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Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài:" Photosynthetic acclimation of beech seedlings to full sunlight following a major windstorm event in France" | Ann. For. Sci. 60 2003 701-709 INRA EDP Sciences 2004 DOI 10.1051 forest 2003064 701 Original article Photosynthetic acclimation of beech seedlings to full sunlight following a major windstorm event in France Phillip E. REYNOLDSa Henri FROCHOTb a NRCAN Canadian Forest Service 1219 Queen St. East Sault Ste. Marie Ontario Canada P6A 2E5 b Lerfob UMR INRA-ENGREF Growth and Yield Team INRA Centre de Nancy 54280 Champenoux France Received 24 June 2002 accepted 3 August 2003 Abstract - The effect of natural disturbance windthrow of mature forests on photosynthetic acclimation of shade-grown beech Fagus sylvatica L. seedlings was studied at a northeastern France location near Nancy in the Lorraine Region after a major windstorm event in December 1999. Treatments consisted of shaded and full sun plots prior to the storm and plots where beech seedlings were released from shading by the storm. In 2000 beech in released and full sun plots were characterized by similar photosynthesis transpiration mesophyll conductance and water use efficiencies which were generally 2-fold higher than those for beech in shaded plots. Additionally photosynthetic saturation curves did not differ for released and full sun treatments but did differ from the shade treatment. However stomatal conductance values for shaded and released beech did not differ and were lower than those for full sunlight seedlings. Acclimation continued in 2001 but remained incomplete as evidenced by similar intrinsic water use efficiency values for released and shade treatments which were lower than the mean value for the full sun treatment. Plant water potential remained highest for shaded seedlings in both years. These findings suggest that full acclimation is a gradual process occurring over successive growing seasons. We speculate that full acclimation may be directly related to future development of greater root biomass in released seedlings. beech natural disturbance photosynthetic acclimation gas exchange plant .
