Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Biomass and nutrient cycling of a highly productive Corsican pine stand on former heathland in northern Belgium. | Ann. Sci. For. 55 1998 389-405 Inra Elsevier Paris 389 Original article Biomass and nutrient cycling of a highly productive Corsican pine stand on former heathland in northern Belgium Johan Neiryncka Danny Maddeleinb Luc de Keersmaekera Noel Lusta Bart Muysc a Laboratory of Forestry University of Ghent Geraardsbergsesteenweg 267 9090 Gontrode Belgium b Flemish Forest Service AMINAL Belliardstraat 14 - 18 1040 Brussels Belgium c Laboratory of Forest Nature and Landscape Research Catholic University of Leuven Vital Decosterstraat 102 3000 Leuven Belgium Received 14 April accepted 22 September 1997 Abstract - Biomass and nutrient cycling were examined in a 62-year-old highly productive Corsican pine stand Pinus nigra Am. ssp. laricio Poiret growing on a coarse and dry sandy soil with low exchangeable nutrient pools. Total aboveground biomass was estimated at 240 tons dry weight per hectare of which 201 tons concerned boles. The belowground biomass amounted to 461 ha-1 16 of total standing biomass . The current annual volume increment was estimated at m3 ha 1 year1. Root study emphasized the role of the rooting depth as an important growth factor. Calculated uptake rates for N p K Ca and Mg were respectively 1 9 and kg ha 1 year1. Despite an abundant nitrogen deposition 46 kg inorg. N ha 1 year-1 between 23 and 35 of the nitrogen demand was supplied by internal transfers. Retranslocation of phosphorus fulfilled 64 of the annual requirement. The root uptake of potassium calcium and magnesium were better coupled with the tree requirements. The uptake rates of Ca and Mg could be met by atmospheric deposition. The canopy leaching of potassium accounted for 70 of the root uptake. The low uptake rates of p Ca and Mg were inconsistent with the vigorous growth of the stand which could only be maintained by a high nutrient use efficiency. The monitoring of the nutrient status between 1988 and 1995 revealed an obvious decline in the concentrations of Ca .
