Biogeochemical consequences of microbial trait tradeoffs under drought, wildfire, and nitrogen addition
EMSL Project ID
51865
Abstract
Environmental perturbations such as drought, nitrogen deposition, and wildfire are becoming increasingly frequent and severe in the western United States. These disturbances are expected to alter soil microbiomes, but the consequences for carbon and nutrient cycling remain unclear. To address this uncertainty, we will test a new trait-based theory of microbial metabolism that connects disturbance response with biogeochemical functioning through microbial physiological traits at genome through community scales. A key assumption of our theory is that finite resources result in tradeoffs among traits underlying the three life history strategies: growth Yield, resource Acquisition, and Stress tolerance (YAS). We propose three complementary experiments to test the YAS framework across the plant litter-soil interface with interacting drought, wildfire, and nitrogen disturbances. The first experiment, on plant litter substrate, will apply genomic analyses and physiological assays to quantify evolutionary adaptation to drought by fungi with different YAS life history strategies. The second experiment will apply a suite of ‘omics approaches in a microbial community transplant experiment on plant litter to assess trait tradeoffs in microbiomes exposed to drought and wildfire. The third experiment will apply quantitative stable isotope probing to measure the growth yield traits of microbiomes recovering from wildfire in surface soils exposed to long-term drought and nitrogen disturbance. Complementary genomic, physiological, and soil physiochemical analyses before and after fire will help assess tradeoffs between growth, resource acquisition, and stress tolerance traits. The data generated from these experiments will be used to improve DEMENT, our trait-based microbiome model, and better predict the biogeochemical consequences of microbial metabolic tradeoffs under different disturbances. To analyze microbial life history traits, we request resources provided by EMSL to conduct metabolomic profiling and analyses on leaf litter and surface soil samples from our field experiments using liquid chromatography mass spectrometry (LC-MS). We also request proteomics, proton nuclear magnetic resonance (1H-NMR), and X-Ray Computed Tomography (XCT) imaging capabilities to characterize the soil environments that influence and are altered by microbial life history traits. These analyses will provide the missing link in our understanding of how genomic data relate to microbial metabolism and how trait-based microbial strategies influence biogeochemical functioning. Furthermore, these data will be used to validate DEMENT’s trait-based and spatially-explicit model predictions of microbiome composition and biogeochemical rates in the context of disturbance.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2021-10-01
End Date
2023-11-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)