Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Influence of shade on photosynthetic gas exchange of 7 tropical rain-forest species from Guadeloupe (French West Indies). | 77 Ann Sà For 1994 51 77-94 Elsevier INRA Original article Influence of shade on photosynthetic gas exchange of 7 tropical rain-forest species from Guadeloupe French West Indies M Ducrey INRA Laboratoire de Recherches Forestieres Méditerranéennes avenue A-Vivaldi F-84000 Avignon France Received 16 November 1992 accepted 21 September 1993 Summary Young seedlings from 7 tropical rain-forest species of Guadeloupe French West Indies Dacryodes excelsa Amanoa caribaea Richeria grandis Simaruba amara Symphonia globu-lifera Byrsonima coriacea and Podocarpus coriaceus were grown for 1 -2 yr in full sunlight or under 4 artificially shaded tunnels transmitting 6 11 19 and 54 daylight. Photosynthetic gas exchanges of attached leaves or branches were then studied in the laboratory. Net photosynthesis-light curves were analysed for an average of 4 seedlings per species and per light treatment. Maximum photosynthesis on a leaf-area basis of sungrown seedlings varied from nmol co2 rrr2 S 1 for Da-cryodes excelsa to nmol co2 m-2 S-1 for Simaruba amara. For all the species studied and when the measurements were expressed on a leaf-area basis maximum photosynthesis of sun-grown seedlings was higher than for shade-grown seedlings. The opposite was observed for photosynthesis under limited light and for apparent quantum yield. We also observed a decrease in maximum photosynthesis and an increase in apparent quantum yield when specific leaf area increased ie when the plants were more shaded. The range of variation in photosynthetic response between full sunlight and full shade made it possible to characterize the photosynthetic plasticity of the species. The results were compared with those obtained for other tropical rain-forest species. They are discussed in terms of photosynthetic and morphological plasticity shade adaptation and of the species place in tropical rain-forest succession. tropical rain forest forest succession shade tolerance net photosynthesis photosynthetic .
