Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: A model of light interception and carbon balance for sweet chestnut coppice (Castanea sativa Mill.). | 509s Ann. Sci. For. 1989 46 suppl. 509S-511S Forest Tree Physiology E. Dreyer etal. eds. Elsevier INRA A model of light interception and carbon balance for a sweet chestnut coppice Castanea sativa Mill. L. Mordacq and B. Saugier Laboratoire d Ecologie Végétale CNRS URA121 Bât. 362 Université Paris-Sud 91405 Orsay Cedex France Introduction Data have been collected on leaf photosynthesis young tree photosynthesis wood respiration and aerial growth in a sweet chestnut Castanea sativa Mill. coppice for several years after a cut. We designed a model to predict photosynthesis of heterogeneous canopies and wood respiration. The output of the model together with measurements of aerial growth enabled calculation of the amount of carbon allocated to roots. Materials and Methods Leaf photosynthesis has been measured in situ on attached leaves using a laboratory-made assimilation chamber with control of leaf temperature by Peltier elements. The chamber was working as an open system and the leaf temperature was fixed at 24 c. Measurements were made throughout the growing season. Tree photosynthesis was measured in situ on a 1 yr old chestnut tree using a large assimilation chamber m X m X m high built in the laboratory and working as an open system. A high flow of air through the chamber maximum m3-s-1 kept the increase in air temperature within 4 c with respect to the outside Mordacq and Saugier 1989 . Measurements were performed at the end of the growing season during August and September. The assimilation model took into account the heterogeneous structure of the canopy which is necessary during the first years after the cut. Each tree was first considered as being isolated there was no intersection between the foliage of different trees until the end of the first year. The leaves in the model were distributed homogeneously within ellipsoids or fractions of ellipsoids around each stump. The dimensions of the ellipsoids were measured in situ and the trees .
