<?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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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%">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, 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%">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>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><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%">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%">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%">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%">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%">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%">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%">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%">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><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></records></xml>