Productivity, carbon sequestration, and diversity of the central boeal forest in changing environments

了解植物相互作用、森林发展和环境因素对森林生产力、碳固存和多样性的影响，对于加拿大制定适应不断变化的环境的战略至关重要。在过去的5年里，我的研究项目主要集中在林分结构和林下植被的动态，森林演替，以及营林强度对中部北方混交林的森林生产力、结构和组成的影响。未来5年的总体目标是：(1)进一步研究物种混合对地上和地下生产力的影响，以检验生态位互补和竞争促进转移的假说，以及对植物多样性的影响，以检验资源量和异质性假说；(2)通过调查地上和地下生产过程，进一步研究林分动态，以检验生产力和固碳峰值是否在中间林龄，老生长林是碳源还是碳汇，以及地下生产力和固碳是否反映了地上动态；(3)研究北方森林对全球气候变化的响应，通过测试中央北方森林中颤杨、白桦、马尾松、黑云杉和白云杉的树高和直径生长在过去两个世纪中是否随着全球气温和大气CO2浓度的增加而增加，是否在高纬度出现更大的增长，以及不同物种的反应是否不同。拟议的计划将包括培训现有的学生和助理(6名博士、4名硕士、2名PDF、2名客座教授和2名技术人员)和另外13名(5名博士、5名本科生和5名助理)。结果将在各种媒体上发表，包括同行评议的期刊、论文、会议和研讨会。进一步加深对北方中部森林生产力、固碳和多样性动态过程的了解，将有助于制定更好的森林管理战略，以应对全球气候变化。

Understanding the effects of plant interaction, forest development, and environmental factors on forest productivity, carbon sequestration, and diversity is crucial for Canada to develop adaptation strategies for a changing environment. During the past 5 yrs, my research program has focused on dynamics of stand structure and understory vegetation, forest succession, and the influences of silvicultural intensity on forest productivity, structure, and composition of the central boreal mixedwood forest. The overall objectives of the proposed research for the next 5 yrs are to: (1) further examine species mixture effects on above- and belowground productivity to test the hypotheses of niche complementarity and competition-facilitation shift, and on plant diversity to test resource quantity and heterogeneity hypothesis; (2) further study stand dynamics by investigating above- and belowground production processes to test whether productivity and carbon sequestration peak at intermediate stand age, if old growth forests are a carbon source or sink, and if belowground productivity and carbon sequestration mirror aboveground dynamics; and (3) investigate boreal forest response to global climate change by testing if tree height and diameter growth of trembling aspen, white birch, jack pine, black spruce, and white spruce in the central boreal forest have increased with increasing global temperature and atmospheric CO2 concentration for the past two centuries, if greater increases of growth have occurred in higher latitudes, and if different species have responded differently. The proposed program will involve training existing students and associates (6 PhDs, 4 MScs, 2 PDFs, 2 visiting professors, and 2 technicians) and an additional 13 (5PhD, 5 undergraduates, and 5 assistants). The results will be published in various media including peer-reviewed journals, theses, conferences, and workshops. The further improved understanding of the dynamic processes of productivity, carbon sequestration, and diversity of the central boreal forest will help develop better forest management strategies to cope with global climate changes.