Ecosystems on the edge: the ecology of deciduous forest ecosystems near their northern limit in Quebec

边缘生态系统：魁北克北部边界附近的落叶森林生态系统的生态

• 批准号: 36637-2008
• 负责人: Fyles, James
• 金额: $ 1.29万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=390178
• 关键词: Ecosystems; edge; ecology; deciduous; forest

Understanding the factors that control how forest ecosystems function near their northern limits is critical to predicting how forests will respond to climate change. This research aims to increase understanding of the relative role of climate, soil and biotic factors in controlling the distribution of forests dominated by trembling aspen (Populus tremuloides) in the James Bay region of northern Quebec. Our recent work in aspen and black spruce forests in the northern Quebec have shown that establishment and growth of trees depends on the interacting effects of vegetation, soil organic matter decomposition and accumulation, soil nutrition, and site disturbance. We have developed a new approach for multivariate analysis of spatial pattern that improves detection of ecological relationships in the field. The new research will build on these lines of enquiry. The proposed program will study the roles of climate, site, and carbon and nutrient cycling in controlling the distribution of aspen forests across a climatic transect from central Quebec to the northern limit of their range. 'Biocentric' climatic indices will be developed to define the 1300 km transect. Aspen stands will be characterized by tree growth rates, nutrient cycling and soil properties. Patterns of change in these variables with increasing latitude will be compared to patterns of change in climatic indices to test the hypothesis that climate is the dominant control. Since trees respond in an integrated way to multiple stresses, the effect of climate depends on the effects of other factors; favorable conditions in site or soil factors can allow aspen to grow in unfavorable climate. This will be tested in using landscape patterns of aspen forests near their northern limit. We will use C and N isotopic signatures to better gain a better understanding of whether the distribution of aspen forests in changing with changing climate. Overall, the research will increase knowledge of the relative roles of climatic and non-climatic factors in determining the distribution of deciduous forest ecosystems in the north and will provide a better foundation for predicting the effects of climate change.

了解控制森林生态系统在其北部极限附近的影响的因素对于预测森林将如何应对气候变化至关重要。这项研究旨在提高人们对气候，土壤和生物因素在控制魁北克北部詹姆斯湾地区颤抖的阿斯彭（Populus tremuloides）主导的森林分布中的相对作用。我们最近在魁北克北部在阿斯彭和黑色云杉森林中进行的工作表明，树木的建立和生长取决于植被，土壤有机物分解和积累，土壤营养和现场干扰的相互作用。我们已经开发了一种新的方法来对空间模式进行多元分析，以改善该领域的生态关系的检测。新的研究将基于这些探究线。拟议的计划将研究气候，现场和碳和养分循环在控制冬青森林的分布中，从魁北克中部到其范围的北部极限。将开发“以生物为中心”的气候指数来定义1300公里的样带。 Aspen展位的特征是树木生长速率，养分循环和土壤特性。这些变量随纬度增加的变化模式将与气候指数变化模式进行比较，以检验气候是主要控制的假设。由于树木以综合方式对多种压力做出反应，因此气候的影响取决于其他因素的影响。现场或土壤因素中的有利条件可以使Aspen在不利的气候下生长。这将在使用其北部极限附近的阿斯彭森林的景观模式中进行测试。我们将使用C和N同位素特征，以更好地了解asspen森林在随着气候变化而变化时的分布。总体而言，该研究将增加对气候和非气候因素在确定北部落叶森林生态系统分布的相对作用的知识，并将为预测气候变化的影响提供更好的基础。