The soil microbial role in northern forests and peatlands

北方森林和泥炭地特别重要，部分原因是它们将大量大气中的二氧化碳作为有机物质储存在土壤中，与大气交换甲烷，并支持林业和泥炭自然资源工业。加拿大是世界上最大的森林产品出口国，拥有世界第二大泥炭地。土壤微生物群落负责土壤温室气体的净释放，同时循环对生态系统生产力至关重要的养分。目前，关于微生物群落在土壤过程中的作用仍有很多未知，这导致我们对生态系统行为的理解存在不确定性。本研究的目的是利用新的分子和稳定同位素探测技术，结合更经典的方法，将土壤微生物群落与对气候变化和可持续资源管理具有巨大重要性的生态系统过程联系起来。具体来说，这项工作将：1)比较和对比加拿大泥炭地和森林中具有水文和生物地球化学联系的微生物群落和生态系统功能。2)确定包括选择性采伐、间伐、森林施肥、清伐和新的泥炭采伐方法在内的造林处理是否能保护重要的土壤微生物多样性和功能，这些方法将用于在安大略省提取用于替代燃料的泥炭。3)确定特定的微生物群落，随着时间的推移，将植物物质转化为土壤有机质，然后转化为二氧化碳和甲烷。在具有环境干扰的应用环境中，跨生态系统的工作对于改善加拿大的生态系统和资源管理以及提供大的环境梯度以探索土壤微生物生态学的更基本原则将具有重要意义。这些项目将培训研究生和本科生，并为他们提供独特的机会，让他们接触到直接参与安大略省自然资源管理的加拿大政府研究人员，以及国内和国际大学的研究合作者。

Northern forests and peatlands are exceptionally important in part because they store vast amounts of atmospheric carbon dioxide as organic matter in soils, exchange methane with the atmosphere, and support forestry and peat natural resource industries. Canada is the world's largest exporter of forest products and contains the world's second largest peatland area. Soil microbial communities are responsible for the net release of greenhouse gasses from soils and simultaneously cycle nutrients that are essential for ecosystem productivity. Presently there is still a great deal unknown about the role of microbial communities in soil processes and this leads to uncertainties in our understanding of ecosystem behavior. The aim of this research is to use novel molecular and stable-isotope probing techniques, in conjunction with more classical approaches, to link soil microbial communities to ecosystem processes that have vast importance for climate change and sustainable resource management. Specifically this work will: 1) Compare and contrast microbial communities and ecosystem functioning across Canadian peatlands and forests that are hydrologically and biogeochemically connected. 2) Determine if silvicultural treatments including selection harvesting, thinning, forest fertilization, and clearcutting and new peat harvesting methods that will be used for extracting peat for alternative fuel in Ontario preserve important soil microbial diversity and functioning. 3) Identify specific microbial communities that, over time, transform plant material to soil organic matter and then to carbon dioxide and methane. Working across ecosystems, in applied settings with environmental disturbances, will be significant for both improving ecosystem and resource management in Canada and for providing a large gradient of environments to explore more fundamental principles of soil microbial ecology. The projects will train graduate and undergraduate students and provide them unique exposure to Canadian government researchers directly involved in natural resource management in Ontario and to national and international university research collaborators.