tailieunhanh - Báo cáo lâm nghiệp: "Environmental control of CO assimilation rates 2 and stomatal conductance in five oak species growing under field conditions in Greece"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Environmental control of CO assimilation rates 2 and stomatal conductance in five oak species growing under field conditions in Greece. | Ann Sci For 1996 53 269-278 Elsevier INRA 269 Short note Environmental control of co2 assimilation rates and stomatai conductance in five oak species growing under field conditions in Greece K Radoglou Forest Research Institute Vassilika 57006 Thessaloniki Greece Received 24 October 1994 accepted 15 November 1995 Summary The present study compared co2 assimilation rate and stomatai conductance of five oak species from the beginning of May through November 1993 under similar natural conditions. Gas exchange leaf characteristics and water status were measured on 30-year-old Quercus ilex Q macrolepis Q pedunculiflora Q pubescens and o trojana growing in experimental plots in northern Greece. The seasonal pattern of assimilation rates was similar for all study species but differences occurred between the species. After initial leaf expansion all species rapidly developed high photosynthetic rates. In addition assimilation rates were high in all species in May and November after rain events. No significant differences in stomatai conductance were observed among species during the growing season. The relationships between assimilation rate and stomatai conductance displayed variation in the slopes among species and months. Quercus sp I assimilation rate I stomatai conductance I seasonality drought Resume Effets de I environnement sur I assimilation nette de co2 et la conductance sto-matique de cinq espèces de chênes en plantation en Grèce. Cette étude a permis la comparison des niveaux d assimilation nette de co2 et de conductance stomatique de cinq espèces de chênes en plantation comparative dans le nord de la Grace au cours d une saison de vegetation mai-novembre 1993 . Les échanges gazeux les caractéristlques foliaires et 1 état hydrlque ont été determines sur des arbres de 30 ans de Quercus ilex Q macrolepis Q pedunculiflora Q pubescens et Q trojana. La dynamique saisonnière d assimilation nette était très semblable entre espèces. Des differences slgni-ficatlves sont