tailieunhanh - Báo cáo lâm nghiệp: " Managing diameter growth and natural pruning of Parana pine, Araucaria angustifolia (Bert.) O Ktze., to produce high value timber"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: " Managing diameter growth and natural pruning of Parana pine, Araucaria angustifolia (Bert.) O Ktze., to produce high value timber" | Ann. For. Sci. 62 2005 163-173 INRA EDP Sciences 2005 DOI forest 2005008 163 Original article Managing diameter growth and natural pruning of Parana pine Araucaria angustifolia Bert. O Ktze. to produce high value timber Leif NUTTOa Peter SPATHELFb Robert Rogersc a Avenida da Galicia no 5 Parque Tecnologico da Galicia San Cibrao das Vinas 32901 Ourense Spain b Forstdirektion Tubingen Im Schloss 72074 Tubingen Germany c Forestry Faculty College of Natural Resources University of Wisconsin-Stevens Point Stevens Point Wisconsin 54481 USA Received 13 June 2003 accepted 10 May 2004 Abstract - The objective of the present work was to analyse diameter growth and the relationship of natural pruning and various morphological characteristics of Parana pine Araucaria angustifolia Bert. O Ktze. growing on different sites in southern Brazil and to formulate silvicultural strategies for producing high quality timber for this species. Data on four hundreds trees in both natural and planted forests were collected on temporary sample plots each containing 25 Parana pines. The size of the knotty core within Parana pine stems was modeled with the predictor variables height of the lowest dead branch height to crown base and maximum radial increment of stem at m. The results of our study show that crown width is a good estimator of diameter growth and is closely related to stem diameter at m above ground. Restricting crown expansion such that average annual radial increment is 4 mm year at m for a stem grown for 63 years compared to one grown for 36 years with less crown restriction such that the average annual radial increment is about 75 greater 7 mm year results in a knotty core volume that is about 75 less for the slower growing tree. Managers can use this model to guide silvicultural decisions needed to achieve the production goal of high quality wood of Parana pine. growing space diameter growth high valued timber natural pruning artificial pruning Résumé - .