TAILIEUCHUNG - Báo cáo khoa học: "Gas exchange in young Scots pine following pruning of current shoots"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Gas exchange in young Scots pine following pruning of current shoots. | 359 Ann Sci For 1991 48 359-366 Elsevier INRA Original article Gas exchange in young Scots pine following pruning of current shoots ETroeng 1 B Langstrõm 2 Swedish University of Agricultural Sciences Department of Ecology and Environmental Research Box 7072 S-750 07 Uppsala 2 Swedish University of Agricultural Sciences Division of Forest Entomology S-770 73 Garpenberg Sweden Received 8 November 1990 accepted 12 February 1991 Summary A pine shoot beetle attack was simulated by cutting all current shoots in the upper crown of 2 20-yr-old Scots pines Pinus sylvestris L while gas exchange was followed continuously before and after the shoot removal. Net photosynthetic rate and mesophyll conductance of the 2-yr-old shoots decreased by 50 immediately after pruning but recovered within 10 d after the shoot removal. The quantum yield was also much lower after cutting. Water status and transpiration rate were not systematically affected by the treatment. Possible explanations of the photosynthetic decrease could be an accumulation of assimilation products decreasing the mesophyll conductance of carbon dioxide to the chloroplasts or changes of the carbon allocation pattern. Scots pine shoot-pruning I photosynthesis quantum yield field performance Resume Échanges gazeux Chez des jeunes pins Sylvestres après élagage des pousses de I annee. Une attaque du scolytide Tomicus piniperda a été simulée en coupant toutes les pousses de I annee dans la partie supérieure de la couronne de 2 pins Sylvestres Pinus sylvestris L de 20 ans. Pendant le même temps les échanges gazeux ont été suivis de fagon continue avant et après 1 opération. Le taux net de photosynthèse et la conductance du mesophylle des pousses de un an décroĩt d environ 50 immédiatement aprồs 1 élagage mais récupère dans les 10 jours suivant le retrait des pousses. Le rendement quantique diminue aussi beaucoup après la coupe des pousses. L etat hydrique et le taux de transpiration ne sont pas affectes systématiqụement par

• Báo cáo khoa học
• Báo cáo lâm nghiệp hay
• cách trình bày báo cáo
• báo cáo lâm nghiệp
• công trình nghiên cứu lâm nghiệp
• tài liệu về lâm nghiệp