Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Effect of single Quercus ilex trees upon spatial and seasonal changes in soil water content in dehesas of central western Spain. | Ann. For. Sci. 64 2007 355-364 INRA EDP Sciences 2007 DOI forest 2007012 355 Original article Effect of single Quercus ilex trees upon spatial and seasonal changes in soil water content in dehesas of central western Spain Elena Cubera Gerardo MORENO Departamento de Biología y Producción de los Vegetales Ingeniería Técnica Forestal Universidad de Extremadura Avenida Virgen del Puerto 2 10600 Plasencia Spain Received 30 May 2006 accepted 28 September 2006 Abstract - The spatial and temporal evolution of soil water content 0 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 0 were measured at different distances from the tree trunk 2-30 m in the upper 300 cm of soil. 0 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 0 values were higher beyond than beneath tree canopy during dry periods. 0 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. soil water content TDR Quercus ilex oak woodland tree-grass interaction Résumé - Effets de chênes verts isolés sur les variations spatiales et temporelles de l humidite du sol dans les dehesas du centre-ouest de l Espagne. L objectif de ce travail a été de déterminer les effets de chênes verts Quercus ilex L. isolés sur la teneur en eau du sol 0 et la nature des interactions arbre-strate herbacée sous climat semi-aride en terme d utilisation de l eau du sol dans ces écosystèmes. Les paramètres physiques du sol et 0 ont été mesurés jusqu à 300 cm de profondeur et à différentes distances 2 à .
