Controls on the formation and persistence of mineral-associated organic matter (MAOM)
I am currently collaborating with Dr. Rich Phillips (Indiana University) and Dr. Jennifer Pett-Ridge (Lawrence Livermore National Lab) to answer key questions about the stability of carbon on soil minerals in ecosystems across the U.S. Using soil collected at sites within the NEON network, we aim to characterize the conditions that favor MAOM formation and understand the potential drivers of its long-term persistence.
Biomass allocation within trees with different mycorrhizal associations
In collaboration with Fiona Jevon (Yale University), I drew upon two large-scale datasets--the BAAD tree biomass and allometry database and the FungalRoot database of plant mycorrhizal associations--to investigate how tree biomass allocation varies in trees associated with arbuscular mycorrhizal vs. ectomycorrhizal fungi.
This work is in press at Ecology, and all code and data can be accessed via GitHub.
Soil carbon stabilization beneath trees of varying litter quality and mycorrhizal associations
What controls whether soil carbon is protected for long-term sequestration? Recent work suggests microbial communities may play a key role in the fate of soil organic matter as either particulate organic matter (POM) or mineral-associated organic matter (MAOM). I tested how both litter quality and mycorrhizal associations of trees influence the stabilization of carbon on mineral surfaces in soil from forests across New Hampshire and Vermont.
This work is currently in review, and data from this project can be accessed through the Environmental Data Initiative data portal.
Leaf litter decomposition along a forest mycorrhizal gradient
Most litter decomposition is carried out by free-living soil fungi, yet mycorrhizal fungi of dominant forest trees may affect the rate of litter decay through a variety of direct and indirect pathways. With this project, I tested how the mycorrhizal association of nearby trees influences the decomposition rate of four species of leaf litter in a forest.
Mycorrhizal fungi influence soil respiration in northern forests
Carbon efflux from forest soil is highly variable in space and time. While most ecosystem models use climate variables as the primary drivers of respiration rates, plant and microbial communities influence these patterns as well. With this project, I examined the role of fine roots and mycorrhizal fungi as drivers of soil respiration in a northern hardwood forest, and found that soil beneath AM-associated trees respires roughly 30% more carbon as CO2 compared to soil beneath ECM-associated trees.
Before my dissertation work, I had the opportunity to collaborate on several projects related to soil and sediment biogeochemistry: