University of Michigan
Enrollment Year: 2003
Email Address: kmcguire at barnard.edu
Atmospheric Mentor: Mary Anne Carroll, University of Michigan
Biosphere Mentor: John Vandermeer, University of Michigan
Effects of Elevated Atmospheric Nitrogen and Wet Nitrogen Deposition on Mycorrhizal Fungi: Increases in anthropogenic N emissions to the atmosphere have caused elevated levels of N deposition, although the ultimate fate of atmospheric N and the precise effects of these changes on biopsheric activity are still unclear. There is some evidence that increased N depositions disrupts mycorrhizal associations between plants and fungi, but few studies document these effects in forest tree species, despite the ubiquitous dependence of trees on mycorrhial fungi for nutrient acquisition. We propose to investigate the effects of elevated atmospheric N and wet N deposition on mycorrhizal associations in a forest tree species, to enhance our capacity to predict future shifts in forest communities as a result of anthropogenic N additions to the environment. This project seeks to test the hypothesis that elevated atmospheric N and N deposition decrease microbial biomass and respiration in the sugar maple dominated forest ecosystem, by disrupting and shifting species composition of arbuscular mycorrhizal fungi, which are known to extensively colonize the roots of sugar maple trees. The effects of wet N deposition on mycorrhizae will be investigated using long-term N amended and control plots located west of UMBS. The effects of elevated atmospheric N on mycorrhizae will be determined using a chamber experiment with isotopically labeled gaseous nitrogen species.
Krista's Current Work
Krista is currently an Assistant Professor at Barnard College, Columbia University. Her research focuses on:
1)How plant diversity determines the diversity and function of decomposer fungi across latitudes
2)How mycorrhizal associations influence the distribution and diversity patterns of trees in tropical rain forests
3) how global changes impact microbial communities and plan-fungal interactions.
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