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、碳封存和多样性的影响，对加拿大制定适应环境变化的战略至关重要。在过去的5年中，我的研究方向主要集中在林分结构和林下植被的动态，森林演替，以及人工林强度对森林生产力、结构和组成的影响。未来5年研究的总体目标是：(1)进一步研究物种混合对地上和地下生产力的影响，以验证生态位互补和竞争促进转变的假设；研究植物多样性，以验证资源数量和异质性的假设；(2)进一步研究林分动态，通过对林分上、地下生产过程的考察，考察林分生产力和固碳量是否在林分中期达到峰值，原生林是碳源还是碳汇，地下生产力和固碳量是否反映地上动态；(3)通过测试近两个世纪以来，北方针叶林中部的颤杨、白桦、短叶松、黑云杉和白云杉的树高和树径是否随着全球气温和大气CO2浓度的升高而增加，高纬度地区是否出现了更大的增长，以及不同树种对全球气候变化的响应是否不同，来研究北方针叶林对全球气候变化的响应。该计划将包括培训现有的学生和同事（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）。研究结果将发表在各种媒体上，包括同行评议的期刊、论文、会议和研讨会。进一步提高对中央寒带森林生产力、碳固存和多样性动态过程的认识，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.