What role do a communities climate history play in determining microbial response to perturbation?
This experiment examines the response of individual isolates and microbial communities from semi-arid and humid, tropical forest soils to reoccurring drought. This is a multi scale experiment, aimed at identifying and quantifying the traits and trade-offs of different microorganisms expressing a metabolic response to drought perturbation. This experiment is conducted at the scale of the individual microbe, and simple communities through a microfluidics-based platform, within intact soil cores within laboratory soil mesocosms, and by leveraging a throughfall exclusion experiment across a precipitation gradient in Panama. This study aims to further understanding of how microbial metabolism and community composition feeds back on the formation of soil organic matter and its in situ stability through sorption onto mineral surfaces.
This work employs a multiscale approach to better understand how microbial communities respond to stress.
This experiment examines the response of individual isolates and microbial communities from semi-arid and humid, tropical forest soils to reoccurring drought. This is a multi scale experiment, aimed at identifying and quantifying the traits and trade-offs of different microorganisms expressing a metabolic response to drought perturbation. This experiment is conducted at the scale of the individual microbe, and simple communities through a microfluidics-based platform, within intact soil cores within laboratory soil mesocosms, and by leveraging a throughfall exclusion experiment across a precipitation gradient in Panama. This study aims to further understanding of how microbial metabolism and community composition feeds back on the formation of soil organic matter and its in situ stability through sorption onto mineral surfaces.
This work employs a multiscale approach to better understand how microbial communities respond to stress.
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Field scale: We are working across a 1 meter precipitation transect in Panama, collaborating with Daniela Cusack (Colorado State University) on her PARCHED experiment. We work at four sites spanning this transect each of which houses a throughfall exclusion experiments. These experiments have maintained reduced soil moisture since late 2018. We sample soils across discrete depth intervals and use a combination of metagenomic sequencing and LC-MS/ NMR analysis to identify and quantify microbial traits and impacts of drought on organic matter composition.
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Mesocosm scale: The field experiment provides ecosystem-level information on microbial metabolic responses to drought. However, it also has the highest degrees of freedom, and an inability to replicate a more natural cycle of drought followed by precipitation and soil wet-up. To address this gap, we have translocated the field back to the lab, and established a soil mesocosm experiment using intact cores from one of our field sites. This experiment replicates the drought conditions of the field, alongside simultaneous experiments imposing drought and rewetting cycles.
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Population scale: While a laboratory mesocosm experiment provides an extra degree of control over external forcing conditions it is still of a scale which can preclude the elucidation of the critical mechanisms by which individual microbes and microbial communities respond to perturbation. Knowledge of the continuum of stress-related traits, in addition to cell-cell interactions, are critical in determining the structure and function of microbial communities. In order to provide further clarity to our mesocosm and field experiments we have stepped down to a population scale through the use of microfluidics and high-resolution, synchrotron-based experiments.
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Funding: This work is funded through a DOE Early Career Award.
