Effects of climate, disturbance and nitrogen fertilization on the carbon balance of forests in western canada

北温带和北方森林是生物量和土壤碳(C)的大型储存库，对全球光合作用总量做出了重要贡献。重要的是要更好地了解这些碳库对气候变化的响应，研究近年来干扰增加的影响，并制定提高其碳汇强度的管理措施。本研究将在寒带、亚寒带和西海岸温带林分进行。我们的目标是：(1)研究气候变率对生态系统净生产力（NEP）、生态系统总光合作用(P)和生态系统呼吸(R)的影响；(2)量化环境因子、物候和P对R和土壤呼吸（Rs）的影响；(3)异养成分和根际成分之间Rs的分配；(4)评估氮肥对西海岸不同年龄道格拉斯冷杉林分C平衡和N2O排放的影响。(5)确定山松甲虫（MPB）侵袭对亚北方黑松成熟林分碳平衡和水分平衡的影响。

Northern temperate and boreal forests are large reservoirs of biomass and soil carbon (C), and make a major contribution to gross global photosynthesis. It is important to better understand the response of these C pools to climate change, to study the impact of increased disturbance in recent years, and to develop management practices that will enhance their C sink strength. This research will be conducted in boreal, sub-boreal and West Coast temperate forest stands. Our objectives are to (1) study the impact of climatic variability on net ecosystem productivity (NEP), gross ecosystem photosynthesis (P) and ecosystem respiration (R), (2) quantify the effects of environmental factors, phenology and P on R and soil respiration (Rs), (3) partition Rs between its heterotrophic and rhizospheric components, (4) assess the effect of nitrogen fertilization on the C balance and N2O emissions in different-aged West Coast Douglas-fir stands, and (5) determine the impact of mountain pine beetle (MPB) attack on the C and water balances of mature sub-boreal lodgepole pine stands.