tailieunhanh - Báo cáo khoa học: "Belowground biomass and nutrient content in a 47-year-old Douglas-fir plantation"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Belowground biomass and nutrient content in a 47-year-old Douglas-fir plantation. | 423 Ann. For. Sci. 58 2001 423-430 INRA EDP Sciences 2001 Original article Belowground biomass and nutrient content in a 47-year-old Douglas-fir plantation Jacques Ranger and Dominique Gelhaye INRA Centre de Nancy Cycles biogéochimiques 54280 Champenoux France Received 17 July 2000 accepted 6 October 2000 Abstract - Biomass and nutrient content of the root system of a Douglas-fir stand were calculated using the regression technique. Nine trees evenly distributed in the girth classes of the stand were felled for measurements and sampling. Results were compared to published data. Statistically significant relationships between tree circumference at m and root biomass or nutrient content were observed. The root biomass was 58 t of dry matter which was 18 of the total stand biomass. A linear model characterized the relationships between aerial and belowground biomass of 38 Douglas-fir stands previously described in the literature. This simple relationship is very useful when using estimates of the aerial biomass of a stand to calculate the carbon storage in the belowground compartment. Nutrient concentration in the belowground compartment was lower than in the aerial biomass. However very fine roots and mycorrhizae were not considered. Contrary to aerial biomass very few published data were found for belowground biomass hindering any generalization for the nutrient content of the belowground compartment. Douglas-fir root system C sequestration nutrient content Résumé - Biomasse et minéralomasse de la partie souterraine d un peuplement de Douglas de 47 ans. La biomasse et le contenu minéral du système racinaire d un peuplement de Douglas ont été estimés au moyen de regressions à partir d un échantillonnage des-tructif portant sur 9 arbres répartis dans toutes les classes de diamètre à 1 30 m du peuplement. Le résultat a été comparé aux données de la littérature. Il existe des relations statistiquement significatives entre le diamètre à 1 30 m d un arbre et sa .