tailieunhanh - Báo cáo khoa học: "Interactive effects of waterlogging and irradiance on the photosynthetic performance of seedlings from three oak species displaying different sensitivities (Quercus robur, Q petraea and Q rubra)"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Interactive effects of waterlogging and irradiance on the photosynthetic performance of seedlings from three oak species displaying different sensitivities (Quercus robur, Q petraea and Q rubra)". | Ann Sci For 1997 54. 409-429 Elsevier Inra 409 Original article Interactive effects of waterlogging and irradiance on the photosynthetic performance of seedlings from three oak species displaying different sensitivities Quercus robur Qpetraea and Q rubra PA Wagner1 E Dreyer2 Equipe sol et nutrition 2Équipe bioelmatologie-écophysioloịỊÌe. Unite écophysioloỊiie forestiere Inra-Nancy 54280 Chainpenoux France. Received 4 October 1996 accepted 2 January 1997 Summary - Potted seedlings from three oak species Quercus robin Q petraea and Q rubra . known to present different sensitivities to temporary soil hypoxia were submitted to two contrasted irradiance regimes in a greenhouse 100 and approximately 35 of full greenhouse irradiance and shortly after to waterlogging for 2-4 weeks. The experiment was repeated for 2 years. Leaf gas exchange chlorophyll content and fluorescence leaf water potential and photosynthetic capacity were recorded several times during the stress. Biomass increment was estimated at the end of the stress or after 3 weeks of drainage. Despite its late application after completion of elongation and expansion of leaves shading significantly reduced growth and modified photosynthetic activity. It generally reduced net assimilation rates and increased chlorophyll contents. Q rubra seedlings behaved differently growth decreased and chlorophyll was enhanced as in the two other species but net assimilation rates and photosynthetic capacity were higher in the shade than under full irradiance. This surprising effect probably resulted from high irradiance stress and was not alleviated by improved fertilization during the second year. Waterlogging induced severe disorders in photosynthesis net co assimilation stomatai conductance photosynthetic capacity chlorophyll content and growth declined In addition predawn values of photochemical efficiency of photosystem II which are usually close to the optimum value of were significantly decreased. The largest .