Abstract
Forest soil microbiomes have crucial roles in carbon storage, biogeochemical cycling and rhizosphere processes. Wildfire season length, and the frequency and size of severe fires have increased owing to climate change. Fires affect ecosystem recovery and modify soil microbiomes and microbially mediated biogeochemical processes. To study wildfire-dependent changes in soil microbiomes, we characterized functional shifts in the soil microbiota (bacteria, fungi and viruses) across burn severity gradients (low, moderate and high severity) 1 yr post fire in coniferous forests in Colorado and Wyoming, USA. We found severity-dependent increases of Actinobacteria encoding genes for heat resistance, fast growth, and pyrogenic carbon utilization that might enhance post-fire survival. We report that increased burn severity led to the loss of ectomycorrhizal fungi and less tolerant microbial taxa. Viruses remained active in post-fire soils and probably influenced carbon cycling and biogeochemistry via turnover of biomass and ecosystem-relevant auxiliary metabolic genes. Our genome-resolved analyses link post-fire soil microbial taxonomy to functions and reveal the complexity of post-fire soil microbiome activity.
| Original language | English |
|---|---|
| Pages (from-to) | 1419-1430 |
| Number of pages | 12 |
| Journal | Nature Microbiology |
| Volume | 7 |
| Issue number | 9 |
| DOIs | |
| State | Published - Sep 2022 |
Funding
This work was supported through a USDA NIFA award (2021-67019-34608) to M.J.W. FTICR-MS analyses were performed under the Facilities Integrating Collaborations for User Science (FICUS) initiative and used resources at the Environmental Molecular Sciences Laboratory (proposal ID 49615), which is a DOE Office of Science User Facility. This facility is sponsored by the Office of Biological and Environmental Research and operated under contract number DE-AC05-76RL01830. Metagenomic and metatranscriptomic sequencing was performed at the University of Colorado Cancer Center\u2019s Genomics Shared Resource, which is supported by the Cancer Center Support Grant P30CA046934. This work utilized resources from the University of Colorado Boulder Research Computing Group, which is supported by the National Science Foundation (awards ACI-1532235 and ACI-1532236), the University of Colorado Boulder and Colorado State University. The work conducted by the US Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, is supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231. We thank F. Pulido-Chavez for help with processing the ITS amplicon sequencing data, and J. Emerson and S. Geonczy for discussions on viral analyses.