Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Effects of a clear-cut on the in situ nitrogen mineralisation and the nitrogen cycle in a 67-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantation. | Ann. For. Sci. 61 2004 397-408 397 INRA EDP Sciences 2004 DOI forest 2004033 Original article Effects of a clear-cut on the in situ nitrogen mineralisation and the nitrogen cycle in a 67-year-old Douglas-fir Pseudotsuga menziesii Mirb. Franco plantation Jean-Hugues Jussy Jacques Ranger Séverine Bienaimé Etienne Dambrine INRA Centre de Nancy Unité Biogéochimie des Écosystèmes Forestiers 54280 Champenoux France Received 5 February 2003 accepted 20 August 2003 Abstract - In situ net nitrogen mineralisation deposition uptake and leaching fluxes were determined in a 67-year-old Douglas-fir Pseudotsuga menziesii Mirb. Franco plantation in the Beaujolais mountains. Measurements were performed during five years before the clear-cut of the stand and two years after the clear-cut. Deposition and mineralisation of N decreased after the harvest. The drastic decrease in tree N uptake was counteracted by the developing understorey vegetation. Microbial immobilisation favoured by the input of organic matter and the increase in temperature was probably the cause of a decrease in the net mineralisation of N. Leaching of mineral N at 15 cm depth decreased after the harvest. However fluxes of Mg and Ca leached at 60 cm depth did not vary after the harvest. nitrogen cycle clear-cut Pseudotsuga menziesii leaching soil Résumé - Effet de la coupe à blanc d une plantation de Douglas Pseudotsuga menziesii Mirb. Franco de 67 ans sur la production in situ d azote minéral et sur le cycle de l azote. La minéralisation nette les dépôts l absorption et le drainage d azote ont été mesurés in situ dans une plantation de Douglas Pseudotsuga menziesii Mirb. Franco de 67 ans située sur sol acide dans les monts du Beaujolais. Les mesures ont été effectuées pendant cinq ans avant la coupe à blanc du peuplement puis pendant 2 ans après la coupe. Les dépôts d azote atmosphérique et la minéralisation de l azote diminuent après la récolte. La diminution du prélèvement d azote par les racines est .
