Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài:"Competition for water between beech seedlings and surrounding vegetation in different light and vegetation composition conditions" | Ann. For. Sci. 60 2003 593-600 INRA EDP Sciences 2004 DOI forest 2003051 593 Original article Competition for water between beech seedlings and surrounding vegetation in different light and vegetation composition conditions Lluis COLLa Philippe BALANDIERa Catherine PiCON-COCHARDb Bernard PRÉVOSTOa Thomas CuRTa a CEMAGREF - . DFCF Applied Ecology of Woodlands Research Team 24 avenue des Landais BP 50085 63172 Aubière Cedex France b INRA - . Agronomie 234 avenue du Brezet 63039 Clermont-Ferrand France Received 24 June 2002 accepted 10 February 2003 Abstract - To gain a better understanding of beech growth requirements and assess the competition with the surrounding vegetation at two successional stages after agricultural land abandonment we introduced two-year-old beech seedlings i in a recently abandoned meadow one half weeded and ii in an old meadow colonised by 25-year-old natural Scots pine with one part thinned to increase light availability at ground level. Beech seedlings presented significantly different stem diameter growth rates according to vegetation composition grasses or dicotyledon species and light availability for both successional stages. Grass species which developed efficient strategies to extract soil water competed strongly with beech seedling compared with dicotyledon species. Water competition led to a strong reduction of beech diameter growth. For a given vegetation composition increasing light availability improved beech growth. competition Fagus sylvatica L. understorey vegetation grasses root development soil water content Resume - Compétition pour l eau entre de jeunes hêtres et la végétation environnante en fonction du niveau de lumière et de la composition de la végétation. Afin de mieux comprendre les conditions de croissance du hêtre et d evaluer l impact de la competition par la vegetation à deux stades de la succession végétale après abandon de terres agricoles des plants de hêtre de deux ans ont été introduits i dans