<?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%">Ceacero, Carlos J</style></author><author><style face="normal" font="default" size="100%">Díaz-Hernández, José Luis</style></author><author><style face="normal" font="default" size="100%">del Campo, Antonio D</style></author><author><style face="normal" font="default" size="100%">Navarro-cerrillo, Rafael M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Interactions between soil gravel content and neighboring vegetation control management in oak seedling establishment success in Mediterranean environments</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%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Rock fragment</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword><keyword><style  face="normal" font="default" size="100%">Vegetation establishment</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><publisher><style face="normal" font="default" size="100%">Elsevier B.V.</style></publisher><volume><style face="normal" font="default" size="100%">271</style></volume><pages><style face="normal" font="default" size="100%">10-18</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Restoration of vegetation in Mediterranean areas is limited by several factors, some of which are poorly understood, such as soil stoniness and competition with natural vegetation. This paper analyzes the interaction between weed management treatments (cultivation, herbicide, mulch and tree shelter) and the proﬁle stoniness in Holm oak (Quercus ilex L. sub. ballota (Desf.) Samp.) seedling establishment in Mediterranean areas. Our experimental trials show that proﬁle gravel content is a key factor in seedling survival, in which optimal reforestation sites would be deﬁned by gravel content &lt;5%; transitional sites by 5% 6 gravel content 6 15% and excluded sites by gravel content &gt;15%. The soil proﬁle gravel content caused severe water limitations, especially important in the ﬁrst year after planting, which inﬂuenced the effectiveness of neighboring vegetation control techniques for seedling establishment success. This study also conﬁrms the positive effect of competition management techniques on survival. The treatments tested showed an improvement in the survival rate, but not in growth rate, over the control treatment throughout the monitoring period. We have obtained a vegetation response model in which the beneﬁcial effects of competition control on the success of oak seedling establishment are distorted by soil gravel content.</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%">Inclán, Rosa</style></author><author><style face="normal" font="default" size="100%">Uribe, Carla</style></author><author><style face="normal" font="default" size="100%">Sánchez, Laura</style></author><author><style face="normal" font="default" size="100%">Sánchez, Dolores M.</style></author><author><style face="normal" font="default" size="100%">Clavero, Ángeles</style></author><author><style face="normal" font="default" size="100%">Fernández, Ana María</style></author><author><style face="normal" font="default" size="100%">Morante, Ramón</style></author><author><style face="normal" font="default" size="100%">Blanco, Alfredo</style></author><author><style face="normal" font="default" size="100%">Jandl, Robert</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">N2O and CH4 fluxes in undisturbed and burned holm oak, scots pine and pyrenean oak forests in central Spain</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%">á</style></keyword><keyword><style  face="normal" font="default" size="100%">fire</style></keyword><keyword><style  face="normal" font="default" size="100%">greenhouse flux á fire</style></keyword><keyword><style  face="normal" font="default" size="100%">Greenhouse ﬂux</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%">quercus pyrenaica á pinus</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">soil temperature á</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword><keyword><style  face="normal" font="default" size="100%">soil water content á</style></keyword><keyword><style  face="normal" font="default" size="100%">sylvestris á</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/s10533-010-9520-8http://link.springer.com/10.1007/s10533-010-9520-8</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">107</style></volume><pages><style face="normal" font="default" size="100%">19 - 41</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We investigated N2O and CH4 ﬂuxes from soils of Quercus ilex, Quercus pyrenaica and Pinus sylvestris stands located in the surrounding area of Madrid (Spain). The ﬂuxes were measured for 18 months from both mature stands and post ﬁre stands using the static chamber technique. Simultaneously with gas ﬂuxes, soil temperature, soil water content, soil C and soil N were measured in the stands. Nitrous oxide ﬂuxes ranged from -11.43 to 8.34 lg N2O–N m -2 h -1 in Q.ilex, -7.74 to 13.52 lg N2O–N m -2 h -1 in Q. pyrenaica and -28.17 to 21.89 lg N2O–N m -2 h -1 in P. sylvestris. Fluxes of CH4 ranged from -8.12 to 4.11 lg CH4– C m -2 h -1 in Q.ilex, -7.74 to 3.0 lg CH4 –C m -2 h -1 in Q. pyrenaica and -24.46 to 6.07 lg CH4–C m -2 h -1 in P. sylvestris. Seasonal differences were detected; N2O ﬂuxes being higher in wet months whereas N2O ﬂuxes declined in dry months. Net consumption of N2O was related to low N availability, high soil C contents, high soil temperatures and low moisture content. Fire decreased N2O ﬂuxes in spring. N2O emissions were closely correlated with previous day’s rainfall and soil moisture. Our ecosystems generally were a sink for methane in the dry season and a source of CH4 during wet months. The available water in the soil inﬂuenced the observed seasonal trend. The burned sites showed higher CH4 oxidation rates in Q. ilex, and lower rates in P. sylvestris. Overall, the data suggest that ﬁre alters both N2O and CH4 ﬂuxes. However, the magnitude of such variation depends on the site, soil characteristics and seasonal climatic conditions.</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%">Urbieta, Itziar R</style></author><author><style face="normal" font="default" size="100%">Pérez-Ramos, Ignacio M</style></author><author><style face="normal" font="default" size="100%">Zavala, MIGUEL a</style></author><author><style face="normal" font="default" size="100%">Marañón, Teodoro</style></author><author><style face="normal" font="default" size="100%">Kobe, Richard K</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil water content and emergence time control seedling establishment in three co-occurring Mediterranean oak species</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%">Mediterranean oak species</style></keyword><keyword><style  face="normal" font="default" size="100%">Modelling</style></keyword><keyword><style  face="normal" font="default" size="100%">seed germination</style></keyword><keyword><style  face="normal" font="default" size="100%">seedling emergence</style></keyword><keyword><style  face="normal" font="default" size="100%">seedling survival (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year></dates><publisher><style face="normal" font="default" size="100%">NRC Research Press</style></publisher><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">2382-2393</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Tree species can differ in their responses to resource availability during the critical phase of establishment, which could influence forest dynamics. In Mediterranean forests, most of the attention has focused on the effects of shade and summer drought on seedling survival, but little is known about the effect of autumn to spring rains on earlier stages of recruitment. A sowing experiment was set up along natural light and water gradients with three co-occurring oak species (Quercus suber L. (cork oak), Quercus canariensis Willd. (Algerian oak), and Quercus pyrenaica Willd. (Pyrenean oak)) that show limited natural regeneration in southern Spain. Recruitment stages were monitored for 1 year. Models of seed germination, seedling emergence, and seedling survival as well as of overall recruitment patterns were developed as functions of light, soil moisture, and soil compaction. The influence of intraspecific variation in seed mass and emergence time were also tested. Excess soil water levels during the winter reduced germination and emergence and lengthened time to emergence (in waterlogged open areas), which in turn decreased seedling survival during the dry season. Seedlings from larger seeds were more likely to germinate and emerge. The results suggest that temporal and spatial variability of soil water content, mediated by emergence time and seed size, play a crucial role in the regeneration dynamics of Mediterranean oak forests.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1139/X08-089</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1139/X08-089</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Urbieta, Itziar R.</style></author><author><style face="normal" font="default" size="100%">Pérez-Ramos, Ignacio M.</style></author><author><style face="normal" font="default" size="100%">Zavala, Miguel A.</style></author><author><style face="normal" font="default" size="100%">Marañón, Teodoro</style></author><author><style face="normal" font="default" size="100%">Kobe, Richard K.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Soil water content and emergence time control seedling establishment in three co-occurring Mediterranean oak species</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%">Mediterranean oak species</style></keyword><keyword><style  face="normal" font="default" size="100%">Modelling</style></keyword><keyword><style  face="normal" font="default" size="100%">seed germination</style></keyword><keyword><style  face="normal" font="default" size="100%">seedling emergence</style></keyword><keyword><style  face="normal" font="default" size="100%">seedling survival (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</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/10.1139/X08-089</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">38</style></volume><pages><style face="normal" font="default" size="100%">2382 - 2393</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Tree species can differ in their responses to resource availability during the critical phase of establishment, which could influence forest dynamics. In Mediterranean forests, most of the attention has focused on the effects of shade and summer drought on seedling survival, but little is known about the effect of autumn to spring rains on earlier stages of recruitment. A sowing experiment was set up along natural light and water gradients with three co-occurring oak species (Quercus suber L. (cork oak), Quercus canariensis Willd. (Algerian oak), and Quercus pyrenaica Willd. (Pyrenean oak)) that show limited natural regeneration in southern Spain. Recruitment stages were monitored for 1 year. Models of seed germination, seedling emergence, and seedling survival as well as of overall recruitment patterns were developed as functions of light, soil moisture, and soil compaction. The influence of intraspecific variation in seed mass and emergence time were also tested. Excess soil water levels during the winter reduced germination and emergence and lengthened time to emergence (in waterlogged open areas), which in turn decreased seedling survival during the dry season. Seedlings from larger seeds were more likely to germinate and emerge. The results suggest that temporal and spatial variability of soil water content, mediated by emergence time and seed size, play a crucial role in the regeneration dynamics of Mediterranean oak forests.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><notes><style face="normal" font="default" size="100%">doi: 10.1139/X08-089doi: 10.1139/X08-089The 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%">Cubera, Elena</style></author><author><style face="normal" font="default" size="100%">Moreno, Gerardo</style></author><author><style face="normal" font="default" size="100%">Elena, C.</style></author><author><style face="normal" font="default" size="100%">Gerardo, M.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of single Quercus ilex trees upon spatial and seasonal changes in soil water content in dehesas of central western Spain</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%">Oak woodland</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword><keyword><style  face="normal" font="default" size="100%">TDR</style></keyword><keyword><style  face="normal" font="default" size="100%">tree-grass interaction</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/10.1051/forest:2007012</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">64</style></volume><pages><style face="normal" font="default" size="100%">355 - 364</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The spatial and temporal evolution of soil water content () in Quercus ilex dehesas has been investigated to determine how trees modify the soil water dynamics and the nature of tree-grass interactions in terms of soil water use in these ecosystems. Soil physical parameters and were measured at different distances from the tree trunk (2-30 m) in the upper 300 cm of soil. was measured monthly by TDR during 2002-2005. Tree water potential was determined during the summers of 2004 and 2005. At deeper soil layers, mean values were higher beyond than beneath tree canopy during dry periods. depletion beyond tree canopy continued even in summer, when herbaceous plants dried up, suggesting that trees uptake water from the whole inter-tree space. Results have shown a high dependence of trees on deep water reserves throughout late spring and summer, which helps to avoid competition for water with herbaceous vegetation.</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%">Cubera, Elena</style></author><author><style face="normal" font="default" size="100%">Moreno, Gerardo</style></author><author><style face="normal" font="default" size="100%">Elena, C</style></author><author><style face="normal" font="default" size="100%">Gerardo, M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Effect of single Quercus ilex trees upon spatial and seasonal changes in soil water content in dehesas of central western Spain</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%">Oak woodland</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword><keyword><style  face="normal" font="default" size="100%">TDR</style></keyword><keyword><style  face="normal" font="default" size="100%">tree-grass interaction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><volume><style face="normal" font="default" size="100%">64</style></volume><pages><style face="normal" font="default" size="100%">355-364</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The spatial and temporal evolution of soil water content () in Quercus ilex dehesas has been investigated to determine how trees modify the soil water dynamics and the nature of tree-grass interactions in terms of soil water use in these ecosystems. Soil physical parameters and were measured at different distances from the tree trunk (2-30 m) in the upper 300 cm of soil. was measured monthly by TDR during 2002-2005. Tree water potential was determined during the summers of 2004 and 2005. At deeper soil layers, mean values were higher beyond than beneath tree canopy during dry periods. depletion beyond tree canopy continued even in summer, when herbaceous plants dried up, suggesting that trees uptake water from the whole inter-tree space. Results have shown a high dependence of trees on deep water reserves throughout late spring and summer, which helps to avoid competition for water with herbaceous vegetation.</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%">SÁNCHEZ, M E</style></author><author><style face="normal" font="default" size="100%">Andicoberry, S</style></author><author><style face="normal" font="default" size="100%">TRAPERO, A</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Pathogenicity of three Phytophthora spp. causing late seedling rot of Quercus ilex ssp. ballota</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Pathology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Nurseries (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Phytophthora spp.</style></keyword><keyword><style  face="normal" font="default" size="100%">root rot</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2005</style></year></dates><publisher><style face="normal" font="default" size="100%">Blackwell Verlag GmbH</style></publisher><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">115-125</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Within a research project on quality of plants for forestation of agricultural lands, we studied the aetiology of a late seedling rot affecting holm oak (Quercus ilex ssp. ballota) in two forest nurseries in southern Spain. Major disease symptoms were foliage wilting and necrosis of feeder roots. Phytophthora cinnamomi, Phytophthora cryptogea and Phytophthora drechsleri were isolated from necrotic roots of holm oaks. Selected isolates of the three Phytophthora species were pathogenic to Quercus ilex ssp. ballota and Quercus suber seedlings in artificial inoculations. Soil flooding conditions were essential for infection and root rot development. There was no host specificity among the species, the isolates of P. cinnamomi being the most virulent in all inoculated plants. In these inoculations, Q. ilex ssp. ballota plants were more susceptible than those of Q. suber. This work is the first report of P. cinnamomi, P. drechsleri and P. cryptogea affecting Q. ilex ssp. ballota in forest nurseries.</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%">Sanchez, M. E.</style></author><author><style face="normal" font="default" size="100%">Andicoberry, S.</style></author><author><style face="normal" font="default" size="100%">Trapero, A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Pathogenicity of three Phytophthora spp. causing late seedling rot of Quercus ilex ssp. ballota</style></title><secondary-title><style face="normal" font="default" size="100%">Forest Pathology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Holm oak</style></keyword><keyword><style  face="normal" font="default" size="100%">Nurseries (voyant)</style></keyword><keyword><style  face="normal" font="default" size="100%">Phytophthora spp.</style></keyword><keyword><style  face="normal" font="default" size="100%">root rot</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</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/10.1111/j.1439-0329.2004.00392.x</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">115 - 125</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Within a research project on quality of plants for forestation of agricultural lands, we studied the aetiology of a late seedling rot affecting holm oak (Quercus ilex ssp. ballota) in two forest nurseries in southern Spain. Major disease symptoms were foliage wilting and necrosis of feeder roots. Phytophthora cinnamomi, Phytophthora cryptogea and Phytophthora drechsleri were isolated from necrotic roots of holm oaks. Selected isolates of the three Phytophthora species were pathogenic to Quercus ilex ssp. ballota and Quercus suber seedlings in artificial inoculations. Soil flooding conditions were essential for infection and root rot development. There was no host specificity among the species, the isolates of P. cinnamomi being the most virulent in all inoculated plants. In these inoculations, Q. ilex ssp. ballota plants were more susceptible than those of Q. suber. This work is the first report of P. cinnamomi, P. drechsleri and P. cryptogea affecting Q. ilex ssp. ballota in forest nurseries.</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 Verlag GmbH</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%">Joffre, Richard</style></author><author><style face="normal" font="default" size="100%">OURCIVAL, JEAN-MARC</style></author><author><style face="normal" font="default" size="100%">Rambal, Serge</style></author><author><style face="normal" font="default" size="100%">ROCHETEAU, ALAIN</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The key-role of topsoil moisture on CO$_2$ efflux from a Mediterranean Quercus ilex forest</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%">CO2 efflux</style></keyword><keyword><style  face="normal" font="default" size="100%">ecosystem respiration</style></keyword><keyword><style  face="normal" font="default" size="100%">Mediterranean ecosystem</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil temperature</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2003</style></year></dates><volume><style face="normal" font="default" size="100%">60</style></volume><pages><style face="normal" font="default" size="100%">519-526</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">CO2 respiratory losses partly determine net carbon ecosystem exchanges. The main objective of this paper was to understand regulation imposed by soil water content and temperature on soil and ecosystem CO2 efflux in a holm oak (Quercus ilex L.) Mediterranean forest. Soil CO2 efflux was monitored monthly during 1999 and 2001. Moreover, experimental water treatments were conducted in 1999 over 9 small plots (0.3 m2) during nine months. Results showed strong decreases of soil CO2 efflux for a relative soil water content below 0.7. Ecosystem respiration measured by eddy covariance over a 4-year period showed strong sensitivity to soil water content and temperature. Severe limitations of soil and ecosystem efflux imposed by low values of soil water content occurred on about 90 days per year. The best adjustments of soil and ecosystem CO2 efflux were obtained using regression models where the exponential effect of temperature is linearly related to soil water content ( r2 = 0.68 and 0.79 for soil and ecosystem respectively). Our results highlighted strong differences in respiration sensitivity to topsoil moisture between soil and ecosystem. When the relative water content (RWC) is low (0.4), an increase of 1 °C provokes an increase of soil respiration of 5.7% and an increase of ecosystem respiration of 8.6%. For nonlimiting soil water conditions, at RWC = 1, the increases of respiration caused by a 1 °C temperature increase are of 8.5% and 16.5% for soil and ecosystem respectively. These results emphasized the probable determinant influences of changes in soil water regime for respiratory fluxes and net carbon exchanges of Mediterranean forest ecosystems.</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%">López, Bernat</style></author><author><style face="normal" font="default" size="100%">SABATE, Santiago</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%">Fine roots dynamics in a Mediterranean forest: effects of drought and stem density</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">holm oaks</style></keyword><keyword><style  face="normal" font="default" size="100%">minirhizotron</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus ilex</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil water content</style></keyword><keyword><style  face="normal" font="default" size="100%">thinning</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">601-606</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Summer drought is a characteristic trait of Mediterranean climates and can limit primary production. The holm oak (Quercus ilex L.) forest at the Prades Experimental Complex of Catchments (PECC, NE Spain) was managed by clearcutting until the 1950s. As a result of this practice, the forest has a high density (13000 stems ha−1) that is causing growth stagnation and intense competition for water. A thinning experiment was conducted to release resources, reduce stem competition and improve forest productivity. Minirhizotrons were installed in two plots in each of the thinned and control stands and fine root dynamics quantified to a soil depth of 60 cm over a 2-year period (June 1994–May 1996).Soil water content was higher and soil water penetrated deeper in the soil (30–50 cm) in the thinned plots than in the control plots. In the control plots, soil temperature did not vary substantially with depth (mean = 11.65 °C), whereas soil temperature was higher in shallow horizons compared with deep horizons in the thinned plots. Mean soil temperature was one degree higher in the thinned plots than in the control plots (12.9 versus 11.9 °C). There were always more roots in the top 20 cm of soil in thinned plots than in control plots. In the thinned plots, more than 50% of root density (root no. cm−2) was located in the top 20 cm of soil, whereas root density never reached 50% in the 0–20 cm soil layer of the control plots. Roots longevity varied from 35 to 471 days, and there were significant differences between soil depths. Root longevity was greater in the control plots than in the thinned plots.</style></abstract><notes><style face="normal" font="default" size="100%">10.1093/treephys/18.8-9.601</style></notes><research-notes><style face="normal" font="default" size="100%">10.1093/treephys/18.8-9.601</style></research-notes></record></records></xml>