Basiliko, Nathan

Full Research Description:
Terrestrial biogeochemistry and soil microbial ecology; climate and environmental change; ecosystem restoration and sustainability
Soil microorganisms play vital, yet poorly characterized roles in terrestrial ecosystems. My work explores the microbial role in wetland and forest biogeochemistry. In particular I focus on microbial responses to human-induced environmental changes that have consequences for greenhouse gas fluxes, nutrient and carbon dynamics, and ecosystem sustainability. Recently I have also developed interest in exploring more general controls on microbial diversity in soils, links between diversity and activity, and am interested in how different soil microbial communities transform plant tissues into soil organic matter and then subsequently decompose this organic matter to mineral products, including greenhouse gases. Our understanding of soil microbiology relevant to larger-scale ecosystem dynamics has grown tremendously in the past 15 years. This is a result of the development and refinement of rapid molecular ecological techniques for studying complex soil microbial communities and a realization that understanding controls on microbial dynamics in terrestrial ecosystems is essential to understanding how the biosphere will respond to unprecedented climate and environmental change and natural resource management.

Wetlands
Northern peat-forming wetlands (peatlands) are large sinks for atmospheric carbon dioxide (CO2) and sources of atmospheric methane (CH4), thus playing an important role in the greenhouse effect and global climate. There is particular interest to understand how climate and environmental change will affect greenhouse gas dynamics in these sites. In peatlands CO2 is sequestered as a net imbalance between plant productivity and microbial decomposition. Decomposition is particularly slow in part because of cold temperatures, lack of nutrients, waterlogged anaerobic conditions, and the rather anti-microbial nature of the vegetation. Methane emissions from peatlands occur as the balance between the activities of 2 groups of microorganisms: anaerobic methanogenic archaea and aerobic methane oxidizing bacteria. My research in these sites focuses principally on the microbial control of carbon and nutrient cycling in peatlands with the objective of understanding what controls microbial community dynamics in these sites and it turn how these dynamics relate to patterns of CO2 and CH4 fluxes. A large portion of my research is devoted to characterizing how these relationships are affected by human induced climate, environmental, and land-use change.

Forests
Canada contains 10 percent of the world's forests and is the largest exporter of forest products. Forests also contain a large stock of organic carbon that would otherwise contribute to the global greenhouse effect as CO2 in the atmosphere, upland forest soils are sinks for atmospheric CH4, and occasionally forest soils are sources of the greenhouse gas nitrous oxide. There is interest to preserve ecosystem functioning in managed sites to promote rapid and successful tree regrowth to maintain resource supply and for better environmental stewardship. Soil microorganisms control the often-limited nutrient supply in forests through decomposition of detritus and fixation. Harvesting practices that maintain soil microbial communities and functioning may result in more resilient, sustainable systems. My work involves linking microbial ecology to nutrient and carbon cycling and determining the degree to which forestry practices and climate and environmental change alter forest soil microbial activities and diversity.