tailieunhanh - Báo cáo lâm nghiệp: "An integrated analysis of 33 Eucalyptus trials linking the onset of competition-induced tree growth suppression with management, physiographic and climatic factors"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: An integrated analysis of 33 Eucalyptus trials linking the onset of competition-induced tree growth suppression with management, physiographic and climatic factors. | Ann. For. Sci. 64 2007 585-591 INRA EDP Sciences 2007 DOI forest 2007036 Available online at Original article An integrated analysis of 33 Eucalyptus trials linking the onset of competition-induced tree growth suppression with management physiographic and climatic factors Keith M. LlTTLEa Carol A. R0LAND0a Craig D. M0RRISb a Institute for Commercial Forestry Research PO Box 100281 Scottsville 3209 South Africa b Agricultural Research Council c o University of KwaZulu-Natal PB X01 Scottsville 3209 South Africa Received 20 November 2006 accepted 21 February 2007 Abstract - One of the greatest difficulties associated with controlling competitive vegetation during the establishment of eucalypts relates to the timing and planning of weeding operations. This may be due to site related variability in vegetation species distribution and abundance climatic conditions and methods of site preparation. Using data from 33 eucalypt vegetation management trials multivariate statistical techniques were used to determine whether any climatic physiographic or management related variables could be related to the time taken for competition-induced tree growth suppression to occur. Altitude the method of site preparation burning versus not burning and the interaction between these two factors were significantly related to the timing of tree growth suppression. Regardless of the method of site preparation the onset of competition-induced tree growth suppression occurred earlier at lower altitudes where the vegetation was more diverse and vigorous. At higher altitudes burning appears to stimulate the earlier growth of vegetation reducing the time for competition-induced tree growth suppression to occur. previous land use vegetation management inter-specific competition Résumé - Une analyse intégrée de 33 essais avec des eucalyptus reliant le début de la baisse de croissance due à la competition avec la gestion des peuplements les facteurs physiographiques et .