<?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%">Uribe, C</style></author><author><style face="normal" font="default" size="100%">Inclán, R</style></author><author><style face="normal" font="default" size="100%">Sanchez, D M</style></author><author><style face="normal" font="default" size="100%">Clavero, M A</style></author><author><style face="normal" font="default" size="100%">Fernandez, A M</style></author><author><style face="normal" font="default" size="100%">Morante, R</style></author><author><style face="normal" font="default" size="100%">Cardena, A</style></author><author><style face="normal" font="default" size="100%">Blanco, A</style></author><author><style face="normal" font="default" size="100%">Van Miegroet, H</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of wildfires on soil respiration in three typical Mediterranean forest ecosystems in Madrid, Spain</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%">Pinus sylvestris</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus pyrenaica</style></keyword><keyword><style  face="normal" font="default" size="100%">soil parameters</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">wildfires</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">369</style></volume><pages><style face="normal" font="default" size="100%">403-420</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mediterranean forests are vulnerable to numerous threats including wildfires due to a combination of climatic factors and increased urbanization. In addition, increased temperatures and summer drought lead to increased risk of forest fires as a result of climate change. This may have important consequences for C dynamics and balance in these ecosystems. Soil respiration was measured over 2 successive years in Holm oak (Quercus ilex subsp. ballota; Qi); Pyrenean Oak (Quercus pyrenaica Willd; Qp); and Scots pine (Pinus sylvestris L.; Ps) forest stands located in the area surrounding Madrid (Spain), to assess the long term effects of wildfires on C efflux from the soil, soil properties, and the role of soil temperature and soil moisture in the variation of soil respiration. Soil respiration, soil temperature, soil moisture, fine root mass, microbial biomass, biological and chemical soil parameters were compared between non burned (NB) and burned sites (B). The annual C losses through soil respiration from NB sites in Qi, Qp and Ps were 790, 1010, 1380 gCm(-2) yr(-1), respectively, with the B sites emitting 43 %, 22 % and 11 % less in Qi, Qp and Ps respectively. Soil microclimate changed with higher soil temperature and lower soil moisture in B sites after fire. Exchangeable cations and the pH also decreased. The total SOC stocks were not significantly altered, but 6-8 years after wildfires, there was still measurably lower fine root and microbial biomass, while SOC quality changed, indicated by lower the C/N ratio and the labile carbon and a relative increase in refractory SOC forms, which resulted in lower Q(10) values. We found long term effects of wildfires on the physical, chemical and biological soil characteristics, which in turn affected soil respiration. The response of soil respiration to temperature was controlled by moisture and changed with ecosystem type, season, and between B and NB sites. Lower post-burn Q(10) integrated the loss of roots and microbial biomass, change in SOC quality and a decrease in soil moisture.</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%">Gómez-Rey, Maria Xesús</style></author><author><style face="normal" font="default" size="100%">Madeira, Manuel</style></author><author><style face="normal" font="default" size="100%">Gonzalez-Prieto, Serafin Jesús</style></author><author><style face="normal" font="default" size="100%">Coutinho, João</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil C and N dynamics in a Mediterranean oak woodland with shrub encroachment</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%">15 N isotope dilution technique</style></keyword><keyword><style  face="normal" font="default" size="100%">gross N mineralization</style></keyword><keyword><style  face="normal" font="default" size="100%">hot water-soluble C</style></keyword><keyword><style  face="normal" font="default" size="100%">particulate organic matter</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><volume><style face="normal" font="default" size="100%">371</style></volume><pages><style face="normal" font="default" size="100%">339-354</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Background and aims Intensive land use has led to degradation and abandonment of Portuguese oak woodlands, and subsequent shrub encroachment may have altered the spatial heterogeneity of soil C and N pools. The aim of this study was to evaluate the effects of shrub invasion on soil C and N dynamics in an oak woodland in Southern Portugal. Methods Soil was sampled beneath and outside scat- tered Quercus suber L. canopies, considering non- encroached areas and areas encroached by shrubs (Cistus ladanifer L. or Cistus salviifolius L.). Results The spatial heterogeneity of soil C and N contents was mainly associated with tree presence. Outside tree canopies, the labile C pools were larger (mainly beneath C. ladanifer) and C cycling was faster in encroached areas than in non-encroached areas. Net and gross N mineralization and urease and protease activities were also higher in encroached than in non- encroached areas; however, the metabolic quotient and the Cmicrobial/Corganic ratio were not significantly affected. Beneath the tree canopy, significant effects of encroachment included a small increase in soil labile C and the enzymatic activity beneath C. ladanifer. Conclusions The results indicate the potential capaci- ty of shrub encroachment to accumulate soil organic C in the long term. The rate of soil C and N turnover promoted by shrub encroachment may depend on the Cistus species present.</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%">Correia, a C. C.</style></author><author><style face="normal" font="default" size="100%">Minunno, F.</style></author><author><style face="normal" font="default" size="100%">Caldeira, M. C. C.</style></author><author><style face="normal" font="default" size="100%">Banza, J.</style></author><author><style face="normal" font="default" size="100%">Mateus, J.</style></author><author><style face="normal" font="default" size="100%">Carneiro, M.</style></author><author><style face="normal" font="default" size="100%">Wingate, L.</style></author><author><style face="normal" font="default" size="100%">Shvaleva, a</style></author><author><style face="normal" font="default" size="100%">Ramos, a</style></author><author><style face="normal" font="default" size="100%">Jongen, M.</style></author><author><style face="normal" font="default" size="100%">Bugalho, M. N. N.</style></author><author><style face="normal" font="default" size="100%">Nogueira, C.</style></author><author><style face="normal" font="default" size="100%">Lecomte, X.</style></author><author><style face="normal" font="default" size="100%">Pereira, J. S. S.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil water availability strongly modulates soil CO2 efflux in different Mediterranean ecosystems: Model calibration using the Bayesian approach</style></title><secondary-title><style face="normal" font="default" size="100%">Agriculture, Ecosystems &amp; Environment</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bayesian calibration</style></keyword><keyword><style  face="normal" font="default" size="100%">Empirical model</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil CO2 efﬂux</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil moisture</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil temperature</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/S016788091200285X</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">161</style></volume><pages><style face="normal" font="default" size="100%">88 - 100</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil respiration in drought prone regions is highly dependent on the precipitation regime and soil moisture conditions, which are expected to change in a global warming context. In the present study we used an extensive collection of ﬁeld chamber measurements of soil respiration (Rs ) from forest and grassland sites of centre and south of Portugal distributed over a 10 year period. This data were summarized and analysed with the objective to describe seasonal variability of Rs as affected by soil moisture (Hs ) and soil temperature (Ts ). A Bayesian framework was used to test the effectiveness of soil bioclimatic models in estimating Rs on a daily and monthly time step. Rs seasonality was similar between sites, reaching a maximum in spring and autumn and a minimum in the dry season (July–September). No differences were observed for Rs between sites with different standing biomass or soil carbon stocks either on an annual or seasonal timescale. Hs , and not Ts , was the driving factor of Rs during most of the year. Ts drove Rs response only above certain Hs limits: 10% for forest sites and 15% for grassland sites leading to a Q10 of 2.01, 1.61 and 1.31 for closed forests, open forests and grasslands, respectively. The Bayesian analysis showed that models using Hs as an independent variable performed better than models driven by Ts alone. Monthly estimates of Rs in grasslands can be predicted by simple climatic models based on Hs but none of them was suitable for forest ecosystems, stressing the need for a process-based approach. This study adds to the evidence that Hs controls Rs ﬂuxes for Mediterranean ecosystems and should always be taken into account for extrapolation purposes.</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%">Unger, Stephan</style></author><author><style face="normal" font="default" size="100%">Máguas, Cristina</style></author><author><style face="normal" font="default" size="100%">Pereira, João S.</style></author><author><style face="normal" font="default" size="100%">David, Teresa S.</style></author><author><style face="normal" font="default" size="100%">Werner, Christiane</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The influence of precipitation pulses on soil respiration – Assessing the “Birch effect” by stable carbon isotopes</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Birch effect</style></keyword><keyword><style  face="normal" font="default" size="100%">d13C</style></keyword><keyword><style  face="normal" font="default" size="100%">Irrigation experiment</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean woodland</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Stable isotopes</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://linkinghub.elsevier.com/retrieve/pii/S0038071710002282</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><pages><style face="normal" font="default" size="100%">1800 - 1810</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Sudden pulse-like events of rapidly increasing CO2-efﬂux occur in soils under seasonally dry climates in response to rewetting after drought. These occurrences, termed “Birch effect”, can have a marked inﬂuence on the ecosystem carbon balance. Current hypotheses indicate that the “Birch” pulse is caused by rapidly increased respiration and mineralization rates in response to changing moisture conditions but the underlying mechanisms are still unclear. Here, we present data from an experimental ﬁeld study using straight-forward stable isotope methodology to gather new insights into the processes induced by rewetting of dried soils and evaluate current hypotheses for the “Birch“-CO2-pulse. Two irrigation experiments were conducted on bare soil, root-free soil and intact vegetation during May and August 2005 in a semi-arid Mediterranean holm oak forest in southern Portugal. We continuously monitored CO2-ﬂuxes along with their isotopic compositions before, during and after the irrigation. d 13 C signatures of the ﬁrst CO2-efﬂux burst, occurring immediately after rewetting, ﬁt the hypothesis that the “Birch” pulse is caused by the rapid mineralization of either dead microbial biomass or osmoregulatory substances released by soil microorganisms in response to hypo-osmotic stress in order to avoid cell lyses. The response of soil CO2-efﬂux to rewetting was smaller under mild (May) than under severe drought (August) and isotopic compositions indicated a larger contribution of anaplerotic carbon uptake with increasing soil desiccation. Both length and severity of drought periods probably play a key role for the microbial response to the rewetting of soils and thus for ecosystem carbon sequestration.</style></abstract><issue><style face="normal" font="default" size="100%">10</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%">Llorente, Mireia</style></author><author><style face="normal" font="default" size="100%">Turrión, M Belén</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Microbiological parameters as indicators of soil organic carbon dynamics in relation to different land use management</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Calcareous soil</style></keyword><keyword><style  face="normal" font="default" size="100%">Metabolic quotient</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">129</style></volume><pages><style face="normal" font="default" size="100%">73-81</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Labile C fractions: microbial biomass C (MBC), K2SO4 extractable C (CK2SO4 ) and the cumulated mineralized C in 21 days incubation at 28C (C–CO2(21d) ), were compared as land use indicators in a calcareous soil under three different management systems: native Querqus ilex forest (under and outside tree cover), a Pinus halepensis plantation, and cropped land (with cereals). Microbial biomass and activity were found to be low and coincided with high carbonate contents. As indicators of land use, CK2SO4 and C–CO2(21d) showed the same sensitivity as MBC. C–CO2 emissions were measured in an incubation experiment in order to study C mineralization kinetics. The data for cumulative amounts of C–CO2 released showed a good ﬁt (R 2 [0.94) to the ﬁrst-order kinetic model Cm = Co(1 - e -kt ). The kinetic parameters Co and Cok were affected by land use and especially by tree cover. Principal components analysis was applied to the data and the relationship among microbial metabolic quotient (qCO2), labile C pools, and MBC revealed a decrease in efﬁciency of organic substrate utilization with an increase in availability and lability of the organic matter.</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%">Llorente, Mireia</style></author><author><style face="normal" font="default" size="100%">Turrión, M. Belén</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Microbiological parameters as indicators of soil organic carbon dynamics in relation to different land use management</style></title><secondary-title><style face="normal" font="default" size="100%">European Journal of Forest Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Calcareous soil</style></keyword><keyword><style  face="normal" font="default" size="100%">Metabolic quotient</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</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.springerlink.com/index/10.1007/s10342-008-0249-z</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">129</style></volume><pages><style face="normal" font="default" size="100%">73 - 81</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Labile C fractions: microbial biomass C (MBC), K2SO4 extractable C (CK2SO4 ) and the cumulated mineralized C in 21 days incubation at 28C (C–CO2(21d) ), were compared as land use indicators in a calcareous soil under three different management systems: native Querqus ilex forest (under and outside tree cover), a Pinus halepensis plantation, and cropped land (with cereals). Microbial biomass and activity were found to be low and coincided with high carbonate contents. As indicators of land use, CK2SO4 and C–CO2(21d) showed the same sensitivity as MBC. C–CO2 emissions were measured in an incubation experiment in order to study C mineralization kinetics. The data for cumulative amounts of C–CO2 released showed a good ﬁt (R 2 [0.94) to the ﬁrst-order kinetic model Cm = Co(1 - e -kt ). The kinetic parameters Co and Cok were affected by land use and especially by tree cover. Principal components analysis was applied to the data and the relationship among microbial metabolic quotient (qCO2), labile C pools, and MBC revealed a decrease in efﬁciency of organic substrate utilization with an increase in availability and lability of the organic matter.</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%">Casals, Pere</style></author><author><style face="normal" font="default" size="100%">Gimeno, Cristina</style></author><author><style face="normal" font="default" size="100%">Carrara, Arnaud</style></author><author><style face="normal" font="default" size="100%">Lopez-Sangil, Luis</style></author><author><style face="normal" font="default" size="100%">Sanz, MJosé</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil CO2 efflux and extractable organic carbon fractions under simulated precipitation events in a Mediterranean Dehesa</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Chloroform-fumigation K2SO4-extraction</style></keyword><keyword><style  face="normal" font="default" size="100%">drying-rewetting cycles</style></keyword><keyword><style  face="normal" font="default" size="100%">holm oak savanna woodland</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil C fractions</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</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/S0038071709002260</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">1915 - 1922</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The magnitude of CO2 efﬂux pulses after rewetting a dry soil is highly variable and the factors regulating these pulses are poorly understood. In this ﬁeld experiment, we aimed to study the C dynamics after simulated summer rainstorms in a Mediterranean open holm oak woodland (dehesa). We hypothesized that because the herbaceous cover is mostly dead during the summer in this ecosystem, the short-term CO2 efﬂux (SR) after rewetting could mainly be explained by different measurable soil C fractions: i) K2SO4-extracted soil C (EOC); ii) microbial biomass C (MBC); or iii) chloroform-fumigated extracted C (CFE). On both grazed and abandoned dehesa sites, we simulated three summer rain events at two-week intervals and we measured SR discontinuously in three plots under tree canopy and in another three plots in open grassland. In each plot, C fractions and water content were estimated before (2 h) and after (36 h) each irrigation event. Following rewettings, SR increased up to ten times compared with nonirrigated plots. The CFE actually increased after rewetting in the ﬁrst two irrigations but not in the third event, suggesting that the capacity of the soil to release labile organic C from soil aggregates or litter was reduced after each irrigation event. Overall, the C released as CO2 in the ﬁrst 24 h was related to the CFE existing before rewetting, which may help to explain the spatial variability in SR. However, the explained variability decreased after each irrigation, suggesting a change to a less labile composition of the CFE fraction as a consequence of multiple drying-rewetting cycles</style></abstract><issue><style face="normal" font="default" size="100%">9</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%">Casals, Pere</style></author><author><style face="normal" font="default" size="100%">Gimeno, Cristina</style></author><author><style face="normal" font="default" size="100%">Carrara, Arnaud</style></author><author><style face="normal" font="default" size="100%">Lopez-Sangil, Luis</style></author><author><style face="normal" font="default" size="100%">Sanz, MJosé</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil CO2 efflux and extractable organic carbon fractions under simulated precipitation events in a Mediterranean Dehesa</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Chloroform-fumigation K2SO4-extraction</style></keyword><keyword><style  face="normal" font="default" size="100%">drying-rewetting cycles</style></keyword><keyword><style  face="normal" font="default" size="100%">holm oak savanna woodland</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil C fractions</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><volume><style face="normal" font="default" size="100%">41</style></volume><pages><style face="normal" font="default" size="100%">1915-1922</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The magnitude of CO2 efﬂux pulses after rewetting a dry soil is highly variable and the factors regulating these pulses are poorly understood. In this ﬁeld experiment, we aimed to study the C dynamics after simulated summer rainstorms in a Mediterranean open holm oak woodland (dehesa). We hypothesized that because the herbaceous cover is mostly dead during the summer in this ecosystem, the short-term CO2 efﬂux (SR) after rewetting could mainly be explained by different measurable soil C fractions: i) K2SO4-extracted soil C (EOC); ii) microbial biomass C (MBC); or iii) chloroform-fumigated extracted C (CFE). On both grazed and abandoned dehesa sites, we simulated three summer rain events at two-week intervals and we measured SR discontinuously in three plots under tree canopy and in another three plots in open grassland. In each plot, C fractions and water content were estimated before (2 h) and after (36 h) each irrigation event. Following rewettings, SR increased up to ten times compared with nonirrigated plots. The CFE actually increased after rewetting in the ﬁrst two irrigations but not in the third event, suggesting that the capacity of the soil to release labile organic C from soil aggregates or litter was reduced after each irrigation event. Overall, the C released as CO2 in the ﬁrst 24 h was related to the CFE existing before rewetting, which may help to explain the spatial variability in SR. However, the explained variability decreased after each irrigation, suggesting a change to a less labile composition of the CFE fraction as a consequence of multiple drying-rewetting cycles</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%">Piñol, J.</style></author><author><style face="normal" font="default" size="100%">Alcañiz, J. M.</style></author><author><style face="normal" font="default" size="100%">Roda, F.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Carbon dioxide efflux and pCO 2 in soils of threeQuercus ilex montane forests</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">soil atmosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1995///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.springerlink.com/index/P8U8167914T25968.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">191 - 215</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil CO2 efflux and pCO2 in the soil atmosphere were measured during one year at three montane sites of Mediterranean sclerophyllous forests in NE Spain. Two sites were located in the upper and lower slopes of a small catchment in the Prades mountains (mean precipitation 550 mm year-'), and a third site was located on a lower slope in the Montseny mountains (mean precipitation 900 mm year-'). The three sites were similar in bedrock and vegetation, but differed in soil characteristics and water availability. Seasonal variation of CO2 efflux and soil pCO2 were affected by soil temperature and, to a lesser extent, by soil moisture. Annual mean soil CO2 efflux (considered as soil respiration) was similar at Montseny and at the comparably located site at Prades (83 ± 18 S.E. vs. 75 4 9 mg CO2 m - 2 hour- , respectively), and was highest at the Prades upper slope site (122 ± 22 mg CO2 m -2 hour-l). Despite those relatively similar CO 2 effluxes, mean soil pCO2 was much higher at both Prades sites than at Montseny. Soil pCO2 always increased with depth at Prades while maxima pCO2 at Montseny were often at 20-30 cm depth. A model based on gas diffusion theory was able to explain why soil pCO2 was much higher at Prades than at Montseny, and to reproduce the shape of the vertical profile of pCO2 at the Prades soils. Nevertheless, the model failed to simulate the soil pCO2 maximum found at 20-30 cm depth at the Montseny site. Model simulations using a time-variable CO2 production rate suggested that pCO2 maxima at intermediate depth could be the result of a transient situation instead of an equilibrium one.</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%">Piñol, J</style></author><author><style face="normal" font="default" size="100%">Alcañiz, J M</style></author><author><style face="normal" font="default" size="100%">Rodà, F</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Carbon dioxide efflux and pCO 2 in soils of threeQuercus ilex montane forests</style></title><secondary-title><style face="normal" font="default" size="100%">Biogeochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">carbon cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystems</style></keyword><keyword><style  face="normal" font="default" size="100%">soil atmosphere</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year></dates><volume><style face="normal" font="default" size="100%">30</style></volume><pages><style face="normal" font="default" size="100%">191-215</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Soil CO2 efflux and pCO2 in the soil atmosphere were measured during one year at three montane sites of Mediterranean sclerophyllous forests in NE Spain. Two sites were located in the upper and lower slopes of a small catchment in the Prades mountains (mean precipitation 550 mm year-'), and a third site was located on a lower slope in the Montseny mountains (mean precipitation 900 mm year-'). The three sites were similar in bedrock and vegetation, but differed in soil characteristics and water availability. Seasonal variation of CO2 efflux and soil pCO2 were affected by soil temperature and, to a lesser extent, by soil moisture. Annual mean soil CO2 efflux (considered as soil respiration) was similar at Montseny and at the comparably located site at Prades (83 ± 18 S.E. vs. 75 4 9 mg CO2 m - 2 hour- , respectively), and was highest at the Prades upper slope site (122 ± 22 mg CO2 m -2 hour-l). Despite those relatively similar CO 2 effluxes, mean soil pCO2 was much higher at both Prades sites than at Montseny. Soil pCO2 always increased with depth at Prades while maxima pCO2 at Montseny were often at 20-30 cm depth. A model based on gas diffusion theory was able to explain why soil pCO2 was much higher at Prades than at Montseny, and to reproduce the shape of the vertical profile of pCO2 at the Prades soils. Nevertheless, the model failed to simulate the soil pCO2 maximum found at 20-30 cm depth at the Montseny site. Model simulations using a time-variable CO2 production rate suggested that pCO2 maxima at intermediate depth could be the result of a transient situation instead of an equilibrium one.</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%">Cotrufo, M. F.</style></author><author><style face="normal" font="default" size="100%">Santo, A. V. De</style></author><author><style face="normal" font="default" size="100%">Alfani, Anna</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effects of urban heavy metal pollution on organic matter decomposition in Quercus ilex L. Woods</style></title><secondary-title><style face="normal" font="default" size="100%">Environmental Pollution</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Fungal biomass (voyant9</style></keyword><keyword><style  face="normal" font="default" size="100%">Heavy metals</style></keyword><keyword><style  face="normal" font="default" size="100%">litter decomposition</style></keyword><keyword><style  face="normal" font="default" size="100%">pollution</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil microbial biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil respiration</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1995</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1995///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/026974919400041B</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">7491</style></volume><pages><style face="normal" font="default" size="100%">81 - 87</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Decomposition of oak (Quercus ilex) leaves containing different concentrations of Fe, Zn, Cu, Cr, Ni and Pb was measured in laboratory microcosms. The leaves were collected from a polluted site inside the city of Naples and from a control site away from the city. Soil was sampled from the upper A horizon (0-5 cm) at both sites and analyzed for respiration, microbial biomass and abundance of fungal mycelia. The soils from the two sites differed significantly in heavy metals concentrations. The accumulated mass loss reached an asymptotic value after four months both for the control and polluted litters. However, control and polluted litters significantly differed in accumulated mass loss, that was respectively 40 % and 29 % of the initial weight, after 10 months. Moreover decomposition rates appeared to be strongly influenced by metal contamination in the early stages, while in later stages, they did not differ significantly. Litter respiration appeared to be inhibited by metal contamination and showed pattern and rates consistent with those found for litter decomposition. Fungal mycelia were significantly less abundant both in litter and soil from the polluted site than from the con- trol site. Metabolic activity (both as soil respiration and degree of mineralization) was lower in the polluted soil. Soil respiration and amount of soil mycelia correlated negatively with soil Pb, Zn and Cr concentration.</style></abstract><issue><style face="normal" font="default" size="100%">April 1990</style></issue></record></records></xml>