="100%">folivory</style></keyword><keyword><style  face="normal" font="default" size="100%">metabolomics</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">At the molecular level, folivory activity on plants has mainly been related to the foliar concentrations of nitrogen (N) and/or particular metabolites. We studied the responses of different nutrients and the whole metabolome of Quercus ilex to seasonal changes and to moderate field experimental conditions of drought, and how this drought may affect folivory activity, using stoichiometric and metabolomic techniques. Foliar potassium (K) concentrations increased in summer and consequently led to higher foliar K : phosphorus (P) and lower carbon (C) : K and N : K ratios. Foliar N : P ratios were not lowest in spring as expected by the growth rate hypothesis. Trees exposed to moderate drought presented higher concentrations of total sugars and phenolics and these trees also experienced more severe folivory attack. The foliar increases in K, sugars and antioxidant concentrations in summer, the driest Mediterranean season, indicated enhanced osmoprotection under natural drought conditions. Trees under moderate drought also presented higher concentrations of sugars and phenolics; a plant response to avoid water loss. These shifts in metabolism produced an indirect relationship between increased drought and folivory activity.</style></abstract><accession-num><style face="normal" font="default" size="100%">24443979</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Corcobado, Tamara</style></author><author><style face="normal" font="default" size="100%">Cubera, Elena</style></author><author><style face="normal" font="default" size="100%">Juárez, Enrique</style></author><author><style face="normal" font="default" size="100%">Moreno, Gerardo</style></author><author><style face="normal" font="default" size="100%">Solla, Alejandro</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought events determine performance of Quercus ilex seedlings and increase their susceptibility to Phytophthora cinnamomi</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest Meteorology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Flooding</style></keyword><keyword><style  face="normal" font="default" size="100%">Invasive pathogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Oak decline</style></keyword><keyword><style  face="normal" font="default" size="100%">Weather extremes</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><volume><style face="normal" font="default" size="100%">192-193</style></volume><pages><style face="normal" font="default" size="100%">1-8</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">More frequent weather extremes are expected to occur in the Mediterranean region within the present context of climate change. These extremes could affect forests and plant diseases driven by pathogens. It is hypothesised that simulation of weather extremes during Quercus ilex growth will influence early performance and susceptibility to the invasive oomycete Phytophthora cinnamomi. In 2010, 140 Q. ilex seedlings were subjected to three watering regimes under greenhouse conditions: waterlogging (W), water stress (S) and optimal watering regime for growth (C). During the second vegetative period, conditions were altered to create the following scenarios: WW, WS, SS, SW and CC. After the second vegetative period, plants were artificially infested with P. cinnamomi. Holm oak (Q. ilex) was more sensitive to flooding in the first year of growth than in the second year. The altered scenarios produced plants with a lower fine-to-total root ratio than plants in unaltered scenarios. Plants with the highest growth rates maintained their relatively rapid growth and photosynthetic activity under altered scenarios. However, plants with the highest growth rates became the plants with the lowest growth rates when two consecutive years of drought occurred, indicating a trade-off by Q. ilex in growth investment, observed only if the water stress scenario persists. Seedlings were more sensitive to water shortage than to waterlogging, especially if they encountered a dry scenario during the first year. Exposure to drought events increased seedling mortality rates after P. cinnamomi infection. Waterlogging combined with subsequent water deprivation was the worst scenario when soil was infested with P. cinnamomi, causing 100% mortality of plants.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author><author><style face="normal" font="default" size="100%">Barbeta, Adrià</style></author><author><style face="normal" font="default" size="100%">Asensio, Dolores</style></author><author><style face="normal" font="default" size="100%">Liu, Daijun</style></author><author><style face="normal" font="default" size="100%">Alessio, Giorgio Arturo</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Foliar CO2 in a holm oak forest subjected to 15 years of climate change simulation</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A long-term experimental drought to simulate future expected climatic conditions for Mediterranean forests, a 15% decrease in soil moisture for the following decades, was conducted in a holm oak forest since 1999. Net photosynthetic rate, stomatal conductance and leaf water potential were measured from 1999 to 2013 in Quercus ilex and Phillyrea latifolia, two co-dominant species of this forest. These measurements were performed in four plots, two of them received the drought treatment and the two other plots were control plots. The three studied variables decreased with increases in VPD and decreases in soil moisture in both species, but the decrease of leaf water potential during summer drought was larger in P. latifolia, whereas Q. ilex reached higher net photosynthetic rates and stomatal conductance values during rainy periods than P. latifolia. The drought treatment decreased ca. 8% the net photosynthetic rates during the overall studied period in both Q. ilex and P. latifolia, whereas there were just non-significant trends toward a decrease in leaf water potential and stomatal conductance induced by drought treatment. Future drier climate may lead to a decrease in the carbon balance of Mediterranean species, and some shrub species well resistant to drought could gain competitive advantage relative to Q. ilex, currently the dominant species of this forest.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lopez-Iglesias, Bárbara</style></author><author><style face="normal" font="default" size="100%">Villar, Rafael</style></author><author><style face="normal" font="default" size="100%">Poorter, Lourens</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Functional traits predict drought performance and distribution of Mediterranean woody species</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Oecologica</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Functional groups</style></keyword><keyword><style  face="normal" font="default" size="100%">functional traits</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean species</style></keyword><keyword><style  face="normal" font="default" size="100%">RGR</style></keyword><keyword><style  face="normal" font="default" size="100%">Rooting depth</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><volume><style face="normal" font="default" size="100%">56</style></volume><pages><style face="normal" font="default" size="100%">10-18</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Water availability is one of the key environmental factors that affect plant establishment and distribution. In many regions water availability will decline with climate change, exposing small seedlings to a greater likelihood of drought. In this study, 17 leaves, stem, root, and whole-plant traits of ten woody Mediterranean species were measured under favourable growing conditions and seedling drought survival was evaluated during a simulated dry-down episode. The aims of this study were: i) to assess drought survival of different species, ii) to analyse which functional traits predict drought survival time, and iii) to explain species distribution in the field, based on species drought survival and drought strategies. Drought survival time varied ten-fold across species, from 19 to 192 days. Across species, drought survival was positively related to the rooting depth per leaf area, i.e., the ability to acquire water from deeper soil layers while reducing transpiring leaf area. Drought survival time was negatively related to species ability to grow quickly, as indicated by high relative growth and net assimilation rates. Drought survival also explained species distribution in the field. It was found that species were sorted along a continuum, ranging between two contrasting species functional extremes based on functional traits and drought performance. One extreme consisted of acquisitive fast-growing deciduous species, with thin, soft metabolically active leaves, with high resource use and vulnerability to drought. The opposite extreme consisted of conservative slow-growing evergreen species with sclerophyllous leaves, deep roots, a low transpiring area, and low water use, resulting in high drought survival and drought tolerance. The results show that these drought strategies shape species distribution in this Mediterranean area.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tsonev, Tsonko</style></author><author><style face="normal" font="default" size="100%">Wahbi, Said</style></author><author><style face="normal" font="default" size="100%">Sun, Pengsen</style></author><author><style face="normal" font="default" size="100%">Sorrentino, Giuseppe</style></author><author><style face="normal" font="default" size="100%">Centritto, Mauro</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Gas Exchange, Water Relations and their Relationships with Photochemical Reflectance Index in Quercus ilex Plants during Water Stress and Recovery</style></title><secondary-title><style face="normal" font="default" size="100%">INTERNATIONAL JOURNAL OF AGRICULTURE AND BIOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CO2 transport conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf gas exchange</style></keyword><keyword><style  face="normal" font="default" size="100%">photorespiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Relative water content</style></keyword><keyword><style  face="normal" font="default" size="100%">Spectral reflectance index</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2014///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">335 - 341</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Diffusional limitations to photosynthesis (A), relative water content (RWC) and their association with photochemical reflectance index (PRI) were studied in holm oak (Quercus ilex L.) saplings subjected to water stress and subsequent water stress relief. RWC decreased sharply as drought progressed. Following rewatering, RWC gradually increased to pre-stress values. A, stomatal conductance (g(s)), mesophyll conductance (g(m)), total conductance (g(t)), and PRI changed in parallel with RWC. A decrease in A resulted from coordinated suppression in leaf conductance. As water stress progressed, A measured in non-photorespiratory conditions (A(1%O2)) became more than 3 times higher compared to that recorded at 21% \{[\}O-2], indicating that photorespiration likely increased in response to water stress. A(1%O2) was significantly correlated with all leaf conductances. A(1%O2) was limited more by g(s) than by g(m), indicating that higher g(m) favors photosynthesis over photorespiration. There was a significant linear correlation between RWC and PRI. Significant non-linear relationships were also found both between PRI and A and PRI and g(t). These data imply that PRI may clearly detect normal and stressed status of holm oak, but it is not very informative when plants are severely stressed. Overall, our data indicate that: a) PRI is an important indicator of leaf water status as evident from RWC; b) because leaf conductance did not limit photosynthesis when photorespiration was suppressed, holm oak, and in general sclerophyllous species, will respond to future elevated \{[\}CO2] significantly more than mesophyllous plants; c) PRI can be used to predict changes in the performance of holm oak subjected to physiological water stress, whereas caution is needed under severe drought. (C) 2014 Friends Science Publishers</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 399-B, PEOPLES COLONY NO 1, FAISALABAD, 38090, PAKISTAN&lt;br/&gt;publisher: FRIENDS SCIENCE PUBL</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rambal, S</style></author><author><style face="normal" font="default" size="100%">Lempereur, M</style></author><author><style face="normal" font="default" size="100%">Limousin, J M</style></author><author><style face="normal" font="default" size="100%">Martin-StPaul, N K</style></author><author><style face="normal" font="default" size="100%">Ourcival, J M</style></author><author><style face="normal" font="default" size="100%">Rodríguez-Calcerrada, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">How drought severity constrains GPP and its partitioning among carbon pools in a Quercus ilex coppice?</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeosciences Discuss.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon sink</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">GPP</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthates</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><publisher><style face="normal" font="default" size="100%">Copernicus Publications</style></publisher><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">8673-8711</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The partitioning of photosynthates toward biomass compartments has a crucial role in the carbon sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought prone forests. We analyzed the fate of GPP in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Gross and net carbon fluxes between the ecosystem and the atmosphere were measured with an eddy-covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy-covariance fluxes with annual productions we managed to close a C budget and derive values of autotrophic and heterotrophic respirations, NPP and carbon use efficiency (CUE, the ratio between NPP and GPP). Average values of yearly NEP, GPP and Reco were 282, 1259 and 977 g C m−2. The corresponding ANPP components were 142.5, 26.4 and 69.6 g C m−2 for leaves, reproductive effort (flowers and fruits) and stems. Gross and net carbon exchange between the ecosystem and the atmosphere were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected, the stem growth, to the least affected, the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease more slightly in response to drought than GPP and NPP, probably due to drought-acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem and highlight the value of maintaining continuous experimental measurements over the long term.</style></abstract><notes><style face="normal" font="default" size="100%">APS</style></notes><research-notes><style face="normal" font="default" size="100%">APS</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Disante, Karen B</style></author><author><style face="normal" font="default" size="100%">Cortina, Jordi</style></author><author><style face="normal" font="default" size="100%">Vilagrosa, Alberto</style></author><author><style face="normal" font="default" size="100%">Fuentes, David</style></author><author><style face="normal" font="default" size="100%">Hernández, Encarni I</style></author><author><style face="normal" font="default" size="100%">Ljung, Karin</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Alleviation of Zn toxicity by low water availability</style></title><secondary-title><style face="normal" font="default" size="100%">Physiologia Plantarum</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">functional traits</style></keyword><keyword><style  face="normal" font="default" size="100%">Heavy metals</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">150</style></volume><pages><style face="normal" font="default" size="100%">n/a--n/a</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Heavy metal contamination and drought are expected to increase in large areas worldwide. However, their combined effect on plant performance has been scantly analyzed. This study examines the effect of Zn supply at different water availabilities on morpho-physiological traits of Quercus suber L. in order to analyze the combined effects of both stresses. Seedlings were treated with four levels of zinc from 3 to 150 µM and exposed to low watering (LW) or high watering (HW) frequency in hydroponic culture, using a growth chamber. Under both watering regimes, Zn concentration in leaves and roots increased with Zn increment in nutrient solution. Nevertheless, at the highest Zn doses, Zn tissue concentrations were almost twice in HW than in LW seedlings. Functional traits as leaf photosynthetic rate and root hydraulic conductivity, and morphological traits as root length and root biomass decreased significantly in response to Zn supply. Auxin levels increased with Zn concentrations, suggesting the involvement of this phytohormone in the seedling response to this element. LW seedlings exposed to 150 µM Zn showed higher root length and root biomass than HW seedlings exposed to the same Zn dose. Our results suggest that low water availability could mitigate Zn toxicity by limiting internal accumulation. Morphological traits involved in the response to both stresses probably contributed to this response.</style></abstract><accession-num><style face="normal" font="default" size="100%">23992347</style></accession-num><notes><style face="normal" font="default" size="100%">APS</style></notes><research-notes><style face="normal" font="default" size="100%">APS</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rosas, Teresa</style></author><author><style face="normal" font="default" size="100%">Galiano, Lucia Lucía</style></author><author><style face="normal" font="default" size="100%">Ogaya, Roma Romà</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Martínez-Vilalta, Jordi</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Martínez-Vilalta, Jordi</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Dynamics of non-structural carbohydrates in three Mediterranean woody species following long-term experimental drought</style></title><secondary-title><style face="normal" font="default" size="100%">FRONTIERS IN PLANT SCIENCE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">crown condition</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Growth</style></keyword><keyword><style  face="normal" font="default" size="100%">long-term</style></keyword><keyword><style  face="normal" font="default" size="100%">non-s</style></keyword><keyword><style  face="normal" font="default" size="100%">non-structural carbohydrates</style></keyword><keyword><style  face="normal" font="default" size="100%">starch</style></keyword><keyword><style  face="normal" font="default" size="100%">throughfall</style></keyword><keyword><style  face="normal" font="default" size="100%">Throughfall manipulation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">FRONTIERS RESEARCH FOUNDATION</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 110, LAUSANNE, 1015, SWITZERLAND</style></pub-location><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">400</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Stored non-structural carbohydrates (NSC) have been proposed as a key determinant of drought resistance in plants. However, the evidence for this role is controversial, as it comes mostly from observational, short-term studies. Here, we take advantage of a long-term experimental throughfall reduction to elucidate the response of NSC to increased drought 14 years after the beginning of the treatment in three Mediterranean resprouter trees (Quercus ilex L., Arbutus unedo L. and Phillyrea latifolia L.). In addition, we selected 20 Q. ilex individuals outside the experimental plots to directly assess the relationship between defoliation and NSC at the individual level. We measured the seasonal course of NSC concentrations in leaves, branches and lignotuber in late winter, late spring, summer, and autumn 2012. Total concentrations of NSC were highest in the lignotuber for all species. In the long-term drought experiment we found significant depletion in concentrations of total NSC in treatment plots only in the lignotuber of A. unedo. At the same time, A. unedo was the only species showing a significant reduction in BAI under the drought treatment during the 14 years of the experiment. By contrast, Q. ilex just reduced stem growth only during the first 4 years of treatment and P latifolia remained unaffected over the whole study period. However, we found a clear association between the concentrations of NSC and defoliation in Q. ilex individuals sampled outside the experimental plots, with lower total concentrations of NSC and lower proportion of starch in defoliated individuals. Taken together, our results suggest that stabilizing processes, probably at the stand level, may have been operating in the long-term to mitigate any impact of drought on NSC levels, and highlight the necessity to incorporate long-term experimental studies of plant responses to drought.</style></abstract><accession-num><style face="normal" font="default" size="100%">24130568</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rosas, Teresa</style></author><author><style face="normal" font="default" size="100%">Galiano, Lucia Lucía</style></author><author><style face="normal" font="default" size="100%">Ogaya, Roma Romà</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Martínez-Vilalta, Jordi</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Martínez-Vilalta, Jordi</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Dynamics of non-structural carbohydrates in three Mediterranean woody species following long-term experimental drought</style></title><secondary-title><style face="normal" font="default" size="100%">FRONTIERS IN PLANT SCIENCE</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">crown condition</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Growth</style></keyword><keyword><style  face="normal" font="default" size="100%">long-term</style></keyword><keyword><style  face="normal" font="default" size="100%">non-s</style></keyword><keyword><style  face="normal" font="default" size="100%">non-structural carbohydrates</style></keyword><keyword><style  face="normal" font="default" size="100%">starch</style></keyword><keyword><style  face="normal" font="default" size="100%">throughfall</style></keyword><keyword><style  face="normal" font="default" size="100%">Throughfall manipulation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3795346&amp;tool=pmcentrez&amp;rendertype=abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">4</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Stored non-structural carbohydrates (NSC) have been proposed as a key determinant of drought resistance in plants. However, the evidence for this role is controversial, as it comes mostly from observational, short-term studies. Here, we take advantage of a long-term experimental throughfall reduction to elucidate the response of NSC to increased drought 14 years after the beginning of the treatment in three Mediterranean resprouter trees (Quercus ilex L., Arbutus unedo L. and Phillyrea latifolia L.). In addition, we selected 20 Q. ilex individuals outside the experimental plots to directly assess the relationship between defoliation and NSC at the individual level. We measured the seasonal course of NSC concentrations in leaves, branches and lignotuber in late winter, late spring, summer, and autumn 2012. Total concentrations of NSC were highest in the lignotuber for all species. In the long-term drought experiment we found significant depletion in concentrations of total NSC in treatment plots only in the lignotuber of A. unedo. At the same time, A. unedo was the only species showing a significant reduction in BAI under the drought treatment during the 14 years of the experiment. By contrast, Q. ilex just reduced stem growth only during the first 4 years of treatment and P latifolia remained unaffected over the whole study period. However, we found a clear association between the concentrations of NSC and defoliation in Q. ilex individuals sampled outside the experimental plots, with lower total concentrations of NSC and lower proportion of starch in defoliated individuals. Taken together, our results suggest that stabilizing processes, probably at the stand level, may have been operating in the long-term to mitigate any impact of drought on NSC levels, and highlight the necessity to incorporate long-term experimental studies of plant responses to drought.</style></abstract><issue><style face="normal" font="default" size="100%">October</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: PO BOX 110, LAUSANNE, 1015, SWITZERLAND&lt;br/&gt;publisher: FRONTIERS RESEARCH FOUNDATION&lt;br/&gt;accession-num: 24130568</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sardans, Jordi</style></author><author><style face="normal" font="default" size="100%">Rivas-Ubach, Albert</style></author><author><style face="normal" font="default" size="100%">Estiarte, Marc</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Field-simulated droughts affect elemental leaf stoichiometry in Mediterranean forests and shrublands</style></title><secondary-title><style face="normal" font="default" size="100%">ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Growth rate hypothesis</style></keyword><keyword><style  face="normal" font="default" size="100%">N:P</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Ontogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">phosphorus</style></keyword><keyword><style  face="normal" font="default" size="100%">Potassium</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">GAUTHIER-VILLARS/EDITIONS ELSEVIER</style></publisher><pub-location><style face="normal" font="default" size="100%">23 RUE LINOIS, 75015 PARIS, FRANCE</style></pub-location><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">20-31</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">This study evaluated the change induced by the year season and by experimentally induced drought on foliar element stoichiometry of the predominant woody species (Quercus ilex and Erica multiflora) in two Mediterranean ecosystems, a forest and a shrubland. This study is based in two long-term (11 yr) field experiments that simulated drought throughout the annual cycle. The effects of experimental droughts were significant but weaker than the changes produced by ontogeny and seasonality. Leaf N and P concentrations were higher in spring (the main growing season) in E. multiflora and, in Q. ilex in autumn (a period of additional growth). Leaf N:P ratios were lower in spring. In Q. ilex, the highest leaf K concentrations and leaf K:P ratios, and the lowest leaf C:K and N:K ratios, occurred in summer, the season when water stress was greatest. In E. multiflora, leaf K concentrations and K:P ratios were highest, and leaf C:K and N:K ratios were lowest in the plants from the drought-treated plots. The plant capacity to change K concentrations in response to seasonality and to drought is at least as great as the capacity to change N and P concentrations. The results underscore the importance of K and its stoichiometry relative to C, N and P in dry environments. These results indicate first, that N:P ratio shifts are not uniquely related to growth rate in Mediterranean plants but also to drought, and second, that there is a need to take into account K in ecological stoichiometry studies of terrestrial plants. (C) 2013 Elsevier Masson SAS. All rights reserved.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Granda, Elena</style></author><author><style face="normal" font="default" size="100%">Julio Camarero, J</style></author><author><style face="normal" font="default" size="100%">Gimeno, Teresa E</style></author><author><style face="normal" font="default" size="100%">Martínez-Fernández, Jesús</style></author><author><style face="normal" font="default" size="100%">Valladares, Fernando</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Intensity and timing of warming and drought differentially affect growth patterns of co-occurring Mediterranean tree species</style></title><secondary-title><style face="normal" font="default" size="100%">EUROPEAN JOURNAL OF FOREST RESEARCH</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Coexistence</style></keyword><keyword><style  face="normal" font="default" size="100%">Dendroecology</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forests</style></keyword><keyword><style  face="normal" font="default" size="100%">Radial growth</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">233 SPRING ST, NEW YORK, NY 10013 USA</style></pub-location><volume><style face="normal" font="default" size="100%">132</style></volume><pages><style face="normal" font="default" size="100%">469-480</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Climate change involves warmer temperatures, altered precipitation patterns, increased climatic variability and, in Mediterranean regions, increased frequency and severity of droughts. Tree species may show different growth responses to these components of climatic change, which may trigger changes in forest composition and dominance. We assessed the influence of recent climatic changes on secondary growth of mature trees from four species co-occurring in a Mediterranean continental forest: Quercus ilex, Quercus faginea, Pinus nigra and Juniperus thurifera. We used dendrochronology to relate radial-growth variables \{[\}earlywood and latewood widths, basal area increment (BAI)] to annual and seasonal climatic variables for the period 1977-2007. Our results showed that Q. faginea BAI has declined, whereas J. thurifera BAI has increased over time while Q. ilex and P. nigra have maintained their growth rates. Growth was mainly favored by higher precipitations and tree size for all species. Reduced growth during extremely dry years was observed for all study species, but all of them except Q. faginea recovered their growth levels 2 years after drought. Our findings illustrate how the effects of climatic changes on growth should include analyses of seasonal climatic trends and extreme events such as severe droughts. We conclude that the seasonal timing of warming and precipitation alterations leading to drought events caused contrasting effects on growth of co-occurring Mediterranean tree species, compromising their future coexistence.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Flexas, J.</style></author><author><style face="normal" font="default" size="100%">Diaz-Espejo, a</style></author><author><style face="normal" font="default" size="100%">Gago, J.</style></author><author><style face="normal" font="default" size="100%">Gallé, a</style></author><author><style face="normal" font="default" size="100%">Galmés, J.</style></author><author><style face="normal" font="default" size="100%">Gulías, J.</style></author><author><style face="normal" font="default" size="100%">Medrano, H.</style></author><author><style face="normal" font="default" size="100%">Díaz-Espejo, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Photosynthetic limitations in mediterranean plants: A review</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biochemical limitation</style></keyword><keyword><style  face="normal" font="default" size="100%">chilling</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conductance limitation</style></keyword><keyword><style  face="normal" font="default" size="100%">stomatal limitation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0098847213001238http://linkinghub.elsevier.com/retrieve/pii/S0098847213001238</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The aim of the present work is to review the literature concerning photosynthesis of Mediterranean plants. First, we briefly review the most important environmental constraints to photosynthesis, i.e. chilling winter temperatures and summer drought. Then, the review specifically focus on the photosynthetic capacity and photosynthetic limitations of Mediterranean plants under non-stress conditions, to test the general assumption that that the photosynthetic capacity of Mediterranean plants is lower than that of plants from other biomes. It is shown that Mediterranean plants of different life forms and leaf types present, on average, similar photosynthetic capacity to plants from any other biome. However, the mechanisms potentially limiting maximum photosynthesis differ between Mediterranean and non-Mediterranean species. For instance, Mediterranean plants compensate their lower mesophyll conductance to CO2 (gm) with a larger velocity of carboxylation (Vc,max) to achieve similar photosynthesis rates (AN) to non-Mediterranean plants, both factors being associated to a larger leaf mass area (LMA) in Mediterranean species. In contrast, stomatal conductance (gs) was found to be lower only in Mediterranean sclerophytes. On the other hand, Mediterranean sclerophytes and malacophytes (but not herbs and mesophytes) show higher mean intrinsic water use efficiency (AN / gs) due to a combination of higher gm / gs and AN per unit CO2 concentration in the chloroplasts, i.e. carboxylation efficiency. represent specific adaptations of Mediterranean plants to their environment, leading these plants to achieve high AN despite their large LMA, and Mediterranean ecosystems to be Accepted Manuscript The described variations in the mechanistic components of photosynthesis may among those presenting the largest net primary productivities worldwide</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Schnabel, S</style></author><author><style face="normal" font="default" size="100%">Gomez GUTIÉRREZ, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The role of interannual rainfall variability on runoff generation in a small dry sub-humid watershed with disperse tree cover</style></title><secondary-title><style face="normal" font="default" size="100%">Cuadernos de Investigación Geográfica</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">discharge</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">empirical modelling</style></keyword><keyword><style  face="normal" font="default" size="100%">RAINFALL</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil moisture</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">259-285</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Recent studies in small experimental catchments under Mediterranean-type climate revealed a complex hydrological catchment response, presenting saturation excess runoff generation and, to a minor degree, infiltration excess flow. Many of these catchments, however, belong to areas with sub-humid or humid Mediterranean climate. Catchment studies were carried out since 1991 in savannah-like grazed land (dehesas), which are widespread in south-western Spain, and also elsewhere in the Mediterranean. Albeit knowledge gained by previous studies, no thorough analysis has been carried out on the temporal variation of discharge production using the complete dataset. The objectives include i) an analysis of the temporal variation of discharge and rainfall at different temporal scales, ii) exploration of the role of antecedent soil moisture conditions in runoff production, iii) empirical modeling of rainfall- runoff relationships at the event scale and iv) definition of the importance of interannual rainfall variation on discharge production. The analysis were based on rainfall and runoff which were monitored at a time resolution of 5 minutes and periodically measured soil moisture from various depth in the valley bottom. Regression analysis as well as the comparison of hydrographs illustrate on the importance of antecedent rainfall conditions. Soil moisture in the valley bottom was crucial to understand the hydrological behaviour of the catchment. A soil moisture threshold of 0.37 m3 m-3 was defined above which runoff coefficients increase sharply. This situation is reached with 170 mm of antecedent rain falling in a continuous way. The results indicate that saturation excess flow and preferential subsurface flow processes are responsible of most of the runoff generated. Hortonian type overland flow dominates under dry soil conditions and is produced by high intensity rainfall. Non-linear regression analysis with data grouped according to antecedent catchment conditions produced highly significant regression models, explaining event discharge with three variables: Maximum 60-minute rainfall intensity (I60), event rainfall minus I60 and mean antecedent daily rainfall. Variability of monthly runoff is best explained by interannual rainfall variation rather than by mean seasonal distribution. During droughts, which are a common feature in the Mediterranean, discharge was very low. Runoff is highly concentrated in time with 10% of the months accounting for 85% of total discharge.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">David, Teresa S.</style></author><author><style face="normal" font="default" size="100%">Pinto, Clara A.</style></author><author><style face="normal" font="default" size="100%">Nadezhdina, Nadezhda</style></author><author><style face="normal" font="default" size="100%">Kurz-Besson, Cathy</style></author><author><style face="normal" font="default" size="100%">Henriques, Manuel O.</style></author><author><style face="normal" font="default" size="100%">Quilhó, Teresa</style></author><author><style face="normal" font="default" size="100%">Čermák, Jan</style></author><author><style face="normal" font="default" size="100%">Chaves, M. Manuela</style></author><author><style face="normal" font="default" size="100%">Pereira, João S.</style></author><author><style face="normal" font="default" size="100%">David, Jorge S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root functioning, tree water use and hydraulic redistribution in Quercus suber trees: A modeling approach based on root sap flow</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">groundwater</style></keyword><keyword><style  face="normal" font="default" size="100%">soil water</style></keyword><keyword><style  face="normal" font="default" size="100%">Stable isotopes</style></keyword><keyword><style  face="normal" font="default" size="100%">xylem anatomy</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0378112713004441</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">307</style></volume><pages><style face="normal" font="default" size="100%">136 - 146</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean evergreen oaks have to survive a long summer drought. Roots may play a relevant role under these conditions. We studied their structure and function in a mature Quercus suber L. tree in central Portugal. The root system was mapped till the lowest water table level (4.5 m depth). Xylem anatomy was analyzed in a vertical profile belowground. Sap flow was continuously monitored for 1.5 yrs in the stem and roots of this intensively studied tree (heat field deformation method) and in the stem of four trees (Granier method), in relation to environmental variables and predawn leaf water potential. The sources of water uptake were assessed by stable isotope analyses in summer. Results showed a dimorphic root system with a network of superficial roots linked to sinker roots, and a taproot diverting into tangles of deep fine roots submerged for long periods, with parenchyma aerenchyma. Transpiration was not restricted in summer due to root access to groundwater. The isotopic δ18O signature of twig xylem water was similar to that of groundwater in the dry season. Two functional types of superficial roots were identified: shallow connected and deep connected roots. A modeling approach was built considering that each superficial root was linked to a sinker, with part of the root deep connected (between the stem and the sinker) and part shallow connected (between the sinker and topsoil). This conceptual framework simulated tree stem sap flow from root sap flow with a high efficiency (R2 = 0.85) in four plot trees. On an annual basis, soil water and groundwater contributions were 69.5% and 30.5% of stem flow, respectively. Annual hydraulic lift and hydraulic descent were 0.9% and 37.0% of stem flow, respectively. The trees maximize the exploitation of the environmental resources by using the topsoil water during most of the year, and groundwater together with hydraulic lift (nutrient supply) in the dry summer. This study shows that a dimorphic root system, with roots reaching groundwater, is an efficient strategy of Q. suber trees to cope with seasonal drought. Knowledge of the functional behavior of Q. suber trees under shallow water table conditions may contribute to the definition of better adapted management practices and to anticipate their responses to climate change.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Catoni, R</style></author><author><style face="normal" font="default" size="100%">Varone, L</style></author><author><style face="normal" font="default" size="100%">Gratani, L</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Variations in leaf respiration across different seasons for Mediterranean evergreen species</style></title><secondary-title><style face="normal" font="default" size="100%">PHOTOSYNTHETICA</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Leaf respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreen species</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">51</style></volume><pages><style face="normal" font="default" size="100%">295-304</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Leaf respiration (R (L)) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R (L) trend during the year, with the lowest rates \{[\}0.83 +/- 0.43 mu mol(CO2) m(-2) s(-1), mean value of the considered species] in winter, in response to low air temperatures. Higher R (L) were reached in spring \{[\}2.44 +/- 1.00 mu mol(CO2) m(-2) s(-1), mean value] during the favorable period, and in summer \{[\}3.17 +/- 0.89 mu mol(CO2) m(-2) s(-1)] during drought. The results of the regression analysis showed that 42% of R (L) variations depended on mean air temperature and 13% on total monthly rainfall. Among the considered species, C. incanus, was characterized by the highest R (L) in drought \{[\}4.93 +/- 0.27 mu mol(CO2) m(-2) s(-1)], low leaf water potential at predawn (I-pd= -1.08 +/- 0.18 MPa) and midday (I-md = -2.75 +/- 0.11 MPa) and low relative water content at predawn (RWCpd = 80.5 +/- 3.4%) and midday (RWCmd = 67.1 +/- 4.6%). Compared to C. incanus, the sclerophyllous species (Q. ilex, P. latifolia, P. lentiscus, A. unedo) and the liana (S. aspera), had lower R (L) \{[\}2.72 +/- 0.66 mu mol(CO2) m(-2) s(-1), mean value of the considered species], higher RWCpd (91.8 +/- 1.8%), RWCmd (82.4 +/- 3.2%), I-pd (-0.65 +/- 0.28 MPa) and I-md (-2.85 +/- 1.20 MPa) in drought. The narrow-leaved species (E. multiflora, R. officinalis, and E. arborea) were in the middle. The coefficients, proportional to the respiration increase for each 10A degrees C rise (Q(10)), ranging from 1.49 (E. arborea) to 1.98 (A. unedo) were indicative of the different sensitivities of the considered species to air temperature variation.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Poorter, Lourens</style></author><author><style face="normal" font="default" size="100%">Lianes, Elena</style></author><author><style face="normal" font="default" size="100%">Moreno-de las Heras, Mariano</style></author><author><style face="normal" font="default" size="100%">Zavala, Miguel A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Architecture of Iberian canopy tree species in relation to wood density, shade tolerance and climate</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Architecture</style></keyword><keyword><style  face="normal" font="default" size="100%">Crown traits</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">shade tolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">Tree height</style></keyword><keyword><style  face="normal" font="default" size="100%">Wood density</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">213</style></volume><pages><style face="normal" font="default" size="100%">707-722</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Tree architecture has important consequences for tree performance as it determines resource capture, mechanical stability and dominance over competitors. We analyzed architectural relationships between stem and crown dimensions for 13 dominant Iberian canopy tree species belonging to the Pinaceae (six Pinus species) and Fagaceae (six Quercus species and Fagus sylvatica) and related these architectural traits to wood density, shade tolerance and climatic factors. Fagaceae had, compared with Pinaceae, denser wood, saplings with wider crowns and adults with larger maximal crown size but smaller maximal height. In combination, these traits enhance light acquisition and persistence in shaded environments; thus, contributing to their shade tolerance. Pinaceae species, in contrast, had low-density wood, allocate more resources to the formation of the central trunk rather than to branches and attained taller maximal heights, allowing them to grow rapidly in height and compete for light following disturbances; thus, contributing to their high light requirements. Wood density had a strong relationship with tree architecture, with dense-wooded species having smaller maximum height and wider crowns, probably because of cheaper expansion costs for producing biomechanically stable branches. Species from arid environments had shorter stems and shallower crowns for a given stem diameter, probably to reduce hydraulic path length and assure water transport. Wood density is an important correlate of variation in tree architecture between species and the two dominant families, with potentially large implications for their resource foraging strategies and successional dynamics.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Barbeta, Adrià</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparative study of diurnal and nocturnal sap flow of Quercus ilex and Phillyrea latifolia in a Mediterranean holm oak forest in Prades (Catalonia, NE Spain)</style></title><secondary-title><style face="normal" font="default" size="100%">Trees</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">á</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">ilex á sap flow</style></keyword><keyword><style  face="normal" font="default" size="100%">nocturnal sap flow</style></keyword><keyword><style  face="normal" font="default" size="100%">nocturnal sap flow á</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia á quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s00468-012-0741-4http://link.springer.com/10.1007/s00468-012-0741-4</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">26</style></volume><pages><style face="normal" font="default" size="100%">1651 - 1659</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Droughts are a cyclical disturbance in Mediterranean ecosystems and climate change models forecast an increase of their frequency and severity. Some experimental and observational studies have shown that cooccurring species may cope with drier conditions with different strategies and present different responses. Here, we investigate sap ﬂow response to drought in order to explain the observed differential growth and mortality of Quercus ilex and Phillyrea latifolia at Prades Holm oak forest (NE Spain). We measured sap ﬂow of these species and compared their diurnal, nocturnal and seasonal patterns and their relationship with environmental variables. Both species described qualitatively similar daily patterns, either during daylight or night. Sap ﬂow rates were signiﬁcantly higher in P. latifolia except in autumn and spring. P. latifolia was more sensitive to soil moisture. Nocturnal sap ﬂow was detected in both species with no signiﬁcant differences and hourly rates suffered a progressive increase from 3 a.m. to dawn in most sampled nights. Our results indicate a better adaptation of P. latifolia to this site as it can take better advantage of wet periods while maintaining higher sap ﬂow rates during dry periods. Along with previous ecophysiological studies at the same location it may be inferred that at its drier distributional limit Q. ilex would be at disadvantage with respect to other species like P. latifolia, as the latter would cope better with increasing xeric conditions already occurring and further predicted for Mediterranean ecosystems. Our results also show nocturnal sap ﬂow to be relevant in individual water losses in these two species as they can be up to 35–40 % of daily sap ﬂow. Further research on the underlying mechanisms of this nocturnal sap ﬂow is required since it may also enhance early morning CO2 ﬁxation or nutrient supply to leaves.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pasho, Edmond</style></author><author><style face="normal" font="default" size="100%">Camarero, J Julio</style></author><author><style face="normal" font="default" size="100%">Luis, Martín</style></author><author><style face="normal" font="default" size="100%">Vicente-Serrano, Sergio M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Factors driving growth responses to drought in Mediterranean forests</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dendrochronology</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">iberian peninsula</style></keyword><keyword><style  face="normal" font="default" size="100%">Radial growth</style></keyword><keyword><style  face="normal" font="default" size="100%">Standardized precipitation index</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">131</style></volume><pages><style face="normal" font="default" size="100%">1797-1807</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We lack information regarding the main factors driving growth responses to drought in tree species with different vulnerability against this stressor and considering sites with contrasting climatic conditions. In this paper, we identify the main drivers controlling growth response to a multi-scalar drought index (Standardized Precipitation Index, SPI) in eight tree species (Abies alba, Pinus halepensis, Quercus faginea, Pinus sylvestris, Quercus ilex, Pinus pinea, Pinus nigra, Juniperus thurifera). We sampled forests growing across a pronounced climatic gradient under Mediterranean conditions in north-eastern Spain. To summarize the patterns of growth responses to drought, we used principal component analysis (PCA). To determine the main factors affecting growth responses to drought, correlation and regression analyses were carried out using a set of abiotic (climate, topography, soil type) and biotic (Normalized Difference Vegetation Index, Enhanced Vegetation Index, tree-ring width, diameter at breast height) predictors and the PCs loadings as response variables. The PCA analysis detected two patterns of growth responses to drought corresponding to xeric and mesic sites, respectively. The regression analyses indicated that growth responses to drought in xeric forests were mainly driven by the annual precipitation, while in mesic sites the annual water balance was the most important driver. The management of Mediterranean forests under the forecasted warmer and drier conditions should focus on the main local factors modulating the negative impacts of drought on tree growth in xeric and mesic sites.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Fernández-Martínez, Marcos</style></author><author><style face="normal" font="default" size="100%">Belmonte, Jordina</style></author><author><style face="normal" font="default" size="100%">MARÍA ESPELTA, JOSEP</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Masting in oaks: Disentangling the effect of flowering phenology, airborne pollen load and drought</style></title><secondary-title><style face="normal" font="default" size="100%">Acta Oecologica</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acorns</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">Pollination efﬁciency hypothesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus spp.</style></keyword><keyword><style  face="normal" font="default" size="100%">Resource-based hypotheses</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S1146609X12000586</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">43</style></volume><pages><style face="normal" font="default" size="100%">51 - 59</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Quercus species exhibit an extreme inter-annual variability in seed production often synchronized over large geographical areas (masting). Since this reproductive behavior is mostly observed in anemophilous plants, pollination efﬁciency is suggested as one hypothesis to explain it, although resource-based hypotheses are also suggested as alternatives. We analyzed the effect of ﬂowering phenology, airborne pollen presence and meteorological conditions in the pattern of acorn production in mixed evergreendeciduous oak forests (Quercus ilex and Quercus pubescens) in NE Spain for twelve years (1998e2009). In both oaks, higher temperatures advanced the onset of ﬂowering and increased the amount of airborne pollen. Nevertheless, inter-annual differences in pollen production did not inﬂuence acorn crop size. Acorn production was enhanced by a delay in ﬂowering onset in Q. ilex but not in Q. pubescens. This suggests that in perennial oaks a larger number of photosynthates produced before ﬂowering could beneﬁt reproduction while the lack of effects on deciduous oaks could be because these species ﬂush new leaves and ﬂowers at the same time. Notwithstanding this effect, spring water deﬁcit was the most relevant factor in explaining inter-annual variability in acorn production in both species. Considering that future climate scenarios predict progressive warmer and dryer spring seasons in the Mediterranean Basin, this might result in earlier onsets of ﬂowering and higher water deﬁcits that would constrain acorn production.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Andivia, Enrique</style></author><author><style face="normal" font="default" size="100%">Carevic, Felipe</style></author><author><style face="normal" font="default" size="100%">FERNÁNDEZ, MANUEL</style></author><author><style face="normal" font="default" size="100%">Alejano, Reyes</style></author><author><style face="normal" font="default" size="100%">VÁZQUEZ-PIQUÉ, JAVIER</style></author><author><style face="normal" font="default" size="100%">TAPIAS, RAÚL</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal evolution of water status after outplanting of two provenances of Holm oak nursery seedlings</style></title><secondary-title><style face="normal" font="default" size="100%">New Forests</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Adaptation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Field performance</style></keyword><keyword><style  face="normal" font="default" size="100%">Physiological traits</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s11056-012-9347-3</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">43</style></volume><pages><style face="normal" font="default" size="100%">815 - 824</style></pages><isbn><style face="normal" font="default" size="100%">1105601293</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Forest restoration programs using Holm oak (Quercus ilex ssp. ballota [Desf.] Samp.) have had limited success. The effect of plant provenance on plantation success is uncertain, although some previous studies suggest that some provenances may be better able to tolerate stress. We studied the tolerance to drought in seedlings from two Spanish provenances of Holm oak before and after outplanting. One provenance was from a continental climate with cold winters (GR) and the other was from a xeric climate (HU). Seedlings were subjected to a water stress test in the nursery during the summer and survival was visually assessed after 2 weeks. In addition, 35 healthy seedlings of each provenance that were not subjected to the water stress tests were used for outplanting experiment. In these plants the seasonal changes in water potential at dawn (W), speciﬁc leaf area (SLA), cuticular transpiration (Ec ), and loss of xylem hydraulic conductance of twigs (PLC) were measured over 18 months. After the water stress test in summer, mortality was 44.3 % for GR seedlings and 12.6 % for HU seedlings. In addition there were differences between the two provenances in plant water status after planting. The HU provenance had a better water status and was more water conservative in the summer (higher W, lower Ec , lower PLC), but not in the winter. The different drought tolerance and water relations parameters of these two provenances indicate that provenance should be considered in forest restoration and conservation programs involving Holm oak.</style></abstract><issue><style face="normal" font="default" size="100%">5-6</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Penuelas, J</style></author><author><style face="normal" font="default" size="100%">Rico, L</style></author><author><style face="normal" font="default" size="100%">Ogaya, R</style></author><author><style face="normal" font="default" size="100%">Jump, A S</style></author><author><style face="normal" font="default" size="100%">Terradas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Summer season and long-term drought increase the richness of bacteria and fungi in the foliar phyllosphere of Quercus ilex in a mixed Mediterranean forest</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteria: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacteria: growth &amp; development</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial TRF richness</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodiversity</style></keyword><keyword><style  face="normal" font="default" size="100%">colonisation time</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Droughts</style></keyword><keyword><style  face="normal" font="default" size="100%">endophytes</style></keyword><keyword><style  face="normal" font="default" size="100%">epiphytes</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar and epiphytic microbial diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar phyllosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungal</style></keyword><keyword><style  face="normal" font="default" size="100%">fungal TRF richness</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungal: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">fungi</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungi: genetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungi: growth &amp; development</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean Region</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Plant Leaves: microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Polymorphism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus: microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Restriction Fragment Length</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasonality</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasons</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees</style></keyword><keyword><style  face="normal" font="default" size="100%">Trees: microbiology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">565-575</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We explored the changes in richness, diversity and evenness of epiphytic (on the leaf surface) and endophytic (within leaf tissues) bacteria and fungi in the foliar phyllosphere of Quercus ilex, the dominant tree species of Mediterranean forests. Bacteria and fungi were assessed during ontogenic development of the leaves, from the wet spring to the dry summer season in control plots and in plots subjected to drought conditions mimicking those projected for future decades. Our aim was to monitor succession in microbiota during the colonisation of plant leaves and its response to climate change. Ontogeny and seasonality exerted a strong influence on richness and diversity of the microbial phyllosphere community, which decreased in summer in the whole leaf and increased in summer in the epiphytic phyllosphere. Drought precluded the decrease in whole leaf phyllosphere diversity and increased the rise in the epiphytic phyllosphere. Both whole leaf bacterial and fungal richness decreased with the decrease in physiological activity and productivity of the summer season in control trees. As expected, the richness of epiphytic bacteria and fungi increased in summer after increasing time of colonisation. Under summer dry conditions, there was a positive relationship between TRF (terminal restriction fragments) richness and drought, both for whole leaf and epiphytic phyllosphere, and especially for fungal communities. These results demonstrate that changes in climate are likely to significantly alter microbial abundance and composition of the phyllosphere. Given the diverse functions and large number of phyllospheric microbes, the potential functional implications of such community shifts warrant exploration.</style></abstract><accession-num><style face="normal" font="default" size="100%">22289059</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Monson, Russell K.</style></author><author><style face="normal" font="default" size="100%">Jones, Ryan T.</style></author><author><style face="normal" font="default" size="100%">Rosenstiel, Todd N.</style></author><author><style face="normal" font="default" size="100%">Schnitzler, Jörg-Peter</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Why only some plants emit isoprene.</style></title><secondary-title><style face="normal" font="default" size="100%">Plant, cell &amp; environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">ferns</style></keyword><keyword><style  face="normal" font="default" size="100%">phloem</style></keyword><keyword><style  face="normal" font="default" size="100%">phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">substrate</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">thermotolerance</style></keyword><keyword><style  face="normal" font="default" size="100%">ﬁtness</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/22998549</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Isoprene (2-methyl-1,3-butadiene) is emitted from many plants and it appears to have an adaptive role in protecting leaves from abiotic stress. However, only some species emit isoprene. Isoprene emission has appeared and been lost many times independently during the evolution of plants. As an example, our phylogenetic analysis shows that isoprene emission is likely ancestral within the family Fabaceae (= Leguminosae), but that it has been lost at least 16 times and secondarily gained at least 10 times through independent evolutionary events. Within the division Pteridophyta (ferns), we conservatively estimate that isoprene emissions have been gained five times and lost two times through independent evolutionary events. Within the genus Quercus (oaks), isoprene emissions have been lost from one clade, but replaced by a novel type of light-dependent monoterpene emissions that uses the same metabolic pathways and substrates as isoprene emissions. This novel type of monoterpene emissions has appeared at least twice independently within Quercus, and has been lost from 9% of the individuals within a single population of Quercus suber. Gain and loss of gene function for isoprene synthase is possible through relatively few mutations. Thus, this trait appears frequently in lineages; but, once it appears, the time available for evolutionary radiation into environments that select for the trait is short relative to the time required for mutations capable of producing a non-functional isoprene synthase gene. The high frequency of gains and losses of the trait and its heterogeneous taxonomic distribution in plants may be explained by the relatively few mutations necessary to produce or lose the isoprene synthase gene combined with the assumption that isoprene emission is advantageous in a narrow range of environments and phenotypes.</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;accession-num: 22998549</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Casals, Pere</style></author><author><style face="normal" font="default" size="100%">Lopez-Sangil, Luis</style></author><author><style face="normal" font="default" size="100%">Carrara, Arnaud</style></author><author><style face="normal" font="default" size="100%">Gimeno, Cristina</style></author><author><style face="normal" font="default" size="100%">Nogués, Salvador</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Autotrophic and heterotrophic contributions to short-term soil CO 2 efflux following simulated summer precipitation pulses in a Mediterranean dehesa</style></title><secondary-title><style face="normal" font="default" size="100%">Global Biogeochemical Cycles</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">d13C</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">precipitation manipulation (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 efflux</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.agu.org/pubs/crossref/2011/2010GB003973.shtml</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">25</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Autotrophic and heterotrophic components of soil CO2 efflux may have differential responses to environmental factors, so estimating the relative contribution of each component during summer precipitation pulses is essential to predict C balance in soils experiencing regular drought conditions. As even small summer rains induced high instantaneous soil respiration rates in Mediterranean wooded grasslands, we hypothesized that standing dead mass, surface litter, and topsoil layer could play a dominant role in the initial flush of CO2 produced immediately after soil rewetting; in contrast, soil CO2 effluxes during drought periods should be mostly derived from tree root activity. In a grazed dehesa, we simulated four summer rain events and measured soil CO2 efflux discontinuously, estimating its d 13 C through a Keeling plot nonsteady state static chamber approach. In addition, we estimated litter contribution to soil CO2 efflux and extracted soil available C fractions (K2SO4‐extracted C and chloroform‐fumigated extracted C). The d 13 C‐CO2 from in‐tube incubated excised tree roots and rewetted root‐free soil was −25.0‰ (±0.2) and −28.4‰ (±0.2), respectively. Assuming those values as end‐members’ sources, the autotrophic component of soil CO2 efflux was dominant during the severe drought, whereas the heterotrophic contribution dominated from the very beginning of precipitation pulses. As standing dead mass and fresh litter contribution was low (&lt;25%) in the first day and negligible after, we concluded that CO2 efflux after rewetting was mostly derived from microbial mineralization of available soil organic C fractions.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Asensio, Dolores</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Chlorophyll fluorescence responses to temperature and water availability in two co-dominant Mediterranean shrub and tree species in a long-term field experiment simulating climate change</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Chlorophyll ﬂuorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Cold</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">evergreen leaves</style></keyword><keyword><style  face="normal" font="default" size="100%">Fv/Fm</style></keyword><keyword><style  face="normal" font="default" size="100%">Heat</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S009884721100178X</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">73</style></volume><pages><style face="normal" font="default" size="100%">89 - 93</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A rain exclusion experiment simulating drought conditions expected in Mediterranean areas for the following decades (15% decrease in soil moisture) is being conducted since 1999 in a Mediterranean holm oak forest to study its response to the forecasted climatic changes for the coming decades. The maximum PSII quantum yield of primary photochemistry (Fv/Fm) was measured in Quercus ilex, and Phillyrea latifolia, the co-dominant species of the studied forest, from 1999 to 2009 in four plots: two of them were control plots and the other two plots received the rain exclusion treatment. In both species, the Fv/Fm values were highly dependent on air temperatures, and in a second term, in water availability. P. latifolia was the species with the larger decrease in Fv/Fm values induced by low air temperatures, while in hot seasons, the Fv/Fm values in P. latifolia were even higher than in Q. ilex. Rainfall exclusion decrease Fv/Fm values signiﬁcantly only in few monitoring dates. The most drought resistant species P. latifolia was more affected by the experimental rainfall exclusion than Q. ilex that instead lost number of leaves per tree. There was a synergic effect of drought stress and winter cold in P. latifolia not observed in Q. ilex, but a more conservative strategy in P. latifolia maintaining leaves with a down-regulation of the linear photosynthetic electron transport. These results indicate that, although other physiological and reproductive strategies at whole plant level must be also taken into account, the warmer and drier environment expected for the following decades could favour the species more sensitive to cold and more resistant to drought, the shrub P. latifolia, in detriment of the tree Q. ilex as already observed in the ﬁeld after severe heat-drought episodes.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Padilla, Francisco M</style></author><author><style face="normal" font="default" size="100%">Miranda, Juan de Dios</style></author><author><style face="normal" font="default" size="100%">Ortega, Rafael</style></author><author><style face="normal" font="default" size="100%">Hervás, Manuel</style></author><author><style face="normal" font="default" size="100%">Sánchez, Joaquín</style></author><author><style face="normal" font="default" size="100%">Pugnaire, Francisco I</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Does shelter enhance early seedling survival in dry environments? A test with eight Mediterranean species</style></title><secondary-title><style face="normal" font="default" size="100%">Applied Vegetation Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Arid environments</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest restoration</style></keyword><keyword><style  face="normal" font="default" size="100%">tree shelters</style></keyword><keyword><style  face="normal" font="default" size="100%">woody seedlings</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">31-39</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Question: Do solid-walled polyethylene tubes and mesh fabric tubes improve the short-term survival of eight Mediterranean tree and shrub species often used in the restoration of arid environments? Location: We conducted two experimental plantations in degraded field sites in the province of Almería (SE Spain), under arid Mediterranean conditions. Methods: One-year-old seedlings of Ceratonia siliqua, Juniperus phoenicea, Olea europaea, Pinus halepensis, Pinus pinaster, Quercus coccifera, Quercus ilex and Tetraclinis articulata were planted either sheltered by one of the above shelter tubes, or by being left unsheltered. Survival was recorded the first growing season after planting, which was a very dry season. Results: Overall, seedling survival ranged from as little as 0% to 24%, and tree shelters consistently enhanced survival in Quercus species only, ranging from 16% in walled shelters to 8% in mesh shelters. Shelters failed to boost survival in the six remaining species. Conclusion: The results of this study suggest that both walled and mesh shelters were mostly ineffective at increasing seedling survival for the Mediterranean species used in this experiment; these species coincide with those used in restoration programs. The use of shelters in restoration programs conducted in arid environments should be reconsidered, while walled shelters might be advisable for Mediterranean Quercus species only. Further research is necessary to develop and assess improved types of shelters for arid environments.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Richard, Franck</style></author><author><style face="normal" font="default" size="100%">Roy, Melanie</style></author><author><style face="normal" font="default" size="100%">Shahin, Oula</style></author><author><style face="normal" font="default" size="100%">Sthultz, Christopher</style></author><author><style face="normal" font="default" size="100%">Duchemin, Myriam</style></author><author><style face="normal" font="default" size="100%">Joffre, Richard</style></author><author><style face="normal" font="default" size="100%">Selosse, Marc-André</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Ectomycorrhizal communities in a Mediterranean forest ecosystem dominated by Quercus ilex: seasonal dynamics and response to drought in the surface organic horizon</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of Forest Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">ectomycorrhizal communities</style></keyword><keyword><style  face="normal" font="default" size="100%">Global change</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forests</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s13595-010-0007-5</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">57 - 68</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">• Introduction Millions of hectares of Quercus ilex forests dominate disturbed landscapes in the western part of the Mediterranean basin. Although these forests are very widespread, little is known about the composition and structure of their associated ectomycorrhizal fungal communities. • Results and discussion We examined seasonal patterns in ectomycorrhizal communities and their response to increased drought using a rainfall exclusion experiment established in a Q. ilex coppice since 2003. Ectomycorrhizae were sampled four times in 2007–2009. By sequencing fungal ITS, we identified 129 species in 1,147 sequenced ectomycorrhizal root tips. The fungal community in the surface organic horizon was well described by the logseries theoretical model, with 47.9% of singleton species. The composition of the community was strongly dominated by Basidiomycetes, with three families (Thelephoraceae, Russulaceae and Cortinariaceae) accounting for 72.9% of the root tips. Relative abundance of Russulaceae and Thelephoraceae showed pronounced seasonal shifts. Experimental reduction of rainfall resulted in significant shifts in community composition and seasonal fluctuations but had no effect on global richness of the community. • Conclusions Together, these results suggest that the predicted rainfall reduction in this region due to climate change will lead to shifts</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pasho, Edmond</style></author><author><style face="normal" font="default" size="100%">Camarero, J. Julio</style></author><author><style face="normal" font="default" size="100%">de Luis, Martín</style></author><author><style face="normal" font="default" size="100%">Vicente-Serrano, Sergio M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Impacts of drought at different time scales on forest growth across a wide climatic gradient in north-eastern Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest Meteorology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dendrochronology</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest growth</style></keyword><keyword><style  face="normal" font="default" size="100%">Impacts</style></keyword><keyword><style  face="normal" font="default" size="100%">NE Spain</style></keyword><keyword><style  face="normal" font="default" size="100%">Standardized precipitation index (SPI)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S016819231100253X</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">151</style></volume><pages><style face="normal" font="default" size="100%">1800 - 1811</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We analyzed the impact of drought measured on different time-scales on radial growth of eight tree species during the period 1950–2005 growing across a wide climatic gradient encompassing semiarid Mediterranean woodlands and wet mountain forests in north-eastern Spain. A drought index (standardized precipitation index, SPI) at different time scales (1–48 months) was correlated with chronologies of ring width to determine the signiﬁcant time scale at which drought affected most tree growth. The ﬁndings indicated that the impact of drought on growth varied noticeably among species and sites. Two distinct patterns were clearly observed considering spatial and temporal differences in the response of species to drought. Species growing in xeric sites (Pinus and Quercus species and Juniperus thurifera) showed the highest responses to SPI time-scales of 9–11 months while those located in mesic sites (Abies alba, Pinus sylvestris) did respond more to SPI time scales shorter than 5 months. The SPI-growth correlations were signiﬁcant, although weak, up to 30 months in xeric sites while no consistent association was observed at higher time scales. Important seasonal differences were noticed in the SPI-growth associations. Species growing in xeric areas responded to spring-summer SPI while those distributed in mesic sites responded more to summer SPI. Our ﬁndings should be useful to understand forest responses to climate change, including an increasing frequency of severe droughts, and to adapt appropriate management strategies to mitigate the impact of drought on tree growth.</style></abstract><issue><style face="normal" font="default" size="100%">12</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sánchez-Humanes, Belén</style></author><author><style face="normal" font="default" size="100%">Espelta, Josep Maria</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Increased drought reduces acorn production in Quercus ilex coppices: thinning mitigates this effect but only in the short term</style></title><secondary-title><style face="normal" font="default" size="100%">Forestry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acorn production</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forest (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">thinning</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://forestry.oxfordjournals.org/content/84/1/73.abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">84</style></volume><pages><style face="normal" font="default" size="100%">73 - 82</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In order to explore the effects of climate change on Mediterranean regenerating forests, we experimentally assessed the effects of increased drought on the reproductive attributes of Quercus ilex over a 4-year period (2005–2008). We also investigated whether traditional thinning (selection of one to a few stems per stump) could mitigate the consequences of increased drought in oak coppices. Increased drought reduced the number of reproductive trees, mean number of female flowers produced and acorn crop size, although most of these effects appeared only in the last 2 years of the experiment. In a different way, thinning enhanced all reproductive attributes, but its main effects were transient and covered only 1 or 2 years after the application of the treatments. Our results indicate that a moderate reduction in rainfall (15 per cent) reduces the reproductive ability of Q. ilex. This may have long-term negative consequences for recruitment as well as for the fauna feeding on acorns. Although traditional thinning may mitigate the consequences of increased drought, it has a remarkably short-term effect. This highlights the need to re-examine traditional forestry practices as potential adaptive strategies for coping with climate change in Mediterranean regenerating forests.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">10.1093/forestry/cpq04510.1093/forestry/cpq045</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Linares, Juan C</style></author><author><style face="normal" font="default" size="100%">Taiqui, Lahcen</style></author><author><style face="normal" font="default" size="100%">Julio Camarero, Jesus</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Increasing Drought Sensitivity and Decline of Atlas Cedar (Cedrus atlantica) in the Moroccan Middle Atlas Forests</style></title><secondary-title><style face="normal" font="default" size="100%">FORESTS</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">basal area increment</style></keyword><keyword><style  face="normal" font="default" size="100%">Cedrus atlantica</style></keyword><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Dendroecology</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest structure</style></keyword><keyword><style  face="normal" font="default" size="100%">partial redundancy analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year></dates><publisher><style face="normal" font="default" size="100%">MDPI AG</style></publisher><pub-location><style face="normal" font="default" size="100%">POSTFACH, CH-4005 BASEL, SWITZERLAND</style></pub-location><volume><style face="normal" font="default" size="100%">2</style></volume><pages><style face="normal" font="default" size="100%">777-796</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">An understanding of the interactions between climate change and forest structure on tree growth are needed for decision making in forest conservation and management. In this paper, we investigated the relative contribution of tree features and stand structure on Atlas cedar (Cedrus atlantica) radial growth in forests that have experienced heavy grazing and logging in the past. Dendrochronological methods were applied to quantify patterns in basal-area increment and drought sensitivity of Atlas cedar in the Middle Atlas, northern Morocco. We estimated the tree-to-tree competition intensity and quantified the structure in Atlas cedar stands with contrasting tree density, age, and decline symptoms. The relative contribution of tree age and size and stand structure to Atlas cedar growth decline was estimated by variance partitioning using partial-redundancy analyses. Recurrent drought events and temperature increases have been identified from local climate records since the 1970s. We detected consistent growth declines and increased drought sensitivity in Atlas cedar across all sites since the early 1980s. Specifically, we determined that previous growth rates and tree age were the strongest tree features, while Quercus rotundifolia basal area was the strongest stand structure measure related to Atlas cedar decline. As a result, we suggest that Atlas cedar forests that have experienced severe drought in combination with grazing and logging may be in the process of shifting dominance toward more drought-tolerant species such as Q. rotundifolia.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Bruder, Andreas</style></author><author><style face="normal" font="default" size="100%">Chauvet, Eric</style></author><author><style face="normal" font="default" size="100%">Gessner, Mark O.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Litter diversity, fungal decomposers and litter decomposition under simulated stream intermittency</style></title><secondary-title><style face="normal" font="default" size="100%">Functional Ecology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">aquatic hyphomycetes</style></keyword><keyword><style  face="normal" font="default" size="100%">biodiversity and ecosystem functioning</style></keyword><keyword><style  face="normal" font="default" size="100%">decomposition</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">litter diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">litter traits</style></keyword><keyword><style  face="normal" font="default" size="100%">stream intermittency</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-2435.2011.01903.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">25</style></volume><pages><style face="normal" font="default" size="100%">1269 - 1277</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">1. The drying of stream channels resulting from flow interruption is expected to increase as a consequence of climate change. Implications for aquatic organisms and processes are profound. We assessed whether riparian diversity can partially buffer against consequences of drying on fungal decomposers and leaf litter decomposition, an important ecosystem process. 2. Our central hypothesis was that during dry periods recalcitrant leaf litter with high water-holding capacity would extend the window of opportunity for microbial activity in less recalcitrant litter when both litter types are mixed, and that this would lead to a positive litter diversity effect on decomposition. To test for such interactive effects, we conducted a diversity experiment in a Mediterranean stream, in which alder and oak litter, and a mixture of both, was subjected to various drying regimes differing in intensity and timing. 3. Drying regime affected both fungal decomposers and the decomposition rate of alder litter. Effects were observed both immediately and 3 weeks after stream flow resumed. Small differences in the timing of the dry period influenced both decomposition rate and measures of fungal performance (i.e. biomass and sporulation activity). Litter mixing, in contrast, had no effect on either decomposition or fungal decomposers, although mixing increased moisture retention in alder litter as required for the mechanism hypothesized to lead to a diversity effect. 4. Given the contrasting traits of the litter types used in the experiment, our results imply that riparian tree diversity is unlikely to buffer against increased frequencies of stream flow disruption expected in the face of climate change. It appears, however, that the precise timing of dry periods and high-flow events will strongly influence the extent to which stream food webs can exploit the resources supplied by riparian vegetation in the form of leaf litter.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">KEENAN, Trevor</style></author><author><style face="normal" font="default" size="100%">Maria Serra, JOSEP</style></author><author><style face="normal" font="default" size="100%">Lloret, Francisco</style></author><author><style face="normal" font="default" size="100%">Ninyerola, Miquel</style></author><author><style face="normal" font="default" size="100%">SABATE, Santiago</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Predicting the future of forests in the Mediterranean under climate change, with niche- and process-based models: CO2 matters!</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">6 may 2010</style></keyword><keyword><style  face="normal" font="default" size="100%">april 2010 and accepted</style></keyword><keyword><style  face="normal" font="default" size="100%">BIOMOD</style></keyword><keyword><style  face="normal" font="default" size="100%">co 2 fertilization</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 fertilization</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">gotilwa 1</style></keyword><keyword><style  face="normal" font="default" size="100%">GOTILWA+</style></keyword><keyword><style  face="normal" font="default" size="100%">niche-based models</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus sylvestris</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">received 19 january 2010</style></keyword><keyword><style  face="normal" font="default" size="100%">revised version received 27</style></keyword><keyword><style  face="normal" font="default" size="100%">Species distribution</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-2486.2010.02254.xhttp://doi.wiley.com/10.1111/j.1365-2486.2010.02254.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">565 - 579</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Assessing the potential future of current forest stands is a key to design conservation strategies and understanding potential future impacts to ecosystem service supplies. This is particularly true in the Mediterranean basin, where important future climatic changes are expected. Here, we assess and compare two commonly used modeling approaches (niche- and process-based models) to project the future of current stands of three forest species with contrasting distributions, using regionalized climate for continental Spain. Results highlight variability in model ability to estimate current distributions, and the inherent large uncertainty involved in making projections into the future. CO2 fertilization through projected increased atmospheric CO2 concentrations is shown to increase forest productivity in the mechanistic process-based model (despite increased drought stress) by up to three times that of the non-CO2 fertilization scenario by the period 2050–2080, which is in stark contrast to projections of reduced habitat suitability from the niche-based models by the same period. This highlights the importance of introducing aspects of plant biogeochemistry into current niche-based models for a realistic projection of future species distributions. We conclude that the future of current Mediterranean forest stands is highly uncertain and suggest that a new synergy between niche- and process-based models is urgently needed in order to improve our predictive ability.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">a. V. Lavoir</style></author><author><style face="normal" font="default" size="100%">Duffet, C.</style></author><author><style face="normal" font="default" size="100%">Mouillot, F.</style></author><author><style face="normal" font="default" size="100%">Rambal, S.</style></author><author><style face="normal" font="default" size="100%">Ratte, J. P.</style></author><author><style face="normal" font="default" size="100%">Schnitzler, J. P.</style></author><author><style face="normal" font="default" size="100%">Staudt, M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Scaling-up leaf monoterpene emissions from a water limited Quercus ilex woodland</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biogenic emissions</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpene</style></keyword><keyword><style  face="normal" font="default" size="100%">Volatile organic compounds (BVOC)</style></keyword><keyword><style  face="normal" font="default" size="100%">Water limitation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S1352231011001294</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">45</style></volume><pages><style face="normal" font="default" size="100%">2888 - 2897</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean ecosystems are large emitters of biogenic volatile organic compounds (BVOC), and recent studies illustrate how water stress can decrease these emissions even during hot summer. We present here a spatially explicit modelling experiment of BVOC emissions in a water-limited Mediterranean Region in Southern France dominated by Quercus ilex forests. Emission rates were estimated daily using a leaf-level emission model with appropriate up-scaling procedures. The model was based on Guenther’s empirical equations, where we inserted effects for water limitation and seasonality observed from ﬁeld measurements. Up-scaling from leaves to canopy was performed using Sellers’ theory. For each grid cell, climate variables were interpolated daily from meteorological stations. Incoming solar radiation was measured at one site and extrapolated for the all region based on slope and aspect. Soil properties were derived from pedological maps as well as a digital elevation model, while soil water content was evaluated daily using a bucket-type model. We estimated monoterpene emissions from Q. ilex woodlands to be 16 kt yr 1 (on average), with most emissions occurring in the summer. When including the water-limitation module, yearly emissions were 50% of the initial estimates, with a signiﬁcant decrease in the number of days with BVOC high emission peaks. This result highlights the importance of water control on determining air pollution peaks in Mediterranean areas and the need for scaling procedure in this area with its large range of strong emitter species.</style></abstract><issue><style face="normal" font="default" size="100%">17</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Rodriguez-Calcerrada, Jesus</style></author><author><style face="normal" font="default" size="100%">Pérez-Ramos, Ignacio M.</style></author><author><style face="normal" font="default" size="100%">OURCIVAL, JEAN-MARC</style></author><author><style face="normal" font="default" size="100%">Limousin, Jean-Marc</style></author><author><style face="normal" font="default" size="100%">Joffre, Richard</style></author><author><style face="normal" font="default" size="100%">Rambal, Serge</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Is selective thinning an adequate practice for adapting Quercus ilex coppices to climate change?</style></title><secondary-title><style face="normal" font="default" size="100%">Annals of Forest Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">forest adaptation strategy</style></keyword><keyword><style  face="normal" font="default" size="100%">seed production</style></keyword><keyword><style  face="normal" font="default" size="100%">sprouting</style></keyword><keyword><style  face="normal" font="default" size="100%">stem growth</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s13595-011-0050-x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">575 - 585</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&amp; Introduction Future climatic scenarios demand an increasing involvement of management for forest preservation, but little is known on how forestry practices will benefit stands in facing variation of climatic components. &amp; Objectives We investigated how selective thinning affected the response of an old Quercus ilex coppice to 6 years of throughfall reduction. Plots thinned from below (≈30% basal area removal) and unthinned plots were subject to either throughfall exclusion (TE; ≈33% throughfall reduction) or normal rainfall. Stem diameter growth, stem survival, and seed and sprout production were measured. &amp; Results TE did not have a significant effect on stem growth but it reduced the production of viable acorns. Also, in the absence of thinning, TE accelerated the mortality of small stems and stimulated the emergence of new sprouts. Thinning reduced stem mortality, enhanced growth of residual stems, and caused a profuse emission of resprouts. Thinning also increased total seed production, but the crop had a large proportion of aborted seeds, especially in those areas subject to TE. &amp; Conclusion The mere elimination of suppressed and diseased stems in abandoned Q. ilex coppice stands helps remaining trees to cope with current and future (probably longer and more intense) droughts. Potentially drier conditions might attenuate the success of thinning in producing a viable seed crop.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gea-Izquierdo, G.</style></author><author><style face="normal" font="default" size="100%">Cherubini, P.</style></author><author><style face="normal" font="default" size="100%">Cañellas, I.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Tree-rings reflect the impact of climate change on Quercus ilex L. along a temperature gradient in Spain over the last 100years</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">competition</style></keyword><keyword><style  face="normal" font="default" size="100%">Dendroecology</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Non-linear response</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112711004646</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">262</style></volume><pages><style face="normal" font="default" size="100%">1807 - 1816</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We analyzed tree rings over the past 100 years to understand the response of Quercus ilex L. to climate change at four different sites along a temperature gradient in a highly anthropogenically transformed ecosystem. To test the hypothesis of a climate change related decrease in productivity at warmer sites, we discuss the effect of historical management on the growth of forest stands and the spatio-temporal variability of growth in response to climate, analyzing departures from linearity in that relationship. We reconstructed stand history and investigated past growth trends using tree-rings. Then we used a dendroecological approach to study the regional, local and age-dependent response to climate, analyzing the relationship between precipitation and tree growth using non-linear mixed models. Tree rings reﬂected the origin of the studied landscape, mainly a simpliﬁcation of an original closed forest and progressive canopy opening for agrosilvopastoral purposes after the mid 1800s. As expected, trees were principally responding to water availability, and regional growth (as expressed by the ﬁrst principal component from the matrix of chronologies) was highly responsive to hydrological year precipitation (r = 0.7). In this water limited ecosystem, the response of growth to precipitation was asymptotic and independent of age, but variable in time. Maximum growth was variable at the different sites and the non-linear function of growth saturated (i.e. reached an asymptote) at temperature dependent site speciﬁc precipitation levels within the range considered in the region to lead a shift towards deciduous species dominated woodlands (around 600 mm, variable with mean temperature). Only trees at warmer sites showed symptoms of growth decline, most likely explained by water stress increase in the last decades affecting the highly transformed open (i.e. low competition) tree structure. Stands at colder locations did not show any negative growth trend and may beneﬁt from the current increase in winter temperatures. Coinciding with the decrease in productivity, trees at warmer sites responded more to moisture availability, exhibited a slower response to precipitation and reached maximum growth at higher precipitation levels than trees at colder sites. This suggests that warmer stands are threatened by climate change. The non-linear response of growth to precipitation described is meaningful for different ecological applications and provides new insights in the way trees respond to climate.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Unger, Stephan</style></author><author><style face="normal" font="default" size="100%">Máguas, Cristina</style></author><author><style face="normal" font="default" size="100%">Pereira, João S</style></author><author><style face="normal" font="default" size="100%">Aires, Luis M</style></author><author><style face="normal" font="default" size="100%">David, Teresa S</style></author><author><style face="normal" font="default" size="100%">Werner, Christiane</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Disentangling drought-induced variation in ecosystem and soil respiration using stable carbon isotopes.</style></title><secondary-title><style face="normal" font="default" size="100%">Oecologia</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Ecosystem respired carbon dioxide stable isotopic</style></keyword><keyword><style  face="normal" font="default" size="100%">Keeling plots</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystem</style></keyword><keyword><style  face="normal" font="default" size="100%">Respired carbon dioxide</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><volume><style face="normal" font="default" size="100%">163</style></volume><pages><style face="normal" font="default" size="100%">1043-1057</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Combining C flux measurements with information on their isotopic composition can yield a process-based understanding of ecosystem C dynamics. We studied the variations in both respiratory fluxes and their stable C isotopic compositions (delta(13)C) for all major components (trees, understory, roots and soil microorganisms) in a Mediterranean oak savannah during a period with increasing drought. We found large drought-induced and diurnal dynamics in isotopic compositions of soil, root and foliage respiration (delta(13)C(res)). Soil respiration was the largest contributor to ecosystem respiration (R (eco)), exhibiting a depleted isotopic signature and no marked variations with increasing drought, similar to ecosystem respired delta(13)CO(2), providing evidence for a stable C-source and minor influence of recent photosynthate from plants. Short-term and diurnal variations in delta(13)C(res) of foliage and roots (up to 8 and 4 per thousand, respectively) were in agreement with: (1) recent hypotheses on post-photosynthetic fractionation processes, (2) substrate changes with decreasing assimilation rates in combination with increased respiratory demand, and (3) decreased phosphoenolpyruvate carboxylase activity in drying roots, while altered photosynthetic discrimination was not responsible for the observed changes in delta(13)C(res). We applied a flux-based and an isotopic flux-based mass balance, yielding good agreement at the soil scale, while the isotopic mass balance at the ecosystem scale was not conserved. This was mainly caused by uncertainties in Keeling plot intercepts at the ecosystem scale due to small CO(2) gradients and large differences in delta(13)C(res) of the different component fluxes. Overall, stable isotopes provided valuable new insights into the drought-related variations of ecosystem C dynamics, encouraging future studies but also highlighting the need of improved methodology to disentangle short-term dynamics of isotopic composition of R (eco).</style></abstract><accession-num><style face="normal" font="default" size="100%">20217141</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Limousin, Jean-Marc</style></author><author><style face="normal" font="default" size="100%">Misson, Laurent</style></author><author><style face="normal" font="default" size="100%">LAVOIR, ANNE-VIOLETTE</style></author><author><style face="normal" font="default" size="100%">MARTIN, NICOLAS K.</style></author><author><style face="normal" font="default" size="100%">Rambal, Serge</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Do photosynthetic limitations of evergreen Quercus ilex leaves change with long-term increased drought severity?</style></title><secondary-title><style face="normal" font="default" size="100%">Plant, Cell &amp; Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acclimation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreen</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">photo- synthetic capacity</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis limitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasonality</style></keyword><keyword><style  face="normal" font="default" size="100%">throughfall exclusion</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-3040.2009.02112.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">863 - 875</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Seasonal drought can severely impact leaf photosynthetic capacity. This is particularly important for Mediterranean forests, where precipitation is expected to decrease as a consequence of climate change. Impacts of increased drought on the photosynthetic capacity of the evergreen Quercus ilex were studied for two years in a mature forest submitted to long-term throughfall exclusion. Gas exchange and chlorophyll fluorescence were measured on two successive leaf cohorts in a control and a dry plot. Exclusion significantly reduced leaf water potential in the dry treatment. In both treatments, light-saturated net assimilation rate (Amax), stomatal conductance (gs), maximum carboxylation rate (Vcmax), maximum rate of electron transport (Jmax), mesophyll conductance to CO2 (gm) and nitrogen investment in photosynthesis decreased markedly with soil water limitation during summer. The relationships between leaf photosynthetic parameters and leaf water potential remained identical in the two treatments. Leaf and canopy acclimation to progressive, long-term drought occurred through changes in leaf area index, leaf mass per area and leaf chemical composition, but not through modifications of physiological parameters.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Galiano, L.</style></author><author><style face="normal" font="default" size="100%">Martínez-Vilalta, J.</style></author><author><style face="normal" font="default" size="100%">Lloret, F.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought-Induced Multifactor Decline of Scots Pine in the Pyrenees and Potential Vegetation Change by the Expansion of Co-occurring Oak Species</style></title><secondary-title><style face="normal" font="default" size="100%">Ecosystems</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">canopy defoliation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">mistletoe</style></keyword><keyword><style  face="normal" font="default" size="100%">mortality</style></keyword><keyword><style  face="normal" font="default" size="100%">pinus sylvestris l</style></keyword><keyword><style  face="normal" font="default" size="100%">Recruitment</style></keyword><keyword><style  face="normal" font="default" size="100%">scots pine</style></keyword><keyword><style  face="normal" font="default" size="100%">scots pine (Pinus sylvestris L.)</style></keyword><keyword><style  face="normal" font="default" size="100%">soil properties</style></keyword><keyword><style  face="normal" font="default" size="100%">Stand Structure</style></keyword><keyword><style  face="normal" font="default" size="100%">summer</style></keyword><keyword><style  face="normal" font="default" size="100%">summer water availability</style></keyword><keyword><style  face="normal" font="default" size="100%">Water availability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/10.1007/s10021-010-9368-8http://www.springerlink.com/index/10.1007/s10021-010-9368-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">13</style></volume><pages><style face="normal" font="default" size="100%">978 - 991</style></pages><isbn><style face="normal" font="default" size="100%">1002101093</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Episodes of drought-induced tree dieback have been recently observed in many forest areas of the world, particularly at the dry edge of species distributions. Under climate change, those effects could signal potential vegetation shifts occurring over large geographical areas, with major impacts on ecosystem form and function. In this article, we studied the effect of a single drought episode, which occurred in summer 2005, on a Scots pine population in central Pyrenees (NE Spain). Our main objective was to study the environmental correlates of forest decline and vegetation change at the plot level. General and generalized linear models were used to study the relationship between canopy defoliation, mortality and recruitment, and plot characteristics. A droughtdriven multifactor dieback was observed in the study forest. Defoliation and mortality were associated with the local level of drought stress estimated at each plot. In addition, stand structure, soil properties, and mistletoe infection were also associated with the observed pattern of defoliation, presumably acting as long-term predisposing factors. Recruitment of Scots pine was low in all plots. In contrast, we observed abundant recruitment of other tree species, mostlyQuercus ilexand Q. humilis, particularly in plots where Scots pine showed high defoliation and mortality. These results suggest that an altitudinal upwards migration of Quercusspecies, mediated by the dieback of the currently dominant species, may take place in the studied slopes. Many rear-edge populations of Scots pine sheltered in the mountain environments of the Iberian Peninsula could be at risk under future climate scenarios.</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Vaz, M</style></author><author><style face="normal" font="default" size="100%">Pereira, J S</style></author><author><style face="normal" font="default" size="100%">Gazarini, L C</style></author><author><style face="normal" font="default" size="100%">David, T S</style></author><author><style face="normal" font="default" size="100%">David, J S</style></author><author><style face="normal" font="default" size="100%">Rodrigues, A</style></author><author><style face="normal" font="default" size="100%">MAROCO, J</style></author><author><style face="normal" font="default" size="100%">Chaves, M M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought-induced photosynthetic inhibition and autumn recovery in two Mediterranean oak species (Quercus ilex and Quercus suber)</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">biochemical parameters</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">Recovery</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year></dates><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">946-956</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Responses of leaf water relations and photosynthesis to summer drought and autumn rewetting were studied in two evergreen Mediterranean oak species, Quercus ilex spp. rotundifolia and Quercus suber. The predawn leaf water potential (ΨlPD), stomatal conductance (gs) and photosynthetic rate (A) at ambient conditions were measured seasonally over a 3-year period. We also measured the photosynthetic response to light and to intercellular CO2 (A/PPFD and A/Ci response curves) under water stress (summer) and after recovery due to autumn rainfall. Photosynthetic parameters, Vcmax, Jmax and triose phosphate utilization (TPU) rate, were estimated using the Farquhar model. RuBisCo activity, leaf chlorophyll, leaf nitrogen concentration and leaf carbohydrate concentration were also measured. All measurements were performed in the spring leaves of the current year. In both species, the predawn leaf water potential, stomatal conductance and photosynthetic rate peaked in spring, progressively declined throughout the summer and recovered upon autumn rainfall. During the drought period, Q. ilex maintained a higher predawn leaf water potential and stomatal conductance than Q. suber. During this period, we found that photosynthesis was not only limited by stomatal closure, but was also downregulated as a consequence of a decrease in the maximum carboxylation rate (Vcmax) and the light-saturated rate of photosynthetic electron transport (Jmax) in both species. The Vcmax and Jmax increased after the first autumnal rains and this increase was related to RuBisCo activity, leaf nitrogen concentration and chlorophyll concentration. In addition, an increase in the TPU rate and in soluble leaf sugar concentration was observed in this period. The results obtained indicate a high resilience of the photosynthetic apparatus to summer drought as well as good recovery in the following autumn rains of these evergreen oak species.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/treephys/tpq044</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/tpq044</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">KEENAN, Trevor</style></author><author><style face="normal" font="default" size="100%">Sabaté, Santi</style></author><author><style face="normal" font="default" size="100%">Gracia, Carlos</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The importance of mesophyll conductance in regulating forest ecosystem productivity during drought periods</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">16 june 2009</style></keyword><keyword><style  face="normal" font="default" size="100%">conductance limitations</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">FLUXNET</style></keyword><keyword><style  face="normal" font="default" size="100%">june 2009 and accepted</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean climate</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conduc-</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">received 12 march 2009</style></keyword><keyword><style  face="normal" font="default" size="100%">revised version received 2</style></keyword><keyword><style  face="normal" font="default" size="100%">tance</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://doi.wiley.com/10.1111/j.1365-2486.2009.02017.xhttp://dx.doi.org/10.1111/j.1365-2486.2009.02017.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">1019 - 1034</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Water availability is the most limiting factor to global plant productivity, yet photosynthetic responses to seasonal drought cycles are poorly understood, with conflicting reports on which limiting process is the most important during drought. We address the problem using a model-data synthesis approach to look at canopy level fluxes, integrating twenty years of half hour data gathered by the FLUXNET network across six Mediterranean sites. The measured canopy level, water and carbon fluxes were used, together with an inverse canopy ecophysiological model, to estimate the bulk canopy conductance, bulk mesophyll conductance, and the canopy scale carbon pools in both the intercellular spaces and at the site of carboxylation in the chloroplasts. Thus the roles of stomatal and mesophyll conductance in the regulation of internal carbon pools and photosynthesis could be separated. A quantitative limitation analysis allowed for the relative seasonal responses of stomatal, mesophyll, and biochemical limitations to be gauged. The concentration of carbon in the chloroplast was shown to be a potentially more reliable estimator of assimilation rates than the intercellular carbon concentration. Both stomatal conductance limitations and mesophyll conductance limitations were observed to regulate the response of photosynthesis to water stress in each of the six species studied. The results suggest that mesophyll conductance could bridge the gap between conflicting reports on plant responses to soil water stress, and that the inclusion of mesophyll conductance in biosphere–atmosphere transfer models may improve their performance, in particular their ability to accurately capture the response of terrestrial vegetation productivity to drought.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Díaz-Barradas, Mari Cruz</style></author><author><style face="normal" font="default" size="100%">Zunzunegui, María</style></author><author><style face="normal" font="default" size="100%">Ain-Lhout, Fatima</style></author><author><style face="normal" font="default" size="100%">Jáuregui, Juan</style></author><author><style face="normal" font="default" size="100%">Boutaleb, Said</style></author><author><style face="normal" font="default" size="100%">Álvarez-Cansino, Leonor</style></author><author><style face="normal" font="default" size="100%">Esquivias, Mari Paz</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal physiological responses of Argania spinosa tree from Mediterranean to semi-arid climate</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Browsing</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf traits</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s11104-010-0518-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">337</style></volume><pages><style face="normal" font="default" size="100%">217 - 231</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Argania spinosa (the argan tree) is a slowgrowing tree endemic of Morocco, growing on semiarid areas where no other tree species can live. With the aim of predicting temporal changes in A. spinosa woodlands under a probable increase in aridity, we set off to investigate these questions: how do A. spinosa physiological attributes respond to variations in climatic conditions and seasonality, and which is the set of attributes that most affects tree response to environmental conditions? In three study sites, Beni Snassen (North), High-Atlas (Mountain) and Admine Forest in Agadir (Coastal), gas exchange measurements, photochemical efficiency, leaf water potential and different leaf attributes were monitored in February, July and November of 2006. The Mountain site presents the most continental climate. Trees in this site were the most stressed in summer, having the lowest midday leaf water potential values, photochemical efficiency and assimilation rates. We found a Ψmd threshold around -4 MPa, below which stomatal conductance responds linearly to Ψmd . Plants from the North area never reached this threshold during the study period. Although leaf pigments presented a clear seasonal pattern, leaves from Coastal trees exhibit the highest content for each season. The three study sites were separated by two discriminate functions obtained by canonical discriminant analysis. In summer, the Mountain population is separated from the other sites mainly by assimilation rate and Fv /Fm, while in winter transpiration rates and chlorophyll content are the main discriminant variables. Our study shows that A. spinosa trees adjust their physiological status and leaf attributes to environmental conditions allowing plants to thrive under a dry climate. Under a scenario of global change, the distribution of the argan tree likely shifts to milder areas.</style></abstract><issue><style face="normal" font="default" size="100%">1-2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jiménez, Maria Dolores</style></author><author><style face="normal" font="default" size="100%">Pardos, Marta</style></author><author><style face="normal" font="default" size="100%">Puértolas, Jaime</style></author><author><style face="normal" font="default" size="100%">Kleczkowski, Leszek A</style></author><author><style face="normal" font="default" size="100%">Pardos, Jose Alberto</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Deep shade alters the acclimation response to moderate water stress in Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">Forestry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cork oak seedlings</style></keyword><keyword><style  face="normal" font="default" size="100%">deep shade</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">growth (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">light environment</style></keyword><keyword><style  face="normal" font="default" size="100%">Water availability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">82</style></volume><pages><style face="normal" font="default" size="100%">285-298</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The interactive effects of shade and drought on different morphological and physiological traits were addressed on Quercus suber L. seedlings. In our experiment, limited light treatment (1 per cent) represented the main factor constraining cork oak seedlings growth. Maximal photochemical efficiency (Fv/Fm) with light ≥15 per cent exhibited a midday fall, but under deep shade (1 per cent), Fv/Fm remained constant (&lt;0.8 values) throughout the day. The quantum efficiency of photosystem II (PSII) was lower under moderate drought only in deeply shaded plants. The drought also interacted with light through the increase of the soluble sugar content at 100 per cent light, but not under shade. Under deep shade, soluble sugar content tended to be even lower under moderate drought conditions. The chlorophyll content was not the highest under deep shade as could be expected, while the efficiency of PSII was the lowest under deep shade. We concluded that cork oak can acclimate to moderate shade (15 per cent light), but deep shade impairs some of the physiological responses to cope with low light conditions under moderate drought stress. Plants growing under deep shade were very sensitive to moderate water stress in terms of loss of carbon fixation capacity.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/forestry/cpp008 </style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/forestry/cpp008 </style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">a. -V. Lavoir</style></author><author><style face="normal" font="default" size="100%">Staudt, M.</style></author><author><style face="normal" font="default" size="100%">Schnitzler, J. P.</style></author><author><style face="normal" font="default" size="100%">Landais, D.</style></author><author><style face="normal" font="default" size="100%">Massol, F.</style></author><author><style face="normal" font="default" size="100%">Rocheteau, A.</style></author><author><style face="normal" font="default" size="100%">Rodriguez, R.</style></author><author><style face="normal" font="default" size="100%">Zimmer, I.</style></author><author><style face="normal" font="default" size="100%">Rambal, S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought reduced monoterpene emissions from the evergreen Mediterranean oak Quercus ilex: results from a throughfall displacement experiment</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeosciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BVOC emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Water availability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.biogeosciences.net/6/1167/2009/</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">1167 - 1180</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control). In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2) due to a more pronounced summer drought period in this respective year. We observed a signiﬁcant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no signiﬁcant effect on monoterpene emission was observed between normal and additional drought treatments, despite a signiﬁcant effect on leaf water potential and photochemical efﬁciency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought signiﬁcantly reduces monoterpene ﬂuxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">a.-V. Lavoir</style></author><author><style face="normal" font="default" size="100%">Staudt, M</style></author><author><style face="normal" font="default" size="100%">Schnitzler, J P</style></author><author><style face="normal" font="default" size="100%">Landais, D</style></author><author><style face="normal" font="default" size="100%">Massol, F</style></author><author><style face="normal" font="default" size="100%">Rocheteau, A</style></author><author><style face="normal" font="default" size="100%">Rodriguez, R</style></author><author><style face="normal" font="default" size="100%">Zimmer, I</style></author><author><style face="normal" font="default" size="100%">Rambal, S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Drought reduced monoterpene emissions from the evergreen Mediterranean oak Quercus ilex: results from a throughfall displacement experiment</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeosciences</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">BVOC emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Water availability</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">1167-1180</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effects of water limitations on the emission of biogenic volatile organic compounds are not well understood. Experimental approaches studying drought effects in natural conditions are still missing. To address this question, a throughfall displacement experiment was set up in a natural forest of Quercus ilex, an evergreen Mediterranean oak emitting monoterpenes. Mature trees were exposed in 2005 and 2006 either to an additional drought, to irrigation or to natural drought (untreated control). In both years, absolute monoterpene emission rates as well as the respective standard factors of the trees exposed to normal and additional drought strongly declined during the drought periods. Monoterpene emissions were lower in year 2006 than in year 2005 (factor 2) due to a more pronounced summer drought period in this respective year. We observed a signiﬁcant difference between the irrigation and additional drought or control treatment: irrigated trees emitted 82% more monoterpenes during the drought period 2006 than the trees of the other treatments. However, no signiﬁcant effect on monoterpene emission was observed between normal and additional drought treatments, despite a signiﬁcant effect on leaf water potential and photochemical efﬁciency. During the development of drought, monoterpene emissions responded exponentially rather than linearly to decreasing leaf water potential. Emissions rapidly declined when the water potential dropped below −2 MPa and photosynthesis was persistently inhibited. Monoterpene synthase activities measured in vitro showed no clear reduction during the same period. From our results we conclude that drought signiﬁcantly reduces monoterpene ﬂuxes of Mediterranean Holm oak forest into the atmosphere due to a lack of primary substrates coming from photosynthetic processes</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cotillas, Miriam</style></author><author><style face="normal" font="default" size="100%">Sabaté, Santi</style></author><author><style face="normal" font="default" size="100%">Gracia, Carlos</style></author><author><style face="normal" font="default" size="100%">Espelta, Josep Mª</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Growth response of mixed mediterranean oak coppices to rainfall reduction</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest management</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus cerrioides</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">resprouting</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112709005027</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">258</style></volume><pages><style face="normal" font="default" size="100%">1677 - 1683</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Climate change is one of the major challenges for ecosystem conservation. One of the most vulnerable areas to climate change is the Mediterranean Basin which is expected to suffer important changes in temperature and precipitation in the next few decades, leading to a warmer and dryer climate. Therefore, it is necessary to determine species-speciﬁc responses to increased drought to predict possible future changes in the structure and composition of Mediterranean forests, as well as to identify appropriate management strategies to mitigate these effects. The main aim of this study has been to experimentally simulate the effects of a 15% reduction in annual rainfall on the survival and growth of two co-occurring Mediterranean oaks with contrasting leafhabit (the evergreen Quercus ilex spp. ilex and the winter-deciduous Quercus cerrioides) and, to assess whether traditional selective thinning carried out in these mixed oak coppices (i.e. selection of one to few stems per stump) can modify the consequences of rainfall reduction. Soil moisture decreased under the rainfall reduction level while it increased in the thinned plots. Reduced rainfall did not inﬂuence tree mortality, but did lead to species-speciﬁc effects on height growth: no changes were observed in Q. ilex while height growth rate of Q. cerrioides decreased (c.a. 20%). Selective thinning improved tree growth (c.a. 50%) in stands both under natural and, and to a lesser extent, under reduced rainfall conditions. Nevertheless, the positive effects of thinning rapidly declined during our three years experiment, probably because the vigorous resprouting of thinned stumps. Our results show that the forecasted reduction in annual rainfall for the Western Mediterranean Basin can constrain the growth of some deciduous oaks in mixed oak coppices. Traditional selective thinning can increase soil moisture and encourage tree growth, thus partially mitigating this effect. However, the transient results observed in this experiment suggest the need to reconsider the intensity and the frequency of this traditional management practice in light of new climatic scenarios</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cotillas, Miriam</style></author><author><style face="normal" font="default" size="100%">Sabaté, Santi</style></author><author><style face="normal" font="default" size="100%">Gracia, Carlos</style></author><author><style face="normal" font="default" size="100%">Espelta, Josep Mª</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Growth response of mixed mediterranean oak coppices to rainfall reduction</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Forest management</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus cerrioides</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">resprouting</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">258</style></volume><pages><style face="normal" font="default" size="100%">1677-1683</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Climate change is one of the major challenges for ecosystem conservation. One of the most vulnerable areas to climate change is the Mediterranean Basin which is expected to suffer important changes in temperature and precipitation in the next few decades, leading to a warmer and dryer climate. Therefore, it is necessary to determine species-speciﬁc responses to increased drought to predict possible future changes in the structure and composition of Mediterranean forests, as well as to identify appropriate management strategies to mitigate these effects. The main aim of this study has been to experimentally simulate the effects of a 15% reduction in annual rainfall on the survival and growth of two co-occurring Mediterranean oaks with contrasting leafhabit (the evergreen Quercus ilex spp. ilex and the winter-deciduous Quercus cerrioides) and, to assess whether traditional selective thinning carried out in these mixed oak coppices (i.e. selection of one to few stems per stump) can modify the consequences of rainfall reduction. Soil moisture decreased under the rainfall reduction level while it increased in the thinned plots. Reduced rainfall did not inﬂuence tree mortality, but did lead to species-speciﬁc effects on height growth: no changes were observed in Q. ilex while height growth rate of Q. cerrioides decreased (c.a. 20%). Selective thinning improved tree growth (c.a. 50%) in stands both under natural and, and to a lesser extent, under reduced rainfall conditions. Nevertheless, the positive effects of thinning rapidly declined during our three years experiment, probably because the vigorous resprouting of thinned stumps. Our results show that the forecasted reduction in annual rainfall for the Western Mediterranean Basin can constrain the growth of some deciduous oaks in mixed oak coppices. Traditional selective thinning can increase soil moisture and encourage tree growth, thus partially mitigating this effect. However, the transient results observed in this experiment suggest the need to reconsider the intensity and the frequency of this traditional management practice in light of new climatic scenarios</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">LIMOUSIN, J. M.</style></author><author><style face="normal" font="default" size="100%">Rambal, S.</style></author><author><style face="normal" font="default" size="100%">OURCIVAL, J. M.</style></author><author><style face="normal" font="default" size="100%">Rocheteau, A.</style></author><author><style face="normal" font="default" size="100%">JOFFRE, R.</style></author><author><style face="normal" font="default" size="100%">RODRIGUEZ-CORTINA, R.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Long-term transpiration change with rainfall decline in a Mediterranean Quercus ilex forest</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">ecohydrology</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydraulic conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf area index</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf water potential</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean evergreen forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">throughfall exclusion</style></keyword><keyword><style  face="normal" font="default" size="100%">Transpiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-2486.2009.01852.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">2163 - 2175</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In the Mediterranean basin, precipitation is expected to decline as a consequence of climate change. The response of a Quercus ilex forest in southern France to such a decline in water availability was studied using a 4-year throughfall exclusion experiment. Seasonal courses of sap flow and leaf water potential were obtained from 2004 to 2007 and used to characterize tree water relations in a control and a dry treatment. The experiment reduced the average precipitation input to the soil by 29%, and resulted in a 23% reduction in annual transpiration. Soil water potential was significantly lower in the dry treatment only during summer drought, but transpiration was reduced all year round even during well-watered periods. Despite a tight stomatal control over transpiration, whole-tree hydraulic conductance was found to be lower in the trees growing in the driest conditions. This reduction in water transport capacity was observed jointly with a reduction in leaf transpiring area. Canopy leaf area decreased by 18% in the dry treatment as a consequence of the throughfall exclusion, which was found to validate the ecohydrological equilibrium theory.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Aguilera, M.</style></author><author><style face="normal" font="default" size="100%">Espinar, C.</style></author><author><style face="normal" font="default" size="100%">Ferrio, J. P.</style></author><author><style face="normal" font="default" size="100%">Pérez, G.</style></author><author><style face="normal" font="default" size="100%">Voltas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A map of autumn precipitation for the third millennium BP in the Eastern Iberian Peninsula from charcoal carbon isotopes</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geochemical Exploration</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">GIS</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron Age Cold Epoch</style></keyword><keyword><style  face="normal" font="default" size="100%">Isoscape</style></keyword><keyword><style  face="normal" font="default" size="100%">Late Holocene</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean climate</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0375674208001404</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">102</style></volume><pages><style face="normal" font="default" size="100%">157 - 165</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Carbon isotope composition (δ 13 C) in tree-rings has become routinely used in palaeoclimatic research for the assessment of changes in plant water availability in seasonally dry climates. However, the distribution of long tree-ring records around the world is very limited. Alternatively, the original climate signal of wood δ 13 C is well preserved in fossil charcoal and, accordingly, charcoal δ 13 C can be used to quantify past changes in water availability (e.g. precipitation). We report a case study on spatial palaeoclimate reconstruction which aims to characterize the transition between Bronze and Iron Ages, the so-called Iron Age Cold Epoch (ca. 900– 300 BCE), using charcoals of Quercus ilex/coccifera from a set of 11 contemporary archaeological sites of eastern Spain. Climatic inferences were obtained after calibrating a linear model predicting seasonal precipitation from δ 13 C of Q. ilex wood samples obtained across a rainfall gradient. The best regression model corresponded to September–December (autumn) precipitation (Paut ), in agreement with the fact that Q. ilex is able to exploit previous-year water reserves thanks to very effective water uptake. Subsequently, we estimated Paut from the δ 13 C of fossil charcoal to infer spatial patterns in water availability. Overall, estimated past Paut was about 19% higher (296 mm) than present-time values averaged across archaeological sites (249 mm). However, a clear geographic pattern of differences in precipitation could be observed in which the inner continental regions of eastern Spain were characterized by more humid conditions in the past, whereas the coastal strip of the Mediterranean Sea barely differed in past and present Paut values. The quite uniform distribution of archaeological sites over eastern Spain allowed development of contour maps of absolute and relative (to present) past Paut using gridded interpolation methods implemented in a GIS, highlighting the potential of this approach for reconstructing high-resolution spatial patterns of past climate</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Elsevier B.V.</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hernández, E I</style></author><author><style face="normal" font="default" size="100%">Vilagrosa, A</style></author><author><style face="normal" font="default" size="100%">Luis, V C</style></author><author><style face="normal" font="default" size="100%">Llorca, M</style></author><author><style face="normal" font="default" size="100%">Chirino, E</style></author><author><style face="normal" font="default" size="100%">Vallejo, V R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root hydraulic conductance, gas exchange and leaf water potential in seedlings of Pistacia lentiscus L. and Quercus suber L. grown under different fertilization and light regimes</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">fertilization</style></keyword><keyword><style  face="normal" font="default" size="100%">Gas exchange</style></keyword><keyword><style  face="normal" font="default" size="100%">light</style></keyword><keyword><style  face="normal" font="default" size="100%">Root hydraulic conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">67</style></volume><pages><style face="normal" font="default" size="100%">269-276</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Differences in morphology, biomass allocations and physiological responses were investigated in seedlings of Mastic tree (Pistacia lentiscus L.) and Cork oak (Quercus suber L.) submitted to contrasting fertilization and light regimes during early growth. These species are two evergreen sclerophyllous Mediterranean species frequently used in Mediterranean reforestation programmes. Fertilization was the treatment that affected most of the morphological and physiological variables evaluated in P. lentiscus and Q. suber seedlings. Leaf area and speciﬁc leaf area (SLA) were affected by shading treatment in both species, showing higher values in seedlings grown under shade. P. lentiscus seedlings showed a high capacity to modify root morphological variables and root hydraulic conductance (KR) with the fertilization treatment. In contrast, Q. suber showed low to moderate root system changes with the treatments applied, although the fertilization level affected biomass allocation (i.e., root to shoot ratio) in both species. Under high water demand, P. lentiscus seedlings with high KR allowed transpiration (E) to increase without increasing the water potential gradient between soil and leaves. In Q. suber, high fertilization induced signiﬁcant increases in photosynthesis (A), as well as a tendency to increase E with signiﬁcantly lower leaf water potential ( L)</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Goerner, A</style></author><author><style face="normal" font="default" size="100%">Reichstein, M</style></author><author><style face="normal" font="default" size="100%">Rambal, S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Estimation of Photosynthetic Light Use Efficiency in Semi-Arid Ecosystems with the MODIS-Derived Photochemical Reflectance Index</style></title><secondary-title><style face="normal" font="default" size="100%">Geoscience and Remote Sensing Symposium, 2008. IGARSS</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">light use efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical reflectance index</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><volume><style face="normal" font="default" size="100%">1</style></volume><pages><style face="normal" font="default" size="100%">756-758</style></pages><isbn><style face="normal" font="default" size="100%">9781424428083</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Direct estimations of light use efficiency from satellite data could reduce the uncertainties in data-oriented models of primary productivity. We analysed the potential of the photochemical reflectance index (PRI) based on MODIS data to approximate LUE of a Mediterranean Quercus ilex forest. Spectal band 1 (620-670 nm) turned out to be the best alternative reference band (the recommended 570 nm band does not exist on MODIS). Radiance correction with standard procedures (6S, dark object subtraction) did not improve the PRI-LUE relationship compared to the at-sensor reflectance version. The influence of surface anisotropy on the PRI signal was much reduced by constraining the observations to satellite data acquisitions with near nadir viewing angles.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wingate, Lisa</style></author><author><style face="normal" font="default" size="100%">SEIBT, ULLI</style></author><author><style face="normal" font="default" size="100%">MASEYK, KADMIEL</style></author><author><style face="normal" font="default" size="100%">OGÉE, JÉRÔME</style></author><author><style face="normal" font="default" size="100%">Almeida, Pedro</style></author><author><style face="normal" font="default" size="100%">YAKIR, D. A. N.</style></author><author><style face="normal" font="default" size="100%">Pereira, João S.</style></author><author><style face="normal" font="default" size="100%">MENCUCCINI, MAURIZIO</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evaporation and carbonic anhydrase activity recorded in oxygen isotope signatures of net CO2 fluxes from a Mediterranean soil</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">atmospheric invasion</style></keyword><keyword><style  face="normal" font="default" size="100%">carbonic anhydrase</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forests</style></keyword><keyword><style  face="normal" font="default" size="100%">oxygen isotopes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 efflux</style></keyword><keyword><style  face="normal" font="default" size="100%">soil evaporation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil water δ18O composition</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-2486.2008.01635.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">2178 - 2193</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The oxygen stable isotope composition (δ18O) of CO2 is a valuable tool for studying the gas exchange between terrestrial ecosystems and the atmosphere. In the soil, it records the isotopic signal of water pools subjected to precipitation and evaporation events. The δ18O of the surface soil net CO2 flux is dominated by the physical processes of diffusion of CO2 into and out of the soil and the chemical reactions during CO2–H2O equilibration. Catalytic reactions by the enzyme carbonic anhydrase, reducing CO2 hydration times, have been proposed recently to explain field observations of the δ18O signatures of net soil CO2 fluxes. How important these catalytic reactions are for accurately predicting large-scale biosphere fluxes and partitioning net ecosystem fluxes is currently uncertain because of the lack of field data. In this study, we determined the δ18O signatures of net soil CO2 fluxes from soil chamber measurements in a Mediterranean forest. Over the 3 days of measurements, the observed δ18O signatures of net soil CO2 fluxes became progressively enriched with a well-characterized diurnal cycle. Model simulations indicated that the δ18O signatures recorded the interplay of two effects: (1) progressive enrichment of water in the upper soil by evaporation, and (2) catalytic acceleration of the isotopic exchange between CO2 and soil water, amplifying the contributions of ‘atmospheric invasion’ to net signatures. We conclude that there is a need for better understanding of the role of enzymatic reactions, and hence soil biology, in determining the contributions of soil fluxes to oxygen isotope signals in atmospheric CO2.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Wingate, Lisa</style></author><author><style face="normal" font="default" size="100%">SEIBT, ULLI</style></author><author><style face="normal" font="default" size="100%">MASEYK, KADMIEL</style></author><author><style face="normal" font="default" size="100%">OGÉE, JÉRÔME</style></author><author><style face="normal" font="default" size="100%">Almeida, Pedro</style></author><author><style face="normal" font="default" size="100%">YAKIR, D A N</style></author><author><style face="normal" font="default" size="100%">Pereira, João S</style></author><author><style face="normal" font="default" size="100%">MENCUCCINI, MAURIZIO</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evaporation and carbonic anhydrase activity recorded in oxygen isotope signatures of net CO2 fluxes from a Mediterranean soil</style></title><secondary-title><style face="normal" font="default" size="100%">Global Change Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">atmospheric invasion</style></keyword><keyword><style  face="normal" font="default" size="100%">carbonic anhydrase</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean forests</style></keyword><keyword><style  face="normal" font="default" size="100%">oxygen isotopes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 efflux</style></keyword><keyword><style  face="normal" font="default" size="100%">soil evaporation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil water δ18O composition</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">2178-2193</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The oxygen stable isotope composition (δ18O) of CO2 is a valuable tool for studying the gas exchange between terrestrial ecosystems and the atmosphere. In the soil, it records the isotopic signal of water pools subjected to precipitation and evaporation events. The δ18O of the surface soil net CO2 flux is dominated by the physical processes of diffusion of CO2 into and out of the soil and the chemical reactions during CO2–H2O equilibration. Catalytic reactions by the enzyme carbonic anhydrase, reducing CO2 hydration times, have been proposed recently to explain field observations of the δ18O signatures of net soil CO2 fluxes. How important these catalytic reactions are for accurately predicting large-scale biosphere fluxes and partitioning net ecosystem fluxes is currently uncertain because of the lack of field data. In this study, we determined the δ18O signatures of net soil CO2 fluxes from soil chamber measurements in a Mediterranean forest. Over the 3 days of measurements, the observed δ18O signatures of net soil CO2 fluxes became progressively enriched with a well-characterized diurnal cycle. Model simulations indicated that the δ18O signatures recorded the interplay of two effects: (1) progressive enrichment of water in the upper soil by evaporation, and (2) catalytic acceleration of the isotopic exchange between CO2 and soil water, amplifying the contributions of ‘atmospheric invasion’ to net signatures. We conclude that there is a need for better understanding of the role of enzymatic reactions, and hence soil biology, in determining the contributions of soil fluxes to oxygen isotope signals in atmospheric CO2.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">La Porta, N</style></author><author><style face="normal" font="default" size="100%">Capretti, P</style></author><author><style face="normal" font="default" size="100%">Thomsen, I M</style></author><author><style face="normal" font="default" size="100%">Kasanen, R</style></author><author><style face="normal" font="default" size="100%">Hietala, A M</style></author><author><style face="normal" font="default" size="100%">Von Weissenberg, K</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Forest pathogens with higher damage potential due to climate change in Europe</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Plant Pathology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">epidemiology</style></keyword><keyword><style  face="normal" font="default" size="100%">forest diseases</style></keyword><keyword><style  face="normal" font="default" size="100%">Global change</style></keyword><keyword><style  face="normal" font="default" size="100%">Global warming</style></keyword><keyword><style  face="normal" font="default" size="100%">opportunistic fungi</style></keyword><keyword><style  face="normal" font="default" size="100%">pathogenic fungi</style></keyword><keyword><style  face="normal" font="default" size="100%">predisposition</style></keyword><keyword><style  face="normal" font="default" size="100%">review</style></keyword><keyword><style  face="normal" font="default" size="100%">Temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">Taylor &amp; Francis</style></publisher><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">177-195</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract Most atmospheric scientists agree that climate changes are going to increase the mean temperature in Europe with increased frequency of climatic extremes, such as drought, floods, and storms. Under such conditions, there is high probability that forests will be subject to increased frequency and intensity of stress due to climatic extremes. Therefore, impacts of climate change on forest health should be carefully evaluated. Given these assumptions, several fungal diseases on trees may become more devastating because of the following factors: (i) abiotic stresses, such as drought and flooding, are known to predispose trees to several pathogens; (ii) temperature and moisture affect pathogen sporulation and dispersal, and changes in climatic conditions are likely to favour certain pathogens; (iii) migration of pathogens triggered by climatic change may increase disease incidence or geographical range, when pathogens encounter new hosts and (or) new potential vectors; and (iv) new threats may appear either because of a change in tree species composition or because of invasive species. If infection success is dependent on temperature, higher mean temperatures may lead to more attacks. Pathogens that have been of importance in southern Europe may spread northward and also upward to mountains. Pathogens with evolutionary potential for greater damage should be identified to estimate the magnitude of the threat and to prepare for the changing conditions. A review of the above-mentioned cases is presented. Some priorities to improve the ability to predict impacts of climate change on tree diseases are discussed.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1080/07060661.2008.10540534</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1080/07060661.2008.10540534</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Campelo, F.</style></author><author><style face="normal" font="default" size="100%">GUTIÉRREZ, E.</style></author><author><style face="normal" font="default" size="100%">Ribas, M.</style></author><author><style face="normal" font="default" size="100%">Nabais, C.</style></author><author><style face="normal" font="default" size="100%">Freitas, H.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Relationships between climate and double rings in Quercus ilex from northeast Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chronology (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">double rings</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">growth pattern</style></keyword><keyword><style  face="normal" font="default" size="100%">growth rings</style></keyword><keyword><style  face="normal" font="default" size="100%">Precipitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1139/X07-050</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">1915 - 1923</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The influence of climatic factors on tree-ring width and the formation of double rings was studied in Quercus ilex L. growing in a coppice stand left unmanaged for 22 years. Ten trees were felled and discs were taken every 30 cm from bole and dominant branches. Dendrometer bands were installed on 10 nearby trees and the data recorded were used to confirm the accuracy of our tree-ring identification. They were also used to relate the seasonal radial growth pattern to double-ring formation. Double rings were frequent and occurred consistently along the stem. Two types of double rings could be recognized according to their width: type I, with the extra growth band accounting for approximately 50% of the tree ring; and type II, with a narrow extra growth band. Type I double rings were formed when approximately 1/2 of the growing-season precipitation occurred during the second growth period of the season and after the summer drought. Type II double rings occurred when approximately 1/3 of the precipitation in the growing season occurred after the summer drought. The formation of double rings was triggered by rainfall in summer and the extra growth-band width was related to summer and autumn environmental conditions. Double rings in Q. ilex can potentially be used in dendroclimatological studies, as they are formed in response to climatic conditions within the growing season.</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue><notes><style face="normal" font="default" size="100%">doi: 10.1139/X07-050doi: 10.1139/X07-050The following values have no corresponding Zotero field:&lt;br/&gt;publisher: NRC Research Press</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Campelo, F</style></author><author><style face="normal" font="default" size="100%">Gutiérrez, E</style></author><author><style face="normal" font="default" size="100%">Ribas, M</style></author><author><style face="normal" font="default" size="100%">Nabais, C</style></author><author><style face="normal" font="default" size="100%">Freitas, H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Relationships between climate and double rings in Quercus ilex from northeast Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chronology (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">double rings</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">growth pattern</style></keyword><keyword><style  face="normal" font="default" size="100%">growth rings</style></keyword><keyword><style  face="normal" font="default" size="100%">Precipitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><publisher><style face="normal" font="default" size="100%">NRC Research Press</style></publisher><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">1915-1923</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The influence of climatic factors on tree-ring width and the formation of double rings was studied in Quercus ilex L. growing in a coppice stand left unmanaged for 22 years. Ten trees were felled and discs were taken every 30 cm from bole and dominant branches. Dendrometer bands were installed on 10 nearby trees and the data recorded were used to confirm the accuracy of our tree-ring identification. They were also used to relate the seasonal radial growth pattern to double-ring formation. Double rings were frequent and occurred consistently along the stem. Two types of double rings could be recognized according to their width: type I, with the extra growth band accounting for approximately 50% of the tree ring; and type II, with a narrow extra growth band. Type I double rings were formed when approximately 1/2 of the growing-season precipitation occurred during the second growth period of the season and after the summer drought. Type II double rings occurred when approximately 1/3 of the precipitation in the growing season occurred after the summer drought. The formation of double rings was triggered by rainfall in summer and the extra growth-band width was related to summer and autumn environmental conditions. Double rings in Q. ilex can potentially be used in dendroclimatological studies, as they are formed in response to climatic conditions within the growing season.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1139/X07-050</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1139/X07-050</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Asensio, Dolores</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal soil and leaf CO2 exchange rates in a Mediterranean holm oak forest and their responses to drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">ATMOSPHERIC ENVIRONMENT</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar net photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">microorganisms</style></keyword><keyword><style  face="normal" font="default" size="100%">roots</style></keyword><keyword><style  face="normal" font="default" size="100%">soil CO2 exchange</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">2447 - 2455</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We measured the soil and leaf CO2 exchange in Quercus ilex and Phillyrea latfolia seasonally throughout the year in a representative site of the Mediterranean region, a natural holm oak forest growing in the Prades Mountains in southeastern Catalonia. In the wet seasons (spring and autumn), we experimentally decreased soil moisture by 30%, by excluding rainfall and water runoff in 12 plots, 1 x 10 m, and left 12 further plots as controls. Our aim was to predict the response of these gas exchanges to the drought forecasted for the next decades for this region by GCM and ecophysiological models. Annual average Soil CO2 exchange rate was 2.27 +/- 0.27 mu mol CO2 m(-2) s(-1). Annual average leaf CO2 exchange rates were 8 +/- 1 and 5 +/- 1 mu mol m(-2) s(-1) in Q. ilex and P. latfolia, respectively. Soil respiration rates in control treatments followed a seasonal pattern similar to photosynthetic activity. They reached maximum values in spring and autumn (2.5-3.8 mu mol m(-2) s(-1) soil CO2 emission rates and 7-15 mu mol m(-2) s(-1) net photosynthetic rates) and minimum values (almost 0 for both variables) in summer, showing that soil moisture was the most important factor driving the soil microbial activity and the photosynthetic activity of plants. In autumn, drought treatment strongly decreased net photosynthesis rates and stomatal conductance of Q. ilex by 44% and 53%, respectively. Soil respiration was also reduced by 43% under drought treatment in the wet seasons. In summer there were larger soil CO2 emissions in drought plots than in control plots, probably driven by autotrophic (roots) metabolism. The results indicate that leaf and Soil CO2 exchange may be strongly reduced (by ca. 44%) by the predicted decreases of soil water availability in the next decades. Long-term studies are needed to confirm these predictions or to find out possible acclimation of those processes. (c) 2006 Elsevier Ltd. All rights reserved.</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND&lt;br/&gt;publisher: PERGAMON-ELSEVIER SCIENCE LTD</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Asensio, Dolores</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal soil and leaf CO2 exchange rates in a Mediterranean holm oak forest and their responses to drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">ATMOSPHERIC ENVIRONMENT</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">foliar net photosynthetic rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">microorganisms</style></keyword><keyword><style  face="normal" font="default" size="100%">roots</style></keyword><keyword><style  face="normal" font="default" size="100%">soil CO2 exchange</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><publisher><style face="normal" font="default" size="100%">PERGAMON-ELSEVIER SCIENCE LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">2447-2455</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We measured the soil and leaf CO2 exchange in Quercus ilex and Phillyrea latfolia seasonally throughout the year in a representative site of the Mediterranean region, a natural holm oak forest growing in the Prades Mountains in southeastern Catalonia. In the wet seasons (spring and autumn), we experimentally decreased soil moisture by 30%, by excluding rainfall and water runoff in 12 plots, 1 x 10 m, and left 12 further plots as controls. Our aim was to predict the response of these gas exchanges to the drought forecasted for the next decades for this region by GCM and ecophysiological models. Annual average Soil CO2 exchange rate was 2.27 +/- 0.27 mu mol CO2 m(-2) s(-1). Annual average leaf CO2 exchange rates were 8 +/- 1 and 5 +/- 1 mu mol m(-2) s(-1) in Q. ilex and P. latfolia, respectively. Soil respiration rates in control treatments followed a seasonal pattern similar to photosynthetic activity. They reached maximum values in spring and autumn (2.5-3.8 mu mol m(-2) s(-1) soil CO2 emission rates and 7-15 mu mol m(-2) s(-1) net photosynthetic rates) and minimum values (almost 0 for both variables) in summer, showing that soil moisture was the most important factor driving the soil microbial activity and the photosynthetic activity of plants. In autumn, drought treatment strongly decreased net photosynthesis rates and stomatal conductance of Q. ilex by 44% and 53%, respectively. Soil respiration was also reduced by 43% under drought treatment in the wet seasons. In summer there were larger soil CO2 emissions in drought plots than in control plots, probably driven by autotrophic (roots) metabolism. The results indicate that leaf and Soil CO2 exchange may be strongly reduced (by ca. 44%) by the predicted decreases of soil water availability in the next decades. Long-term studies are needed to confirm these predictions or to find out possible acclimation of those processes. (c) 2006 Elsevier Ltd. All rights reserved.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">ASENSIO, D.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author><author><style face="normal" font="default" size="100%">Ogaya, R.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal soil VOC exchange rates in a Mediterranean holm oak forest and their responses to drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 flux</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil VOC exchange</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S1352231006004663</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">2456 - 2466</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Available information on soil volatile organic compound (VOC) exchange, emissions and uptake, is very scarce. We here describe the amounts and seasonality of soil VOC exchange during a year in a natural Mediterranean holm oak forest growing in Southern Catalonia. We investigated changes in soil VOC dynamics in drought conditions by decreasing the soil moisture to 30% of ambient conditions by artiﬁcially excluding rainfall and water runoff, and predicted the response of VOC exchange to the drought forecasted in the Mediterranean region for the next decades by GCM and ecophysiological models. The annual average of the total (detected) soil VOC and total monoterpene exchange rates were 3.273.2 and 0.470.3 mg m 2 h 1 , respectively, in control plots. These values represent 0.003% of the total C emitted by soil at the study site as CO2 whereas the annual mean of soil monoterpene exchange represents 0.0004% of total C. Total soil VOC exchange rates in control plots showed seasonal variations following changes in soil moisture and phenology. Maximum values were found in spring (1778 mg m 2 h 1 ). Although there was no signiﬁcant global effect of drought treatment on the total soil VOC exchange rates, annual average of total VOC exchange rates in drought plots resulted in an uptake rate (0.571.8 mg m 2 h 1 ) instead of positive net emission rates. Larger soil VOC and monoterpene exchanges were measured in drought plots than in control plots in summer, which might be mostly attributable to autotrophic (roots) metabolism. The results show that the diversity and magnitude of monoterpene and VOC soil emissions are low compared with plant emissions, that they are driven by soil moisture, that they represent a very small part of the soil-released carbon and that they may be strongly reduced or even reversed into net uptakes by the predicted decreases of soil water availability in the next decades. In all cases, it seems that VOC ﬂuxes in soil might have greater impact on soil ecology than on atmospheric chemistry</style></abstract><issue><style face="normal" font="default" size="100%">11</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Asensio, D</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author><author><style face="normal" font="default" size="100%">Ogaya, R</style></author><author><style face="normal" font="default" size="100%">Llusia, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seasonal soil VOC exchange rates in a Mediterranean holm oak forest and their responses to drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Atmospheric Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean holm oak forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Monoterpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 flux</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil VOC exchange</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">2456-2466</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Available information on soil volatile organic compound (VOC) exchange, emissions and uptake, is very scarce. We here describe the amounts and seasonality of soil VOC exchange during a year in a natural Mediterranean holm oak forest growing in Southern Catalonia. We investigated changes in soil VOC dynamics in drought conditions by decreasing the soil moisture to 30% of ambient conditions by artiﬁcially excluding rainfall and water runoff, and predicted the response of VOC exchange to the drought forecasted in the Mediterranean region for the next decades by GCM and ecophysiological models. The annual average of the total (detected) soil VOC and total monoterpene exchange rates were 3.273.2 and 0.470.3 mg m 2 h 1 , respectively, in control plots. These values represent 0.003% of the total C emitted by soil at the study site as CO2 whereas the annual mean of soil monoterpene exchange represents 0.0004% of total C. Total soil VOC exchange rates in control plots showed seasonal variations following changes in soil moisture and phenology. Maximum values were found in spring (1778 mg m 2 h 1 ). Although there was no signiﬁcant global effect of drought treatment on the total soil VOC exchange rates, annual average of total VOC exchange rates in drought plots resulted in an uptake rate (0.571.8 mg m 2 h 1 ) instead of positive net emission rates. Larger soil VOC and monoterpene exchanges were measured in drought plots than in control plots in summer, which might be mostly attributable to autotrophic (roots) metabolism. The results show that the diversity and magnitude of monoterpene and VOC soil emissions are low compared with plant emissions, that they are driven by soil moisture, that they represent a very small part of the soil-released carbon and that they may be strongly reduced or even reversed into net uptakes by the predicted decreases of soil water availability in the next decades. In all cases, it seems that VOC ﬂuxes in soil might have greater impact on soil ecology than on atmospheric chemistry</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Blanch, Josep-salvador</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sensitivity of terpene emissions to drought and fertilization in terpene-storing Pinus halepensis and non-storing Quercus ilex</style></title><secondary-title><style face="normal" font="default" size="100%">Physiologia Plantarum</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Emission rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Fertlization</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean ecosystems (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">storing and non-storing species</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">131</style></volume><pages><style face="normal" font="default" size="100%">211-225</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied the effects of water stress, fertilization and time course on foliar volatile terpene emission rates by Quercus ilex and Pinus halepensis in a garden experiment. The terpenes mostly emitted by both species were α-pinene, β-pinene, β-myrcene and Δ3-carene. P. halepensis emission rates (average 31.45 μg g−1 DM h−1) were similar to those of Q. ilex (average 31.71 μg g−1 DM h−1). The effects of drought (reduction to one-third of full watering) and fertilization (250 kg N ha−1, 250 kg P ha−1, or both) were different depending on the species: the drought treatment significantly increased the terpene emissions from Q. ilex by 33%, and the fertilization treatments reduced the terpene emissions from P. halepensis by 38%. Terpene emission rates increased with time course in parallel to raising summer temperatures in P. halepensis and Q. ilex, whose emission rates were temperature related (r = 0.42 and r = 0.68, respectively) and light related (r = 0.32 and r = 0.57, respectively). There was a positive relationship for P. halepensis, and a negative relationship for Q. ilex, between emission rates and relative water contents. No relationship was found between emission rates and N or P foliar concentrations. The results of this study show complex species-specific responses with stronger and faster short-term responses in terpene-non-storing than in storing species and indicate that terpene emissions may significantly change in the warmer, drier and more fertilized conditions predicted for the next decades in the Mediterranean region.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Blanch, Josep-salvador</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Llusia, Joan</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Sensitivity of terpene emissions to drought and fertilization in terpene-storing Pinus halepensis and non-storing Quercus ilex</style></title><secondary-title><style face="normal" font="default" size="100%">Physiologia Plantarum</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Emission rates</style></keyword><keyword><style  face="normal" font="default" size="100%">Fertlization</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean ecosystems (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Pinus halepensis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">storing and non-storing species</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1399-3054.2007.00944.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">131</style></volume><pages><style face="normal" font="default" size="100%">211 - 225</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied the effects of water stress, fertilization and time course on foliar volatile terpene emission rates by Quercus ilex and Pinus halepensis in a garden experiment. The terpenes mostly emitted by both species were α-pinene, β-pinene, β-myrcene and Δ3-carene. P. halepensis emission rates (average 31.45 μg g−1 DM h−1) were similar to those of Q. ilex (average 31.71 μg g−1 DM h−1). The effects of drought (reduction to one-third of full watering) and fertilization (250 kg N ha−1, 250 kg P ha−1, or both) were different depending on the species: the drought treatment significantly increased the terpene emissions from Q. ilex by 33%, and the fertilization treatments reduced the terpene emissions from P. halepensis by 38%. Terpene emission rates increased with time course in parallel to raising summer temperatures in P. halepensis and Q. ilex, whose emission rates were temperature related (r = 0.42 and r = 0.68, respectively) and light related (r = 0.32 and r = 0.57, respectively). There was a positive relationship for P. halepensis, and a negative relationship for Q. ilex, between emission rates and relative water contents. No relationship was found between emission rates and N or P foliar concentrations. The results of this study show complex species-specific responses with stronger and faster short-term responses in terpene-non-storing than in storing species and indicate that terpene emissions may significantly change in the warmer, drier and more fertilized conditions predicted for the next decades in the Mediterranean region.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>5</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brauch, H. G.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Kepner, W. G.</style></author><author><style face="normal" font="default" size="100%">Rubio, Jose L.</style></author><author><style face="normal" font="default" size="100%">Mouat, David A.</style></author><author><style face="normal" font="default" size="100%">Pedrazzini, Fausto</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">DESERTIFICATION–A NEW SECURITY CHALLENGE FOR THE MEDITERRANEAN? Policy agenda for recognising and coping with fatal outcomes of global</style></title><secondary-title><style face="normal" font="default" size="100%">Desertification in the Mediterranean Region. A Security …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">conflict</style></keyword><keyword><style  face="normal" font="default" size="100%">desertification</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental security</style></keyword><keyword><style  face="normal" font="default" size="100%">food security</style></keyword><keyword><style  face="normal" font="default" size="100%">Global change</style></keyword><keyword><style  face="normal" font="default" size="100%">human security</style></keyword><keyword><style  face="normal" font="default" size="100%">Land degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">migration</style></keyword><keyword><style  face="normal" font="default" size="100%">natural disasters (voyant)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2006///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/chapter/10.1007/1-4020-3760-0_02</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Springer Netherlands</style></publisher><pages><style face="normal" font="default" size="100%">11 - 85</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Desertification (representing soil degradation) is one of the three nature-induced (climate change, hydrological cycle) and of three primarily human-induced challenges (population growth, urbanisation and food) of global environmental change. These six components closely interact and contribute to fatal outcomes: primarily to extreme weather events and hydro-meteorological disasters (drought, flash floods, storms) and environmentally-induced migrations. These two fatal outcomes may have – in some cases – societal repercussions that may trigger or contribute to domestic, regional and international crisis and conflicts and thus they may become an issue of both human, societal, national and international security. To illustrate the causal linkages: for example in Morocco in the 1980s and 1990s, the following chain of events could be observed: severe drought, increase in food prices, hunger riots, general strikes, the police and armed forces interfered to repress these violent upheavals and subsequently hundreds of casualties could be deplored. These cases were not listed as a conflict in the relevant conflict data bases. The paper is organised in three parts: In the first part, the complex casual interactions among six factors of global environment change, two fatal outcomes and three societal repercussions: crises, conflicts and conflict avoidance, prevention and resolution will be discussed. In the second part, different security concepts will be reviewed that may be of relevance for dealing with desertification as a security issue. In the third part, possible security relevance pro-active political strategies will be considered, to avoid, and prevent that desertification issues can pose security challenges, and to contribute to a resolution of the desertification driven violence. 11</style></abstract><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;periodical: Desertification in the Mediterranean Region. A Security …</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>7</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brauch, H G</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">Kepner, W G</style></author><author><style face="normal" font="default" size="100%">Rubio, Jose L</style></author><author><style face="normal" font="default" size="100%">Mouat, David A</style></author><author><style face="normal" font="default" size="100%">Pedrazzini, Fausto</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">DESERTIFICATION–A NEW SECURITY CHALLENGE FOR THE MEDITERRANEAN? Policy agenda for recognising and coping with fatal outcomes of global</style></title><secondary-title><style face="normal" font="default" size="100%">Desertification in the Mediterranean Region. A Security …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">conflict</style></keyword><keyword><style  face="normal" font="default" size="100%">desertification</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">environmental security</style></keyword><keyword><style  face="normal" font="default" size="100%">food security</style></keyword><keyword><style  face="normal" font="default" size="100%">Global change</style></keyword><keyword><style  face="normal" font="default" size="100%">human security</style></keyword><keyword><style  face="normal" font="default" size="100%">Land degradation</style></keyword><keyword><style  face="normal" font="default" size="100%">migration</style></keyword><keyword><style  face="normal" font="default" size="100%">natural disasters (voyant)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><publisher><style face="normal" font="default" size="100%">Springer Netherlands</style></publisher><pages><style face="normal" font="default" size="100%">11-85</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Desertification (representing soil degradation) is one of the three nature-induced (climate change, hydrological cycle) and of three primarily human-induced challenges (population growth, urbanisation and food) of global environmental change. These six components closely interact and contribute to fatal outcomes: primarily to extreme weather events and hydro-meteorological disasters (drought, flash floods, storms) and environmentally-induced migrations. These two fatal outcomes may have – in some cases – societal repercussions that may trigger or contribute to domestic, regional and international crisis and conflicts and thus they may become an issue of both human, societal, national and international security. To illustrate the causal linkages: for example in Morocco in the 1980s and 1990s, the following chain of events could be observed: severe drought, increase in food prices, hunger riots, general strikes, the police and armed forces interfered to repress these violent upheavals and subsequently hundreds of casualties could be deplored. These cases were not listed as a conflict in the relevant conflict data bases. The paper is organised in three parts: In the first part, the complex casual interactions among six factors of global environment change, two fatal outcomes and three societal repercussions: crises, conflicts and conflict avoidance, prevention and resolution will be discussed. In the second part, different security concepts will be reviewed that may be of relevance for dealing with desertification as a security issue. In the third part, possible security relevance pro-active political strategies will be considered, to avoid, and prevent that desertification issues can pose security challenges, and to contribute to a resolution of the desertification driven violence. 11</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Jorge, I</style></author><author><style face="normal" font="default" size="100%">Navarro Cerrillo, R Mª</style></author><author><style face="normal" font="default" size="100%">Ariza, D</style></author><author><style face="normal" font="default" size="100%">Porras Tejeiro, C J</style></author><author><style face="normal" font="default" size="100%">Jorrín Novo, J V</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Aproximación proteómica para el estudio de la variabilidad genética y la respuesta a estrés en Quercus ilex L. subsp. ballota (Desf.) Samp.</style></title><secondary-title><style face="normal" font="default" size="100%">IV Congreso Forestal Español</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">proteomic</style></keyword><keyword><style  face="normal" font="default" size="100%">provenances</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><pub-location><style face="normal" font="default" size="100%">Zaragoza</style></pub-location><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Our research groups have just initiated a collaborative research project directed to studying variability among populations and responses to stresses in Quercus ilex L . by using a functional genomic approach. Our first experiments intended to analyze the leaf proteome by mean of two- dimensional gel electrophoresis for protein resolution, peptide analysis by mass spectrometry and protein identification by searching in protein or DNA databases. We have used leaves from adult trees and seedlings from different provenances. At the present we are carrying out studies of responses to water stress and pathogens. Results so far obtained and published support proteomics as an useful experimental approach in order to establish and characterize genetic variability among provenances and populations as well as to identify proteins and genes involved in responses to stresses.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Aranda, I.</style></author><author><style face="normal" font="default" size="100%">Castro, L.</style></author><author><style face="normal" font="default" size="100%">Pardos, M.</style></author><author><style face="normal" font="default" size="100%">Gil, L.</style></author><author><style face="normal" font="default" size="100%">Pardos, J. a</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of the interaction between drought and shade on water relations, gas exchange and morphological traits in cork oak (Quercus suber L.) seedlings</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">light</style></keyword><keyword><style  face="normal" font="default" size="100%">osmotic adjustment</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">water use efficiency</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S037811270500085X</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">210</style></volume><pages><style face="normal" font="default" size="100%">117 - 129</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The combined effect of drought and light on different physiological and biochemical traits was assessed in cork oak (Quercus suber L.) seedlings grown under two levels of light availability and submitted to a long-standing drought. Watering was withdrawn after germination and seedlings were allowed to dry to a water content of ca. 50% of ﬁeld capacity. At this point, water-stressed seedlings were grown under moderate drought and two light regimes: high light (HL—50%) and low light (LL— 2%). Soil water in control plants was kept close to ﬁeld capacity (90–100%) for both light environments. Water-relations parameters derived from P–V curves, gas exchange and water status at predawn (Cpd ) were evaluated at twice during the experiment. Nitrogen and chlorophyll contents were determined in the same leaves used for the gas exchange measurements. In addition, maximum rate of carboxylation (Vcmax) and electronic transport (Jmax) were derived from A–Ci curves in well-watered seedlings. The variation on moisture availability during the experiment was the same under both light environments. In control plants, Cpd was over 0.3 MPa at the two harvests, while stressed seedlings decreased to 0.9 MPa, with no differences between light treatments. Water stress decreased osmotic potentials at full (Cp100 ) and zero turgor (Cp0 ). The regressions between both potentials and Cpd showed a higher intercept in shade grown seedlings. This fact will point out the higher osmoregulation capacity in sun seedlings whatever water availability. Nitrogen investment on a per leaf mass (Nmass ), chlorophyll content (Chlmass ) and SLA tended to show a typical pattern of sun-shade acclimation. Thus, the three parameters increased with shade. Only for Nmass there was a signiﬁcant effect of watering, since water stress increased Nmass . LL plants showed a lower photosynthetic capacity in terms of maximum net photosynthesis at saturating light (Amax), which was related to a decrease in Vcmax and Jmax . Both parameters varied with speciﬁc leaf area (SLA) in a similar way. The low-light environment brought about a higher nitrogen investment in chlorophyll, while under high-light environment the investment was higher in carboxylation (Vcmax) and electronic transport ( Fmax). Stomatal conductance to water vapour (gwv ) and Amax were lower in low-light seedlings independently of watering. In addition, there was a trend to keep higher intrinsic water use efﬁciency (IWUE) under high light environment. The increase of IWUE under water stress was higher in HL seedlings. This was as consequence of the steeper decline in gwv as Cpd decreased. The decrease of Amax with Cpd occurred in a similar way in LL and HL seedlings. Thus, the HL seedlings tended to sustain a higher ability to increase IWUE than LL seedlings when they were submitted to the same water stress.</style></abstract><issue><style face="normal" font="default" size="100%">1-3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chiatante, D</style></author><author><style face="normal" font="default" size="100%">Di Iorio, A</style></author><author><style face="normal" font="default" size="100%">Scippa, G S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root responses of Quercus ilex L. seedlings to drought and fire</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">root system</style></keyword><keyword><style  face="normal" font="default" size="100%">seedlings</style></keyword><keyword><style  face="normal" font="default" size="100%">ﬁre</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Taylor &amp; Francis</style></publisher><volume><style face="normal" font="default" size="100%">139</style></volume><pages><style face="normal" font="default" size="100%">198-208</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract Drought treatments in holm-oak (Quercus ilex) seedlings induce variations in total root length, number of root apices, shoot/root dry weight, and root electrolyte leakage. When drought treatments last for more than 50 days a considerable number of fine lateral roots die, irrespective of branching order or distribution within the root system. Scorching of drought-treated seedlings induces a transient stimulation of root growth. These results indicate that root turnover is deeply affected during treatments, with survival of seedlings being entrusted to the tolerance of a number of roots situated in the deeper region of the root system. Activity of the meristematic tissue present within the apices of these surviving roots supports regeneration of above-ground lost organs during recovery. Knowledge of the mechanisms ensuring the survival of Mediterranean tree seedlings following drought and fire is useful for developing models of vegetation dynamics.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1080/11263500500160591</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1080/11263500500160591</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chiatante, D.</style></author><author><style face="normal" font="default" size="100%">Di Iorio, A.</style></author><author><style face="normal" font="default" size="100%">Scippa, G. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Root responses of Quercus ilex L. seedlings to drought and fire</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">root system</style></keyword><keyword><style  face="normal" font="default" size="100%">seedlings</style></keyword><keyword><style  face="normal" font="default" size="100%">ﬁre</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2005///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1080/11263500500160591</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">139</style></volume><pages><style face="normal" font="default" size="100%">198 - 208</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Abstract Drought treatments in holm-oak (Quercus ilex) seedlings induce variations in total root length, number of root apices, shoot/root dry weight, and root electrolyte leakage. When drought treatments last for more than 50 days a considerable number of fine lateral roots die, irrespective of branching order or distribution within the root system. Scorching of drought-treated seedlings induces a transient stimulation of root growth. These results indicate that root turnover is deeply affected during treatments, with survival of seedlings being entrusted to the tolerance of a number of roots situated in the deeper region of the root system. Activity of the meristematic tissue present within the apices of these surviving roots supports regeneration of above-ground lost organs during recovery. Knowledge of the mechanisms ensuring the survival of Mediterranean tree seedlings following drought and fire is useful for developing models of vegetation dynamics.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">doi: 10.1080/11263500500160591doi: 10.1080/11263500500160591The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Taylor &amp; Francis</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Lloret, Francisco</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author><author><style face="normal" font="default" size="100%">Ogaya, Romà</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Establishment of co-existing Mediterranean tree species under a varying soil moisture regime</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Vegetation Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean forest</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrogen use</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Recruitment</style></keyword><keyword><style  face="normal" font="default" size="100%">Regeneration</style></keyword><keyword><style  face="normal" font="default" size="100%">Seedling</style></keyword><keyword><style  face="normal" font="default" size="100%">sprouting</style></keyword><keyword><style  face="normal" font="default" size="100%">water use efficiency</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1654-1103.2004.tb02258.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">237 - 244</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated the responses of two co-existing Mediterranean trees with different regeneration strategies (Phillyrea latifolia seedlings and Quercus ilex sprouts) to experimental drought below the forest canopy. We considered different recruitment stages and used leaf isotopic discrimination to estimate water use efficiency (WUE) and nitrogen availability and use. Drought decreased the emergence and survival of seedlings and sprouts. Survival and growth of older saplings were not influenced by drought. Seedling emergence of P. latifolia was higher than Q. ilex sprout production, but Q. ilex sprouts had higher survival and growth rates. These differences disappeared in the sapling stage. Carbon isotopic discrimination suggested that Q. ilex sprouts had higher WUE than P. latifolia seedlings. Drought increased WUE of recruits, particularly in Q. ilex. Water use regulation increased with ageing, particularly in P. latifolia. Q. ilex had higher δ15N values than P. latifolia; these were also higher under drier soil conditions. Current year seedlings had higher δ15N than saplings, particularly in P. latifolia, suggesting they exploit superficial soil layers. These results suggest that sprouts obtain benefit from resources stored in parent plants. At earlier stages, they perform better than seedlings. This response is not coupled to adult vulnerability to drought for these species, revealing the difficulty of predicting species dynamics during climate change.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sardans, Jordi</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Increasing drought decreases phosphorus availability in an evergreen Mediterranean forest</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">mineralomasses</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient concentrations</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient cycles</style></keyword><keyword><style  face="normal" font="default" size="100%">phosphorus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/s11104-005-0172-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">267</style></volume><pages><style face="normal" font="default" size="100%">367 - 377</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean ecosystems are water-limited and frequently also nutrient-limited. We aimed to investigate the effects of increasing drought, as predicted by GCM and eco-physiological models for the next decades, on the P cycle and P plant availability in a Mediterranean forest. We conducted a ﬁeld experiment in a mature evergreen oak forest, establishing four drought-treatment plots and four control plots (150 m2 each). After three years, the runoff and rainfall exclusion reduced an overall 22% the soil moisture, and the runoff exclusion alone reduced it 10%. The reduction of 22% in soil moisture produced a decrease of 40% of the accumulated aboveground plant P content, above all because there was a smaller increase in aerial biomass. The plant leaf P content increased by 100 ± 40 mg m−2 in the control plots, whereas it decreased by 40 ± 40 mg m−2 in the drought plots. The soil Po-NaHCO3 (organic labile-P fraction) increased by 25% in consonance with the increase in litterfall, while the inorganic labile-P fraction decreased in relation to the organic labile-P fraction up to 48%, indicating a decrease in microbial activity. Thus, after just three years of slight drought, a clear trend towards an accumulation of P in the soil and towards a decrease of P in the stand biomass was observed. The P accumulation in the soil in the drought plots was mainly in forms that were not directly available to plants. These indirect effects of drought including the decrease in plant P availability, may</style></abstract><issue><style face="normal" font="default" size="100%">1-2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Sardans, Jordi</style></author><author><style face="normal" font="default" size="100%">Penuelas, Josep</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Increasing drought decreases phosphorus availability in an evergreen Mediterranean forest</style></title><secondary-title><style face="normal" font="default" size="100%">Plant and Soil</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">mineralomasses</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient concentrations</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient cycles</style></keyword><keyword><style  face="normal" font="default" size="100%">phosphorus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">267</style></volume><pages><style face="normal" font="default" size="100%">367-377</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean ecosystems are water-limited and frequently also nutrient-limited. We aimed to investigate the effects of increasing drought, as predicted by GCM and eco-physiological models for the next decades, on the P cycle and P plant availability in a Mediterranean forest. We conducted a ﬁeld experiment in a mature evergreen oak forest, establishing four drought-treatment plots and four control plots (150 m2 each). After three years, the runoff and rainfall exclusion reduced an overall 22% the soil moisture, and the runoff exclusion alone reduced it 10%. The reduction of 22% in soil moisture produced a decrease of 40% of the accumulated aboveground plant P content, above all because there was a smaller increase in aerial biomass. The plant leaf P content increased by 100 ± 40 mg m−2 in the control plots, whereas it decreased by 40 ± 40 mg m−2 in the drought plots. The soil Po-NaHCO3 (organic labile-P fraction) increased by 25% in consonance with the increase in litterfall, while the inorganic labile-P fraction decreased in relation to the organic labile-P fraction up to 48%, indicating a decrease in microbial activity. Thus, after just three years of slight drought, a clear trend towards an accumulation of P in the soil and towards a decrease of P in the stand biomass was observed. The P accumulation in the soil in the drought plots was mainly in forms that were not directly available to plants. These indirect effects of drought including the decrease in plant P availability, may</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Mediavilla, Sonia</style></author><author><style face="normal" font="default" size="100%">Escudero, Alfonso</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stomatal responses to drought of mature trees and seedlings of two co-occurring Mediterranean oaks</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">growth stages</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf water potential</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean quercus species</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">vapour pressure deficit</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">187</style></volume><pages><style face="normal" font="default" size="100%">281-294</style></pages><isbn><style face="normal" font="default" size="100%">3423294515</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied stomatal responses to decreasing predawn water potential (Cpd ) and increasing leaf-to-air water vapour pressure deﬁcit (VPD) of seedlings and mature trees of two co-occurring Mediterranean oaks with contrasting leaf habits: the evergreen Quercus rotundifolia and the deciduous Quercus faginea. Our objective was to deﬁne and to compare the stomatal strategies of both speciesfordroughtresistanceandtoidentifythepossibledifferencesbetweengrowthstagesinselecteddroughtadaptationattributes. Among the mature trees, Q. rotundifolia exhibited a water-use behaviour that was more conservative than that of Q. faginea: lower maximum stomatal conductances and greater sensitivity to VPD than the deciduous species. As a result, the leaf water potential of the evergreen species never decreased along the day and along the growth season as much as in the deciduous species; this may help to guarantee longer leaf longevity by avoiding irreversible damage during the summer drought. The seedlings of the two species showed a less conservative water-use strategy in comparison with adult trees: a relatively high stomatal conductance and lower stomatal sensitivity to soil and atmospheric drought. As a consequence, leaf water potential decreased more in the seedlings along the day than in the adults. Q. rotundifolia was the species for which the most pronounced differences between growth stages were obtained. Thus, interspeciﬁc differences in response to drought disappeared in the ﬁrst stages of the life of the trees, and the seedlings of the two species showed a common strategy, probably as a response to the competition from the herbaceous layer. A low stomatal sensitivity in beneﬁt of an increase in growth would probably be a more successful strategy under the competitive conditions that seedlings experience during their establishment.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Mediavilla, Sonia</style></author><author><style face="normal" font="default" size="100%">Escudero, Alfonso</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stomatal responses to drought of mature trees and seedlings of two co-occurring Mediterranean oaks</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Ecology and Management</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">growth stages</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf water potential</style></keyword><keyword><style  face="normal" font="default" size="100%">mediterranean quercus species</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">vapour pressure deficit</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0378112703003827</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">187</style></volume><pages><style face="normal" font="default" size="100%">281 - 294</style></pages><isbn><style face="normal" font="default" size="100%">3423294515</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We studied stomatal responses to decreasing predawn water potential (Cpd ) and increasing leaf-to-air water vapour pressure deﬁcit (VPD) of seedlings and mature trees of two co-occurring Mediterranean oaks with contrasting leaf habits: the evergreen Quercus rotundifolia and the deciduous Quercus faginea. Our objective was to deﬁne and to compare the stomatal strategies of both speciesfordroughtresistanceandtoidentifythepossibledifferencesbetweengrowthstagesinselecteddroughtadaptationattributes. Among the mature trees, Q. rotundifolia exhibited a water-use behaviour that was more conservative than that of Q. faginea: lower maximum stomatal conductances and greater sensitivity to VPD than the deciduous species. As a result, the leaf water potential of the evergreen species never decreased along the day and along the growth season as much as in the deciduous species; this may help to guarantee longer leaf longevity by avoiding irreversible damage during the summer drought. The seedlings of the two species showed a less conservative water-use strategy in comparison with adult trees: a relatively high stomatal conductance and lower stomatal sensitivity to soil and atmospheric drought. As a consequence, leaf water potential decreased more in the seedlings along the day than in the adults. Q. rotundifolia was the species for which the most pronounced differences between growth stages were obtained. Thus, interspeciﬁc differences in response to drought disappeared in the ﬁrst stages of the life of the trees, and the seedlings of the two species showed a common strategy, probably as a response to the competition from the herbaceous layer. A low stomatal sensitivity in beneﬁt of an increase in growth would probably be a more successful strategy under the competitive conditions that seedlings experience during their establishment.</style></abstract><issue><style face="normal" font="default" size="100%">2-3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hódar, José a.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Leaf fluctuating asymmetry of Holm oak in response to drought under contrasting climatic conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Arid Environments</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Fluctuating asymmetry</style></keyword><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean climate</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">RAINFALL</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><volume><style face="normal" font="default" size="100%">52</style></volume><pages><style face="normal" font="default" size="100%">233-243</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Fluctuating asymmetry (FA) can be defined as small, random deviations from bilateral symmetry in structures that, typically, are bilaterally symmetrical. In plants, FA has been used as a tool for monitoring levels of ecological stress. In this work, I analyse the FA response to drought in the Holm oak (Quercus ilex) in SE Spain, to test whether FA increases or diminishes when climatic conditions are more stressful. Leaves from three different cohorts, corresponding to one drought year (1995) and two wet years (1996 and 1997) were collected at five sites contrasting in rainfall conditions, from very low to rather high rainfall. In two of the zones, two different morphs of leaves were collected. Furthermore, one of the sites was chosen close to a river, to examine the effect of water enhancement in the trees during drought and post-drought conditions. The results revealed no differences in response to drought in terms of FA between leaf morphs. However, while plants from rainy sites showed a decline in leaf FA from drought to wet years, the water-enhanced site and the dry sites showed scant or negligible differences between years. There was a significant decrease in FA from rainy sites to dry sites. These results suggest that (1) plants living in the more stressful sites are more symmetrical, (2) the more symmetrical plants respond less to yearly variations in drought stress, and (3) the response to yearly variations in drought depend on the climatic conditions in which a tree is living</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Gulías, J</style></author><author><style face="normal" font="default" size="100%">Flexas, J</style></author><author><style face="normal" font="default" size="100%">Abadía, A</style></author><author><style face="normal" font="default" size="100%">Madrano, H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Photosynthetic responses to water deficit in six Mediterranean sclerophyll species: possible factors explaining the declining distribution of Rhamnus ludovici-salvatoris, an endemic Balearic species.</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">deciduous</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">evergreen</style></keyword><keyword><style  face="normal" font="default" size="100%">Gas exchange</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf mass area</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">Pistacia</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus</style></keyword><keyword><style  face="normal" font="default" size="100%">Rhamnus</style></keyword><keyword><style  face="normal" font="default" size="100%">xanthophyll cycle</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year></dates><publisher><style face="normal" font="default" size="100%">Oxford University Press / USA</style></publisher><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">687-697</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We sought to explain the declining distribution in the Balearic Islands of the endemic shrub Rhamnus ludovici-salvatoris R. Chodat, by comparing its photosynthetic response to drought with that of several widely distributed, competing Mediterranean species (R. alaternus L., Quercus ilex L., Pistacia lentiscus L., Q. humilis Mill. and P. terebinthus L.). [ABSTRACT FROM PUBLISHER]</style></abstract><notes><style face="normal" font="default" size="100%">Accession Number: 51808417; Gulías, J. 1 Flexas, J. 1 Abadía, A. 2; Email Address: dbajfs4@ps.uib.es Madrano, H. 1; Affiliation: 1: Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears Carretera de Valldemossa, Km. 7.5, 07071 Palma de Mallorca, Balears, Spain 2: Departamento de Nutriciön Vegetal, Estaciön Experimental de Aula Dei (Consejo Superior de Investigaciones Científicas) Apartado 202, 50080 Zaragoza, Aragön, Spain; Source Info: Jul2002, Vol. 22 Issue 10, p687; Subject Term: BUCKTHORNS; Subject Term: PLANT-water relationships; Subject Term: PHOTOSYNTHESIS; Subject Term: PLANT physiology; Subject Term: BALEARIC Islands (Spain); Subject Term: SPAIN; Author-Supplied Keyword: chlorophyll fluorescence; Author-Supplied Keyword: deciduous; Author-Supplied Keyword: drought; Author-Supplied Keyword: evergreen; Author-Supplied Keyword: gas exchange; Author-Supplied Keyword: leaf mass area; Author-Supplied Keyword: nitrogen; Author-Supplied Keyword: Pistacia; Author-Supplied Keyword: Pistacia Quercus; Author-Supplied Keyword: Quercus; Author-Supplied Keyword: Rhamnus; Author-Supplied Keyword: xanthophyll cycle; Number of Pages: 11p; Illustrations: 2 Charts, 2 Graphs; Document Type: Article</style></notes><research-notes><style face="normal" font="default" size="100%">Accession Number: 51808417; Gulías, J. 1 Flexas, J. 1 Abadía, A. 2; Email Address: dbajfs4@ps.uib.es Madrano, H. 1; Affiliation: 1: Laboratori de Fisiologia Vegetal, Departament de Biologia, Universitat de les Illes Balears Carretera de Valldemossa, Km. 7.5, 07071 Palma de Mallorca, Balears, Spain 2: Departamento de Nutriciön Vegetal, Estaciön Experimental de Aula Dei (Consejo Superior de Investigaciones Científicas) Apartado 202, 50080 Zaragoza, Aragön, Spain; Source Info: Jul2002, Vol. 22 Issue 10, p687; Subject Term: BUCKTHORNS; Subject Term: PLANT-water relationships; Subject Term: PHOTOSYNTHESIS; Subject Term: PLANT physiology; Subject Term: BALEARIC Islands (Spain); Subject Term: SPAIN; Author-Supplied Keyword: chlorophyll fluorescence; Author-Supplied Keyword: deciduous; Author-Supplied Keyword: drought; Author-Supplied Keyword: evergreen; Author-Supplied Keyword: gas exchange; Author-Supplied Keyword: leaf mass area; Author-Supplied Keyword: nitrogen; Author-Supplied Keyword: Pistacia; Author-Supplied Keyword: Pistacia Quercus; Author-Supplied Keyword: Quercus; Author-Supplied Keyword: Rhamnus; Author-Supplied Keyword: xanthophyll cycle; Number of Pages: 11p; Illustrations: 2 Charts, 2 Graphs; Document Type: Article</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Leeuwen, E. P. Van</style></author><author><style face="normal" font="default" size="100%">Hendriks, KCMA</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of environmental stress on forest crown condition in Europe. Part II: Estimation of stress induced by meteorology and air pollutants</style></title><secondary-title><style face="normal" font="default" size="100%">Water, Air, &amp; Soil Pollution</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acidity</style></keyword><keyword><style  face="normal" font="default" size="100%">air pollution</style></keyword><keyword><style  face="normal" font="default" size="100%">ammonia</style></keyword><keyword><style  face="normal" font="default" size="100%">atmospheric deposition</style></keyword><keyword><style  face="normal" font="default" size="100%">Base cations</style></keyword><keyword><style  face="normal" font="default" size="100%">deposition model</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen oxides</style></keyword><keyword><style  face="normal" font="default" size="100%">Ozone</style></keyword><keyword><style  face="normal" font="default" size="100%">sulphur</style></keyword><keyword><style  face="normal" font="default" size="100%">temperature stress</style></keyword><keyword><style  face="normal" font="default" size="100%">water balance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2000///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/U4GG79415253037M.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">119</style></volume><pages><style face="normal" font="default" size="100%">335 - 362</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">In order to assess the relationship between environmental stress and crown condition of forest trees monitored since 1986 in Europe, estimates of stress factors, including temperature stress, drought stress and air pollution stress, were derived with the best data, methods and models currently available. This paper presents information on the methods used to derive such stress factors, and on the overall ranges, the temporal trends, the spatial distribution and the reliability of the calculated stress factors. The temperature stress indices did not show much temporal variation between 1985 to 1995. As expected spatial patterns were north-south orientated, going from colder northern regions to warmer southern regions. The calculated relative transpiration showed a more complex pattern, coinciding to a large extend with patterns of rainfall and temperature. Potential acid deposition decreased between 1986 and 1992, but remained fairly constant after 1992. The strong decrease was mainly the result of the decrease in SOx deposition, and to a small decrease in NOy deposition. Highest levels of the S and N deposition were calculated in Central and Western Europe. Base cation deposition was largest in coastal areas and in southern Europe. This is mainly due to soil dust, Sahara dust and sea salt. Base cation deposition can compensate almost entirely for the potential inputs in the south of Europe, whereas in central Europe it equalled about 25% of the potential acid input. A comparison between site speciﬁc modelled deposition and deposition derived from throughfall data showed that the total acid deposition is usually overestimated by the model, whereas the total nitrogen deposition is underestimated, especially at plots with high nitrogen loads. There is, however, a signiﬁcant correlation between measured and modelled data for all S and N deposition, thus allowing their use in a statistical analyses.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Infante, J M</style></author><author><style face="normal" font="default" size="100%">Damesin, C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Modelling leaf gas exchange in holm-oak trees in southern Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon dioxide assimilation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf gas exchange</style></keyword><keyword><style  face="normal" font="default" size="100%">oak savannah</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis model</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><volume><style face="normal" font="default" size="100%">95</style></volume><pages><style face="normal" font="default" size="100%">203-223</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">This paper presents a mechanistically based C3 leaf CO2 assimilation model linked with an empirical stomatal model to simulate Quercus ilex leaf net photosynthesis and transpiration in oak-savannah ecosystems of southern Spain. The model estimates (time integration) daily and seasonal changes in carbon ®xation, transpiration, and water use ef®ciency of a single leaf in free air. Simulations were carried out on two trees for a dry year. Results shown in our study demonstrate that the modelling approach, compared to ®eld measurements, provides a realistic description of diurnal and seasonal patterns of leaf gas-exchange response to different environmental conditions, and as affected by water availability</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Infante, J. M.</style></author><author><style face="normal" font="default" size="100%">Damesin, C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Modelling leaf gas exchange in holm-oak trees in southern Spain</style></title><secondary-title><style face="normal" font="default" size="100%">Agricultural and Forest …</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon dioxide assimilation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">leaf gas exchange</style></keyword><keyword><style  face="normal" font="default" size="100%">oak savannah</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis model</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0168192399000337</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">95</style></volume><pages><style face="normal" font="default" size="100%">203 - 223</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">This paper presents a mechanistically based C3 leaf CO2 assimilation model linked with an empirical stomatal model to simulate Quercus ilex leaf net photosynthesis and transpiration in oak-savannah ecosystems of southern Spain. The model estimates (time integration) daily and seasonal changes in carbon ®xation, transpiration, and water use ef®ciency of a single leaf in free air. Simulations were carried out on two trees for a dry year. Results shown in our study demonstrate that the modelling approach, compared to ®eld measurements, provides a realistic description of diurnal and seasonal patterns of leaf gas-exchange response to different environmental conditions, and as affected by water availability</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Schwanz, P</style></author><author><style face="normal" font="default" size="100%">Polle, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Antioxidative systems, pigment and protein contents in leaves of adult mediterranean oak species (Quercus pubescens and Q. ilex) with lifetime exposure to elevated CO2</style></title><secondary-title><style face="normal" font="default" size="100%">New Phytologist</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">antioxidants</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon dioxide enrichment</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidative stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus spp. (holm oak - white oak)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">Cambridge University Press</style></publisher><volume><style face="normal" font="default" size="100%">140</style></volume><pages><style face="normal" font="default" size="100%">411-423</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The aim of the present study was to investigate the effects of elevated CO2 on the antioxidative systems and the contents of pigments, soluble protein and lipid peroxidation in leaves of adult oaks, Quercus pubescens and Quercus ilex, grown at naturally enriched CO2 concentrations. For this purpose, a field study was conducted at two CO2 springs in Central Italy. Measurements of the pre-dawn water potentials indicated less drought stress in trees close to CO2 springs than in those grown at ambient CO2 concentrations. Most leaf constituents investigated showed significant variability between sampling dates, species and sites. The foliar contents of protein and chlorophylls were not affected in trees grown close to the CO2 vents compared with those in ambient conditions. Increases in glutathione and other soluble thiols were observed, but these responses might have been caused by a low pollution of the vents with sulphurous gases. At CO2 vents, glutathione reductase was unaffected, and superoxide dismutase activity was significantly diminished, in both species. Generally, the activities of catalase, guaiacol peroxidase and ascorbate peroxidase as well as the sum of dehydroascorbate and ascorbate were decreased in leaves from trees grown in naturally CO2-enriched environments compared with those grown at ambient CO2 concentrations. The reduction in protective enzymes did not result in increased lipid peroxidation, but increased monodehydroascorbate radical reductase and dehydroascorbate reductase activities found in leaves of Q. pubescens suggest that the smaller pool of ascorbate was subjected to higher turnover rates. These data show that changes in leaf physiology persist, even after lifetime exposure to enhanced atmospheric CO2. The results suggest that the down-regulation of protective systems, which has also previously been found in young trees or seedlings under controlled exposure to elevated CO2 concentrations, might reflect a realistic response of antioxidative defences in mature trees in a future high-CO2 world.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in terpene content and emission in potted Mediterranean woody plants under severe drought</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean conditions</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Terpene emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Woody plants</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">NRC Research Press</style></publisher><volume><style face="normal" font="default" size="100%">76</style></volume><pages><style face="normal" font="default" size="100%">1366-1373</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Terpene concentration and emission were studied in potted plants of some of the most common Mediterranean woody species (Pinus halepensis L., Pistacia lentiscus L., Cistus albidus L., Cistus monspeliensis L., Quercus ilex L., Quercus coccifera L., Phillyrea latifolia L., Phillyrea angustifolia L., and Arbutus unedo L.) under irrigation and under severe drought conditions that dropped relative water content to a range between 40% in Q. ilex and 85% in Phillyrea latifolia after withholding watering for one dry summer week. Terpene concentrations were detected in Pinus halepensis, Pistacia lentiscus, C. albidus, and C. monspeliensis, and they increased after withholding watering except in C. albidus. Terpene emission was detected in all species except Phillyrea angustifolia and A. unedo. Pinus halepensis showed the highest diurnal terpene emission rates of 86 µg·g-1 dry wt.·h-1 followed by C. albidus, Pistacia lentiscus, Q. ilex, Q. coccifera, Phillyrea latifolia, and C. monspeliensis (4 µg·g-1 dry wt.·h-1). Emitted terpenes represented from 0.33% of C fixed in C. monspeliensis to 10% in C. albidus. All species severely decreased their terpene emission rates under severe drought conditions. Emission by terpene-storing species (e.g., Pinus halepensis) was more related to temperature than in nonstoring species (e.g., Q. ilex), which showed emission relationships with photosynthetic rates. The monoterpenes alpha-pinene, beta-pinene, beta-phellandrene, and limonene and the sesquiterpene caryophyllene were the most abundant terpenes stored and emitted by these Mediterranean plant species.Key words: drought, Mediterranean conditions, terpene concentration, terpene emission, woody plants</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1139/b98-141</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1139/b98-141</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Changes in terpene content and emission in potted Mediterranean woody plants under severe drought</style></title><secondary-title><style face="normal" font="default" size="100%">Canadian Journal of Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean conditions</style></keyword><keyword><style  face="normal" font="default" size="100%">terpene concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Terpene emission</style></keyword><keyword><style  face="normal" font="default" size="100%">Woody plants</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1139/b98-141</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">76</style></volume><pages><style face="normal" font="default" size="100%">1366 - 1373</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Terpene concentration and emission were studied in potted plants of some of the most common Mediterranean woody species (Pinus halepensis L., Pistacia lentiscus L., Cistus albidus L., Cistus monspeliensis L., Quercus ilex L., Quercus coccifera L., Phillyrea latifolia L., Phillyrea angustifolia L., and Arbutus unedo L.) under irrigation and under severe drought conditions that dropped relative water content to a range between 40% in Q. ilex and 85% in Phillyrea latifolia after withholding watering for one dry summer week. Terpene concentrations were detected in Pinus halepensis, Pistacia lentiscus, C. albidus, and C. monspeliensis, and they increased after withholding watering except in C. albidus. Terpene emission was detected in all species except Phillyrea angustifolia and A. unedo. Pinus halepensis showed the highest diurnal terpene emission rates of 86 µg·g-1 dry wt.·h-1 followed by C. albidus, Pistacia lentiscus, Q. ilex, Q. coccifera, Phillyrea latifolia, and C. monspeliensis (4 µg·g-1 dry wt.·h-1). Emitted terpenes represented from 0.33% of C fixed in C. monspeliensis to 10% in C. albidus. All species severely decreased their terpene emission rates under severe drought conditions. Emission by terpene-storing species (e.g., Pinus halepensis) was more related to temperature than in nonstoring species (e.g., Q. ilex), which showed emission relationships with photosynthetic rates. The monoterpenes alpha-pinene, beta-pinene, beta-phellandrene, and limonene and the sesquiterpene caryophyllene were the most abundant terpenes stored and emitted by these Mediterranean plant species.Key words: drought, Mediterranean conditions, terpene concentration, terpene emission, woody plants</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><notes><style face="normal" font="default" size="100%">doi: 10.1139/b98-141doi: 10.1139/b98-141The following values have no corresponding Zotero field:&lt;br/&gt;publisher: NRC Research Press</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Ksontini, Mustapha</style></author><author><style face="normal" font="default" size="100%">Louguet, Philippe</style></author><author><style face="normal" font="default" size="100%">Laffray, Daniel</style></author><author><style face="normal" font="default" size="100%">Rejeb Nejib, Mohamed</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Comparaison des effets de la contrainte hydrique sur la croissance, la conductance stomatique et la photosynthèse de jeunes plants de chênes méditerranéens (Quercus suber, Q. faginea, Q. coccifera) en Tunisie</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus coccifera</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus faginea</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">477-495</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Comparison of the water stress effects on stomatal conductance, photosynthesis and growth of Mediterannean oak seedlings (Quercus suber L., Q. faginea, Q. coccifera) in Tunisia. Two evergreen oaks (Quercus suber L., Q. coccifera) and one deciduous oak (Q. faginea Willd.) were subjected to drought in a nursery in Tunis. Six- and 18-month-old seedlings were grown in pots and underwent two cycles of drought by withholding water supply. Predawn and midday leaf water potentials, stomatal conductance, photosynthesis and plant transpiration were recorded. An analysis of root and shoot biomass, shoot-to-root ratio and leaf area was also performed. Our results showed a higher reduction of shoot-to-root biomass ratio of Q. faginea compared to Q. coccifera under water limitation. The stomatal conductance decrease, related to the decrease of predawn leaf water potential, occurred earlier with Q. faginea. Q. coccifera kept its stomata partly open at a water potential of -3.0 MPa. Q. suber behaved somewhat intermediate. Photosynthesis and stomatal conductance were correlated and showed a midday depression. Our results indicate that more ecophysiological studies are required to take into account seedling and leaf ages during the juvenile stage for a better understanding of the water stress responses of these species and regeneration problems of oaks.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Filella, I.</style></author><author><style face="normal" font="default" size="100%">Llusia, J.</style></author><author><style face="normal" font="default" size="100%">Piñol, J.</style></author><author><style face="normal" font="default" size="100%">Penuelas, J.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Leaf gas exchange and ﬂuorescence of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex saplings in severe drought and high temperature conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hF/F’m</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Pistacia lentiscus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">213 - 220</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Saplings of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex were witheld watering for 7 days, followed by reirrigation. Incident photosynthetic photon ﬂux density (PPFD), leaf temperature, net photosynthetic rates, stomatal conductance, and photochemical efﬁciency of the photosystem II (DF:F’m) were measured three times during the day. The watered plants had higher photosynthetic rates, stomatal conductances, DF:F’m and ETR than non-watered plants. However, watered plants were mildly water stressed as shown by low ratio of variable to maximal ﬂuorescence (Fv:Fm) and high non-photochemical ﬂuorescence quenching (qN). Their DF:F%m was low in the morning and increased in the evening, following the variations in PPFD. Watered plants of Q. ilex had lower photosynthetic activity, stomatal conductance and photosynthetic radiation use efﬁciency than Ph. latifolia and P. lentiscus, and, conversely, reached the highest DF:F%m and ETR. This seems to indicate a different relationship between photosynthetic activity and electron transport rate in Q. ilex compared to the other two species. Ph. latifolia and P. lentiscus appeared to be better adapted to severe drought than Q. ilex.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Filella, I</style></author><author><style face="normal" font="default" size="100%">Llusia, J</style></author><author><style face="normal" font="default" size="100%">Piñol, J</style></author><author><style face="normal" font="default" size="100%">Penuelas, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Leaf gas exchange and ﬂuorescence of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex saplings in severe drought and high temperature conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental and Experimental Botany</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hF/F’m</style></keyword><keyword><style  face="normal" font="default" size="100%">phillyrea latifolia</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthetic rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Pistacia lentiscus</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">213-220</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Saplings of Phillyrea latifolia, Pistacia lentiscus and Quercus ilex were witheld watering for 7 days, followed by reirrigation. Incident photosynthetic photon ﬂux density (PPFD), leaf temperature, net photosynthetic rates, stomatal conductance, and photochemical efﬁciency of the photosystem II (DF:F’m) were measured three times during the day. The watered plants had higher photosynthetic rates, stomatal conductances, DF:F’m and ETR than non-watered plants. However, watered plants were mildly water stressed as shown by low ratio of variable to maximal ﬂuorescence (Fv:Fm) and high non-photochemical ﬂuorescence quenching (qN). Their DF:F%m was low in the morning and increased in the evening, following the variations in PPFD. Watered plants of Q. ilex had lower photosynthetic activity, stomatal conductance and photosynthetic radiation use efﬁciency than Ph. latifolia and P. lentiscus, and, conversely, reached the highest DF:F%m and ETR. This seems to indicate a different relationship between photosynthetic activity and electron transport rate in Q. ilex compared to the other two species. Ph. latifolia and P. lentiscus appeared to be better adapted to severe drought than Q. ilex.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cerdà, A.</style></author><author><style face="normal" font="default" size="100%">Schnabel, S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil hydrological response under simulated rainfall in the Dehesa land system (Extremadura, SW Spain) under drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Earth Surface Processes and Landforms</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrophobicity</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil hydrology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1096-9837(199803)23:3&lt;195::AID-ESP830&gt;3.0.CO;2-I/abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">195 - 209</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil hydrology was investigated in the Guadelperalón experimental watershed in order to determine the inﬂuence of land use and vegetation cover on runoff and inﬁltration within the Dehesa land system. Five soil–vegetation units were selected: (1) tree cover, (2) sheep trials, (3) shrub cover, (4) hillslope grass and (5) bottom grass. The results of the simulated rainfall experiments performed at an intensity of 53·6mm h −1 during one hour on plots of 0·25m 2 , and the water drop penetration time test indicate the importance of water repellency in the Dehesa land system under drought conditions. Low inﬁltration rates (c. 9–44mm h −1 ) were found everywhere except at shrub sites and in areas with low grazing pressure. Soil water repellency greatly reduced inﬁltration, especially beneath Quercus ilex canopies, where fast ponding and greater runoff rates were observed. The low vegetation cover as a consequence of a prolonged drought and grazing pressure, in conjunction with the soil water repellency, induces high runoff rates (15–70 per cent). In spite of this, macropore ﬂuxes were found in different locations, beneath trees, on shrub-covered surfaces, as well as at sites with a dominance of herbaceous cover. Discontinuity of the runoff ﬂuxes due to variations in hydrophobicity causes preferential ﬂows and as a consequence deeper inﬁltration, especially where macropores are developed</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cerdá, A</style></author><author><style face="normal" font="default" size="100%">Schnabel, S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil hydrological response under simulated rainfall in the Dehesa land system (Extremadura, SW Spain) under drought conditions</style></title><secondary-title><style face="normal" font="default" size="100%">Earth Surface Processes and Landforms</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Dehesa</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">hydrophobicity</style></keyword><keyword><style  face="normal" font="default" size="100%">rainfall simulation</style></keyword><keyword><style  face="normal" font="default" size="100%">soil hydrology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">23</style></volume><pages><style face="normal" font="default" size="100%">195-209</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil hydrology was investigated in the Guadelperalón experimental watershed in order to determine the inﬂuence of land use and vegetation cover on runoff and inﬁltration within the Dehesa land system. Five soil–vegetation units were selected: (1) tree cover, (2) sheep trials, (3) shrub cover, (4) hillslope grass and (5) bottom grass. The results of the simulated rainfall experiments performed at an intensity of 53·6mm h −1 during one hour on plots of 0·25m 2 , and the water drop penetration time test indicate the importance of water repellency in the Dehesa land system under drought conditions. Low inﬁltration rates (c. 9–44mm h −1 ) were found everywhere except at shrub sites and in areas with low grazing pressure. Soil water repellency greatly reduced inﬁltration, especially beneath Quercus ilex canopies, where fast ponding and greater runoff rates were observed. The low vegetation cover as a consequence of a prolonged drought and grazing pressure, in conjunction with the soil water repellency, induces high runoff rates (15–70 per cent). In spite of this, macropore ﬂuxes were found in different locations, beneath trees, on shrub-covered surfaces, as well as at sites with a dominance of herbaceous cover. Discontinuity of the runoff ﬂuxes due to variations in hydrophobicity causes preferential ﬂows and as a consequence deeper inﬁltration, especially where macropores are developed</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tognetti, R</style></author><author><style face="normal" font="default" size="100%">Longobucco, A</style></author><author><style face="normal" font="default" size="100%">Miglietta, F</style></author><author><style face="normal" font="default" size="100%">Raschi, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Transpiration and stomatal behaviour of Quercus ilex plants during the summer in a Mediterranean carbon dioxide spring</style></title><secondary-title><style face="normal" font="default" size="100%">Plant, Cell &amp; Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">natural CO2 springs</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Science Ltd, UK</style></publisher><volume><style face="normal" font="default" size="100%">21</style></volume><pages><style face="normal" font="default" size="100%">613-622</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Variations in the water relations and stomatal response of Quercus ilex were analysed under field conditions by comparing trees at two locations in a Mediterranean environment during two consecutive summers (1993 and 1994). We used the heat-pulse velocity technique to estimate transpirational water use of trees during a 5 month period from June to November 1994. At the end of sap flow measurements, the trees were harvested, and the foliage and sapwood area measured. A distinct environmental gradient exists between the two sites with higher atmospheric CO2 concentrations in the proximity of a natural CO2 spring. Trees at the spring site have been growing for generations in elevated atmospheric CO2 concentrations. At both sites, maximum leaf conductance was related to predawn shoot water potential. The effects of water deficits on water relations and whole-plant transpiration during the summer drought were severe. Leaf conductance and water potential recovered after major rainfall in September to predrought values. Sap flow, leaf conductance and predawn water potential decreased in parallel with increases in hydraulic resistance, reaching a minimum in mid-summer. These relationships are in agreement with the hypothesis of the stomatal control of transpiration to prevent desiccation damage but also to avoid ‘runaway embolism’. Trees at the CO2 spring underwent less reduction in hydraulic resistance for a given value of predawn water potential. The decrease in leaf conductance caused by elevated CO2 was limited and tended to be less at high than at low atmospheric vapour pressure deficit. Mean (and diurnal) sap flux were consistently higher in the control site trees than in the CO2 spring trees. The degree of reduction in water use between the two sites varied among the summer periods. The control site trees had consistently higher sap flow at corresponding values of either sapwood cross-sectional area or foliage area. Larger trees displayed smaller differences than smaller trees, between the control and the CO2 spring trees. A strong association between foliage area and sapwood cross-sectional area was found in both the control and the CO2 spring trees, the latter supporting a smaller foliage area at the corresponding sapwood stem cross-sectional area. The specific leaf area (SLA) of the foliage was not influenced by site. The results are discussed in terms of the effects of elevated CO2 on plant water use at the organ and whole-tree scale.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Chiarucci, Alessandro</style></author><author><style face="normal" font="default" size="100%">Robinson, Brett H.</style></author><author><style face="normal" font="default" size="100%">Bonini, Ilaria</style></author><author><style face="normal" font="default" size="100%">Petit, Daniel</style></author><author><style face="normal" font="default" size="100%">Brooks, Robert R.</style></author><author><style face="normal" font="default" size="100%">Dominicis, Vincenzo</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Vegetation of tuscan ultramafic soils in relation to edaphic and physical factors</style></title><secondary-title><style face="normal" font="default" size="100%">Folia Geobotanica</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">canonical correspondence analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">serpentine</style></keyword><keyword><style  face="normal" font="default" size="100%">soil features</style></keyword><keyword><style  face="normal" font="default" size="100%">species diversity</style></keyword><keyword><style  face="normal" font="default" size="100%">vegetation ecology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1998///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/10.1007/BF02913340</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">113 - 131</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Vegetation and soil sampling were carried out in 80 plots located in five different ultramafic (serpentine) sites of Tuscany, central Italy. The physical and chemical features of each plot. were determined and the species composition and cover recorded. The exchangeable fraction of soil metals was analysed because it gives a measure of their concentrations available to plants. The plots were classified by cluster analysis and ANOVA was used to compare the environmental variables of the groups of plots. Canonical correspondence analysis was used to detect the principal factors for gradients of species composition within the plant communities. A higher content of exchangeable metals was found under the more evolved and structured plant communities, suggesting that serpentine vegetation of Tuscany is not strongly limited by soil metals, such as chromium, cobalt, nickel and magnesium, typically associated with ultramafic soils. The low nutrient content of the soils and drought stress mainly due to topographical features, appear to have a more significant role in determining the typical scattered vegetation of the Tuscan ultramafics.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tognetti, R</style></author><author><style face="normal" font="default" size="100%">Longobucco, A</style></author><author><style face="normal" font="default" size="100%">Raschi, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Vulnerability of xylem to embolism in relation to plant hydraulic resistance in Quercus pubescens and Quercus ilex co-occurring in a Mediterranean coppice stand in central Italy</style></title><secondary-title><style face="normal" font="default" size="100%">New Phytologist</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cavitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydraulic resistance</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex L.</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus pubescens Willd.</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword><keyword><style  face="normal" font="default" size="100%">xylem embolism</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">Cambridge University Press</style></publisher><volume><style face="normal" font="default" size="100%">139</style></volume><pages><style face="normal" font="default" size="100%">437-447</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The seasonal patterns of xylem embolism and xylem transport properties in Quercus pubescens Willd. and Quercus ilex L. trees growing in a natural mixed coppice stand in conditions of severe water stress were investigated. Xylem embolism was evaluated in both dehydrating branches and in apical twigs during a whole year. Measurements of xylem water potential were conducted from predawn to sunset on selected sunny days. On the same days, diurnal courses of leaf conductance were monitored. Measurements of half-hourly sap flow were made by the heat-pulse technique throughout the summer. At the onset of summer, a sharp decrease in water potential was observed in both species. Full recovery of water potentials was observed for both species after the first major rainfall event in September. Both experienced serious embolism throughout the year, ranging between minima of c. 60% (expressed as percentage loss of hydraulic conductivity) after the rains in autumn and after bud burst in spring, and maxima of c. 80% during summer and after freezing-thawing events during the winter season. A significant negative linear relationship was found between water potential and xylem embolism in branches dehydrating in air for Q. pubescens and Q. ilex. Q. pubescens had greater efficiency in hydraulic transport (higher specific conductivity and leaf specific conductivity) by the xylem than Q. ilex. In June, leaf conductance was high early in the morning and decreased gradually during the day. Midday depression of leaf conductance, as a result of high evaporative demand combined with water deficit, was observed in both species. In August, leaf conductance of both species was greatly reduced, as water potential dropped to extremely low values, and the stomata were almost completely closed during the afternoon. No hysteresis resulting from plant capacitance was observed in the relationship between shoot water potential and sap flow. Q. pubescens exhibited very high values of whole-tree hydraulic resistance between July and September, whereas Q. ilex generally showed lower values. The effect of soil moisture depletion on the relationship between sap flow and shoot water potential appears as a lowering of water potential at zero flow. A significant decrease of whole-tree hydraulic resistance in both species was observed with the onset of the autumn, preceding the partial recovery of twig hydraulic conductivity. The results demonstrate that both Q. pubescens and Q. ilex, although highly tolerant of severe water stress and tissue dehydration, operate at the limits of safety which are surpassed under severe droughts, and prolonged climatic stress might predispose these Quercus species to decline.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Figueroa, M. E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Chlorophyll fluorescence, stress and survival in populations of Mediterranean grassland species</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Vegetation Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Fv/Fm</style></keyword><keyword><style  face="normal" font="default" size="100%">mortality</style></keyword><keyword><style  face="normal" font="default" size="100%">Photo-inhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosystem II</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1997///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://onlinelibrary.wiley.com/doi/10.2307/3237033/full</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">8</style></volume><pages><style face="normal" font="default" size="100%">881 - 888</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Photosynthetic stress in response to a natural episode of frost and seasonal drought was assessed in a ‘dehesa’ grassland of SW Spain with a portable fluorimeter. Chlorophyll fluorescence characteristics of dark-adapted leaves of 11 abundant species of Mediterranean grassland were measured over the course of a growing season from November 1992 to July 1993. Concomitant changes in population size were estimated from censuses of permanent quadrats. There was a general decline in the photochemical efficiency (F v /Fm ) during the growing season and this was particularly evident late in the growing season (spring and early summer) when ambient temperatures were increasing rapidly and rainfall was low; it coincided with the period of most intense mortality for most species. A frost in early March (– 5 °C), when photosynthetically active radiation was relatively high, resulted in a small decrease in F v /Fm that was consistent across many species. The mechanisms of protection in species of Mediterranean grassland appear to be sufficiently effective to avoid damage to PSII for most of the year. For most species there was little evidence of photosystem II damage, as initial fluorescence (F 0 ) usually did not increase. Many of the effects observed were due to a reduction in Fm and thus were consistent with non-photochemical quenching. This could be adaptive in protecting PSII from damage in species that show little evidence of stress. The sharp increase in stress toward the end of the life cycle coincided with the fall in net population size.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Figueroa, M E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Chlorophyll fluorescence, stress and survival in populations of Mediterranean grassland species</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Vegetation Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Fv/Fm</style></keyword><keyword><style  face="normal" font="default" size="100%">mortality</style></keyword><keyword><style  face="normal" font="default" size="100%">Photo-inhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">photochemical efficiency</style></keyword><keyword><style  face="normal" font="default" size="100%">Photosystem II</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><volume><style face="normal" font="default" size="100%">8</style></volume><pages><style face="normal" font="default" size="100%">881-888</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Photosynthetic stress in response to a natural episode of frost and seasonal drought was assessed in a ‘dehesa’ grassland of SW Spain with a portable fluorimeter. Chlorophyll fluorescence characteristics of dark-adapted leaves of 11 abundant species of Mediterranean grassland were measured over the course of a growing season from November 1992 to July 1993. Concomitant changes in population size were estimated from censuses of permanent quadrats. There was a general decline in the photochemical efficiency (F v /Fm ) during the growing season and this was particularly evident late in the growing season (spring and early summer) when ambient temperatures were increasing rapidly and rainfall was low; it coincided with the period of most intense mortality for most species. A frost in early March (– 5 °C), when photosynthetically active radiation was relatively high, resulted in a small decrease in F v /Fm that was consistent across many species. The mechanisms of protection in species of Mediterranean grassland appear to be sufficiently effective to avoid damage to PSII for most of the year. For most species there was little evidence of photosystem II damage, as initial fluorescence (F 0 ) usually did not increase. Many of the effects observed were due to a reduction in Fm and thus were consistent with non-photochemical quenching. This could be adaptive in protecting PSII from damage in species that show little evidence of stress. The sharp increase in stress toward the end of the life cycle coincided with the fall in net population size.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Radoglou, K</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Environmental control of CO2 assimilation rates and stomatal conductance in five oak species growing under field conditions in Greece</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">assimilation rate</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus sp</style></keyword><keyword><style  face="normal" font="default" size="100%">Seasonality</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">269-278</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The present study compared CO2 assimilation rate and stomatal conductance of five oak species from the beginning of May through November 1993 under similar natural conditions. Gas exchange, leaf characteristics and water status were measured on 30-year-old Quercus ilex, Q macrolepis, Q pedunculiflora, Q pubescens and Q trojana growing in experimental plots in northern Greece. The seasonal pattern of assimilation rates was similar for all study species but differences occurred between the species. After initial leaf expansion, all species rapidly developed high photosynthetic rates. In addition, assimilation rates were high in all species in May and November after rain events. No significant differences in stomatal conductance were observed among species during the growing season. The relationships between assimilation rate and stomatal conductance displayed variation in the slopes among species and months.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Roupsard, O</style></author><author><style face="normal" font="default" size="100%">Gross, P</style></author><author><style face="normal" font="default" size="100%">Dreyer, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Limitation of photosynthetic activity by CO2 availability in the chloroplasts of oak leaves from different species and during drought</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">chloroplasts</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 diffusion</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">oaks</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">243-254</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">It has recently been suggested that the low photosynthesis rates in tree species as compared to highly productive crops is at least partly due to resistances opposing the CO 2 fluxes in the mesophyll of tree leaves. To validate this assertion, values of CO2 mole fractions in the chloroplasts of leaves from Quercus petraea, Q robur, Q ilex and Populus sp were estimated on the basis of the analysis of the partitioning of light driven electron flow between fractions used for the carboxylation or the oxygenation of RuBP by Rubisco. The procedure used included: i) a measure of total light driven electron flows derived from the chlorophyll a fluorescence ratio ΔF/Fm', which is proportional to the photochemical efficiency of PS II, multiplied by incident irradiance and a calibration coefficient; ii) an estimation of the electron flux devoted to carboxylation obtained from net CO2 assimilation and respiration rate measurement, and using the known electron requirements (four electrons for CO2 or O2 fixation); iii) the derivation of the CO2 mole fraction in the chloroplasts from the specificity factor of Rubisco, and the ratio of carboxylation/oxygenation of RuBP. Results showed that in the absence of drought stress, the mole fraction of CO2 in the chloroplasts (35-45% of the atmospheric one) was much lower than the calculated substomatal one (60-70% of the atmospheric) in all species. Moreover, lowest values were recorded in the species with lowest assimilation rates, suggesting that the differences in the net CO 2 assimilation rate between species are linked to the CO2 availability in the chloroplasts. Finally, the CO2 availability decreased with increasing drought in the soil, stressing the importance of reduced influx of CO2 as an important factor for drought-induced declines of photosynthesis. These results are discussed with respect to the occurrence of significant resistances in the leaf mesophyll, in addition to the stomatal resistances.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Roupsard, O.</style></author><author><style face="normal" font="default" size="100%">Gross, P.</style></author><author><style face="normal" font="default" size="100%">Dreyer, E.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Limitation of photosynthetic activity by CO2 availability in the chloroplasts of oak leaves from different species and during drought</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">chlorophyll fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">chloroplasts</style></keyword><keyword><style  face="normal" font="default" size="100%">CO2 diffusion</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">mesophyll conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">oaks</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1996///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1051/forest:19960207</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">243 - 254</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">It has recently been suggested that the low photosynthesis rates in tree species as compared to highly productive crops is at least partly due to resistances opposing the CO 2 fluxes in the mesophyll of tree leaves. To validate this assertion, values of CO2 mole fractions in the chloroplasts of leaves from Quercus petraea, Q robur, Q ilex and Populus sp were estimated on the basis of the analysis of the partitioning of light driven electron flow between fractions used for the carboxylation or the oxygenation of RuBP by Rubisco. The procedure used included: i) a measure of total light driven electron flows derived from the chlorophyll a fluorescence ratio ΔF/Fm', which is proportional to the photochemical efficiency of PS II, multiplied by incident irradiance and a calibration coefficient; ii) an estimation of the electron flux devoted to carboxylation obtained from net CO2 assimilation and respiration rate measurement, and using the known electron requirements (four electrons for CO2 or O2 fixation); iii) the derivation of the CO2 mole fraction in the chloroplasts from the specificity factor of Rubisco, and the ratio of carboxylation/oxygenation of RuBP. Results showed that in the absence of drought stress, the mole fraction of CO2 in the chloroplasts (35-45% of the atmospheric one) was much lower than the calculated substomatal one (60-70% of the atmospheric) in all species. Moreover, lowest values were recorded in the species with lowest assimilation rates, suggesting that the differences in the net CO 2 assimilation rate between species are linked to the CO2 availability in the chloroplasts. Finally, the CO2 availability decreased with increasing drought in the soil, stressing the importance of reduced influx of CO2 as an important factor for drought-induced declines of photosynthesis. These results are discussed with respect to the occurrence of significant resistances in the leaf mesophyll, in addition to the stomatal resistances.</style></abstract><issue><style face="normal" font="default" size="100%">2-3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brasier, C M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Phytophthora cinnamomi and oak decline in southern Europe. Environmental constraints including climate change</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">climate change</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Oak decline</style></keyword><keyword><style  face="normal" font="default" size="100%">phytophthora cinnamomi</style></keyword><keyword><style  face="normal" font="default" size="100%">root pathogen</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">347-358</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">One of the most destructive of all tree root pathogens, the oomycete fungus Phytophthora cinnamomi, is associated with mortality and decline of Quercus suber and Q ilex in the Mediterranean region. The symptoms and distribution of this decline are described. P cinnamomi is a primary pathogen on a very wide range of trees and woody ornamentals worldwide, but is probably a native of the Papua New Guinea region. It is soil borne and requires warm, wet soils to infect roots. Since 1900 it has caused major epidemics on native chestnuts in the United States and Europe, and now threatens the stability of entire forest and heath communities ecosystems in some parts of Australia. Together with drought, it may be a major predisposing factor in the Iberian oak decline. Its possible role in this decline including its interaction with drought is discussed, and a generalised working hypothesis of decline is presented. The potential influence of climate warming on the activity of P cinnamomi is also considered. A model based on the CLIMEX program suggests that warming would significantly enhance the activity of the pathogen at its existing disease locations (such as the western Mediterranean and coastal northwest Europe), but that it would not greatly extend its activity into areas with cold winters such as central and eastern Europe</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Tognetti, R</style></author><author><style face="normal" font="default" size="100%">Giovannelli, A</style></author><author><style face="normal" font="default" size="100%">Longobucco, A</style></author><author><style face="normal" font="default" size="100%">Miglietta, F</style></author><author><style face="normal" font="default" size="100%">Raschi, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Water relations of oak species growing in the natural CO2 spring of Rapolano (central Italy)</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Elevated CO2</style></keyword><keyword><style  face="normal" font="default" size="100%">embolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus pubescens</style></keyword><keyword><style  face="normal" font="default" size="100%">sap flow</style></keyword><keyword><style  face="normal" font="default" size="100%">water relations</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><volume><style face="normal" font="default" size="100%">53</style></volume><pages><style face="normal" font="default" size="100%">475-485</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effect of elevated atmospheric carbon dioxide on water relations was examined on downy oak (Quercus pubescens) and holm oak (Q ilex) trees. The study was conducted on trees growing in a naturally enriched CO2 spring. Sap velocity and sap flow were measured by the heat pulse technique. On the same trees, daily courses of xylem water potential, leaf conductance and transpiration were monitored. Plant water relations were evaluated by pressure-volume analysis method on shoots; on the same branches, relative conductivity of xylem was measured. Both species exhibited increased osmotic potential and decreased symplasmic fraction of water in trees adapted to increased CO2. Downy oak showed lower stomatal conductance under elevated CO2, but holm oak did not. Both species displayed higher sap flow in control trees. In both species, increased carbon dioxide did not influence xylem embolism formation.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brasier, C. M.</style></author><author><style face="normal" font="default" size="100%">ROBREDO, F.</style></author><author><style face="normal" font="default" size="100%">FERRAZ, J. F. P.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evidence for Phytophthora cinnamomi involvement in Iberian oak decline</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Pathology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Oak decline</style></keyword><keyword><style  face="normal" font="default" size="100%">phytophthora cinnamomi</style></keyword><keyword><style  face="normal" font="default" size="100%">site factors (PG)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1993///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://dx.doi.org/10.1111/j.1365-3059.1993.tb01482.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">140 - 145</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rapid and sometimes extensive mortality and decline of oak, principally Quercus suber and Q. ilex, has occurred in parts of southern Spain and Portugal in recent decades. We report here isolation of the aggressive root pathogen Phytophthora cinnamomi from roots of diseased oaks or from soil at eleven out of thirteen decline foci examined. It is proposed that the introduction and spread of P. cinnamomi may be a major factor in the Iberian oak decline, interacting with drought and other site factors, and leading to stress-related attacks by insects and other fungi. By analogy, it may also be involved in the similar oak declines occurring elsewhere on the Mediterranean.</style></abstract><issue><style face="normal" font="default" size="100%">1</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;publisher: Blackwell Publishing Ltd</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Brasier, C M</style></author><author><style face="normal" font="default" size="100%">ROBREDO, F</style></author><author><style face="normal" font="default" size="100%">FERRAZ, J F P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Evidence for Phytophthora cinnamomi involvement in Iberian oak decline</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Pathology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">Oak decline</style></keyword><keyword><style  face="normal" font="default" size="100%">phytophthora cinnamomi</style></keyword><keyword><style  face="normal" font="default" size="100%">site factors (PG)</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Publishing Ltd</style></publisher><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">140-145</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Rapid and sometimes extensive mortality and decline of oak, principally Quercus suber and Q. ilex, has occurred in parts of southern Spain and Portugal in recent decades. We report here isolation of the aggressive root pathogen Phytophthora cinnamomi from roots of diseased oaks or from soil at eleven out of thirteen decline foci examined. It is proposed that the introduction and spread of P. cinnamomi may be a major factor in the Iberian oak decline, interacting with drought and other site factors, and leading to stress-related attacks by insects and other fungi. By analogy, it may also be involved in the similar oak declines occurring elsewhere on the Mediterranean.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Epron, D</style></author><author><style face="normal" font="default" size="100%">Dreyer, E</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stomatal and non stomatal limitation of photosynthesis by leaf water deficits in three oak species: a comparison of gas exchange and chlorophyll a fluorescence data</style></title><secondary-title><style face="normal" font="default" size="100%">Ann. For. Sci.</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Chlorophyll a fluorescence</style></keyword><keyword><style  face="normal" font="default" size="100%">Drought</style></keyword><keyword><style  face="normal" font="default" size="100%">oak</style></keyword><keyword><style  face="normal" font="default" size="100%">photoinhibition</style></keyword><keyword><style  face="normal" font="default" size="100%">photosynthesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Stomatal conductance</style></keyword><keyword><style  face="normal" font="default" size="100%">water stress</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1990</style></year></dates><volume><style face="normal" font="default" size="100%">47</style></volume><pages><style face="normal" font="default" size="100%">435-450</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Net CO2 assimilation (A), stomatal conductance for CO2 (g), intercellular mole fraction of CO2 (Ci), kinetics of chlorophyll a fluorescence, and their half decay time (t1/2), their ratio of fluorescence decrease (Rfd), and their adaptive index (Ap) have been monitored on potted trees from 3 oak species (Quercus petraea, Q pubescens and Q ilex) grown in a climate chamber and submitted to drought. Use of A vs Ci representations for photosynthesis data revealed an apparent impairment of mesophyll photosynthesis, together with reduced CO2 supply to mesophyll due to stomatal closure. But in all species chlorophyll a fluorescence kinetics displayed very similar shapes, constant t1/2 and stable Rfd and Ap values until predawn leaf water potential dropped below -4.0 MPa. These observations led to the conclusion that photochemical energy conversion and photosynthetic carbon reduction cycle could be very resistant to leaf water deficits, and that observed decreases in mesophyll photosynthesis had to be attributed to a possible artefact in Ci calculation. On the other hand, the susceptibility of leaves to photoinhibition increased as a consequence of water shortage, especially in Q petraea and Q pubescens. Differences in drought adaptation between the studied species could probably be related to susceptibility to photoinhibition rather than to a direct sensitivity of photosynthesis to leaf water deficits, at least in the range of stress intensities of ecophysiological significance.</style></abstract></record></records></xml>