The tiny majority: how microbes mediate ecosystem functioning under anthropogenic stressors in boreal environments

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Ecosystem feedbacks to climate change and intensive land use management represent some of the biggest sources of uncertainty in the fate of the future global climate system. Consortia of microorganisms in soils and aquatic sediments are primary players in these feedbacks, responsible for the processing of organic matter and the release of greenhouse gasses. Although the field of environmental microbiology is in a seemingly constant state of exciting technological dynamism, there is still a fundamental disconnect between environmental microbiology and ecosystem ecology. This is in large part because of weaknesses in methods in environmental microbiology that stem from the nature of the small size and high numbers of the targets. Single gene based community fingerprinting methods and environmental genomics have taught us a lot in the past decades, but they also have highlighted that the vast majority of microbes and many classes of microbial genes in the environment are  "known-unknowns". A research program that combines in situ studies of microbial communities and their activities together with targeted-enrichment and isolation approaches offers important promise for progress in understanding how microbial communities dynamically shape our environment. Within this framework, the goals of this proposed work are grouped in to 4 student-led project themes: microbial feedbacks to warming and increased carbon dioxide concentrations across boreal fen peatlands in a globally unique climate change simulation experiment (1), feedbacks to permafrost melt in the 2nd largest peatland complex in the world in the Far North of Ontario (2); the potential loss of microbial diversity and ecosystem functioning under intensified boreal forest harvests for enhanced bioenergy feedstock production (3), and how changing terrestrial plant communities and litter inputs influence carbon and greenhouse gas production in littoral sediments of boreal lakes (4). This transdisciplinary research will address pressing issues in biosphere feedbacks to global climate and land use change, and it will provide scientific guidance for resource management in the era of burgeoning national and international carbon economies. Simultaneously it will strive to enrich for and isolate relevant, unknown microorganisms and characterize fundamentals of their metabolism, physiology, and genetics to help chip away at longstanding constraints in the epistemology of environmental microbiology.