tailieunhanh - Báo cáo khoa học: "Estimating the foliage area of Maritime pine (Pinus pinaster Aït.) branches and crowns with application to modelling the foliage area distribution in the crown"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Estimating the foliage area of Maritime pine (Pinus pinaster Aït.) branches and crowns with application to modelling the foliage area distribution in the crown. | 73 Ann. For. Sci. 57 2000 73-86 INRA EDP Sciences 2000 Original article Estimating the foliage area of Maritime pine Pinus pinaster Alt. branches and crowns with application to modelling the foliage area distribution in the crown Annabel Portéa Alexandre Bosca Isabelle Championb and Denis Loustaua a INRA Pierroton Station de Recherches Forestières Laboratoire d Ecophysiologie et de Nutrition BP. 45 F-33611 Gazinet Cedex France b INRA Laboratoire de Bioclimatologie BP. 81 F-33833 Villenave d Ornon France Received 26 August 1998 accepted 4 October 1999 Abstract - Destructive measurements of architecture and biomass were performed on 63 trees from three Pinus pinaster stands 5 21 and 26 year-old in order to determine the quantity and distribution of foliage area inside the crown. Allometric equations were developed per site and needle age which allowed to correctly calculate R2 to the foliage area of a branch knowing its basal diameter and its relative insertion height in the crown. Using these equations we estimated total crown foliage area. A non-linear function of tree diameter and tree age was fitted to these data R2 and . On the 5 and 26 year-old stands we combined the branch level models and the architectural measurements to develop probability functions describing the vertical and horizontal foliage area distributions inside the crown. The parameters of the beta functions varied with needle and stand age foliage being located mostly in the upper and outer part of the crown for the adult tree whereas it was more abundant in the inner and lower parts of the crown in the 5 year-old trees. A simple representation of crown shape was added to the study so that knowing tree age and diameter it could be possible to fully describe the quantity of foliage area and its localisation inside a maritime pine crown. maritime pine foliage area foliage distribution allometric relationship Résumé - Estimation de la surface foliaire de branches et de houppiers