Biodiversity: Kathleen Treseder

April 20, 2011 "Fungal Diversity, Global Change, and Ecosystems" with Kathleen Treseder, Associate Professor of Ecology and Evolutionary Biology, University of California, IrvineAbstract: We are investigating the role of fungi in mediating ecosystem responses to global change. Specifically, we tested for changes in the community composition and function of fungi under global warming, and examined potential consequences for the release of greenhouse gases from the soil. Our goal was to determine whether fungi might form positive or negative feedbacks on global warming. Our studies were conducted in boreal soils in Alaska, where a significant portion of the Earth's carbon is stored. We used quantitative PCR and DNA sequencing to characterize shifts in the abundance and diversity of fungi, and we found that fungal abundance declined while fungal diversity increased. Overall, our findings suggest that in the short term, fungi may form a negative feedback on global warming owing to their decrease in abundance, respiration, and use of recalcitrant organic nitrogen. Over the longer term, however, changes in the fungal community might lead to proliferation of fungal taxa that target lignocellulose, which could ultimately reduce soil carbon storage.

Kathleen Treseder's research examines the role of fungi in mediating ecosystem responses to global change. Along with bacteria and other soil biota, fungi control several critical biogeochemical processes, including plant nutrient acquisition, decomposition of dead biomass, sequestration of nutrients in living and dead fungal tissue, and release of trace gases such as methyl halides. By trying to understand the specific fungal groups involved and their individual responses to the environment, her research tries to predict ecosystem-level responses to environmental variation.

The Biodiversity, Ecology, and Global Change lecture series is sponsored by the Harvard University Center for the Environment with generous support from Bank of America. The lecture will be followed by a reception in the Biolabs lobby.