Research

Is carbon from decomposing roots stored in soil longer than carbon from decomposing shoots?

We are tracing 13C carbon from roots and shoots of a ryegrass cover crop as they decompose in a corn field in the Great Lakes Bioenergy Research Center at the Kellog Bioological Research Station. Recent research has suggested that root carbon is stored longer than shoot carbon in soils. Using isotopic tracers we will use field and lab based manipulations to test between multiple mechanisms for long term root carbon storage and what fractions of the soil this carbon is stored in.

This work is funded by a DOE Biological and Environmental Research grant Austin et al., 2017

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How does warming influence fungal communities’ structure and function on decomposing wood?

My graduate research seeks to understand the effects of climatic warming on wood decomposing fungal communities and wood decomposition. My projects include an open-top chamber experiment in collaboration with researchers at UT, NC state, and Harvard Forest, and a laboratory incubation at UT.

This work is funded by an NSF Graduate Research Fellowship.

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Two different species of ectomycorrhizal fungi

We isolated ectomycorrhizal root tips from Pinus virginia specimens and compared the ITS sequences to environmental samples in multiple tree species in North America. Our analysis confirms the identity of Craterellus fungi, C. fallax and C. cornicopioides, which have been thought to be the same species in the past.

Matheny et al., 2010

How will multiple climate change factors influence the community structure of soil bacteria and fungi?

During a post-baccalaureate at Oak Ridge National Laboratory (ORNL), I worked on a project using cloning libraries of rRNA genes (16S and ITS/LSU), to examine changes in community structure of microorganisms under multiple climate change factors. The experiment, Old-field Community Climate and Atmospheric manipulation (OCCAM) manipulated temperature, precipitation and CO2 concentration.

This work is funded by an LDRD (internal ORNL funding). Castro et al. 2010

Research

How does CO2 enrichment influence nitrogen cycling and soil bacterial community structure and function?

During a post-baccalaureate at Oak Ridge National Laboratory (ORNL), I worked on a project using cloning libraries of 16S rRNA genes, extracellular enzyme activity and potential N-mineralization incubations, to examine changes in bacteria community structure and function under CO2 enrichment at the ORNL Free Air CO2 Enrichment (FACE) site.

Austin et al. 2009

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Does soil respiration respond to seasonal variation in temperature and moisture?

During Research Experience for Undergraduates (REU) summer internship at the Harvard Forest, I participated in an experiment taking long term measurements of soil respiration, soil moisture and temperature to associate soil respiration with seasonal variations in temperature and moisture across the landscape.

This work was funded by the NSF REU program.

What percentage of soil respiration is autotrophic (root respiration) vs. heterotrophic (microbial respiration)?

My senior thesis (or Division 3 project) at Hampshire College continued my research from a summer project at the Harvard Forest in which I severed roots from trees of known species, and incubated them at soil temperature to measure respiration rates.