tailieunhanh - Báo cáo lâm nghiệp: "Variability of initial growth, water-use efficiency and carbon isotope discrimination in seedlings of Faidherbia albida (Del.) A. Chev., a multipurpose tree of semi-arid Africa. Provenance and drought effect"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Variability of initial growth, water-use efficiency and carbon isotope discrimination in seedlings of Faidherbia albida (Del.) A. Chev., a multipurpose tree of semi-arid Africa. Provenance and drought effects. | Ann. Sci. For. 55 1998 329-348 Inra Elsevier Paris 329 Original article Variability of initial growth water-use efficiency and carbon isotope discrimination in seedlings of Faidherbia albida Del. A. Chev. a multipurpose tree of semi-arid Africa. Provenance and drought effects Olivier RoupsarcF Hélène I. Jolya Erwin Dreyerb lCIRAD-Forêt Campus international de Baillarguet BP 5035 34032 Montpellier cedex 01 France bInra-Nancy UR Ecophysiologie forestiere Equipe bioclimatologie et écophysiologie forestiere 54280 Champenoux France. Received 28 May 1997 accepted 21 August 1997 Abstract - The panafrican provenances of Faidherbia albida display contrasting growth and survival rates in semi-arid zones of western Africa when they are compared in multi-local field trials. In order to identify some potential causes for such differences we recorded the genetic variability of ecophysiological traits including water-use efficiency IV and carbon isotope discrimination A in seven provenances from contrasting habitats of western and south-eastern Africa. Provenance and drought effects were tested on potted seedlings in a greenhouse. After 6 months the total dry mass of the well-irrigated seedlings ranged from 31 to 86 g and the total water-use from 8 to 18 kg. Both initial growth and water consumption were strongly correlated with leaf area w displayed a significant inter-provenance variability and exhibited the highest values in the south-east African provenances which were the most vigourous but also presented the poorest survival rates in field trials. It was negatively correlated with the leaf-to-total dry mass ratio LMR and to A. The mild drought significantly reduced gas-exchange rates leaf area growth water-use specific leaf area and A in all provenances. It also increased the intrinsic water-use efficiency A g and the root-to-total dry mass ratio but did not affect w or LMR. No provenance X drought interaction was found in any variable. The initial rate of leaf area .