Wildfire-dependent changes in soil microbiome diversity and function

Area of Science:

• Forest ecology
• Soil microbiology
• Climate change impacts

Background:

• Forest soil microbiomes are vital for carbon storage and nutrient cycling.
• Climate change is increasing wildfire frequency and severity, impacting ecosystems.
• Wildfires significantly alter soil microbial communities and their functions.

Purpose of the Study:

• To investigate wildfire-induced functional shifts in soil microbiota (bacteria, fungi, viruses).
• To analyze these shifts across different burn severity gradients one year post-fire.
• To understand the implications for post-fire forest ecosystem recovery.

Main Methods:

• Characterized soil microbial communities (bacteria, fungi, viruses) across low, moderate, and high burn severity gradients.
• Analyzed functional gene profiles related to microbial survival and biogeochemical processes.
• Utilized genome-resolved analyses to link microbial taxonomy to function.

Main Results:

• Observed severity-dependent increases in Actinobacteria with genes for heat resistance and pyrogenic carbon utilization.
• Documented loss of ectomycorrhizal fungi and sensitive microbial taxa with increasing burn severity.
• Confirmed continued viral activity influencing carbon cycling and auxiliary metabolic genes.

Conclusions:

• Post-fire soil microbial communities exhibit functional shifts related to burn severity.
• Actinobacteria may play a key role in post-fire forest resilience.
• Viruses contribute to post-fire biogeochemical processes, highlighting microbiome complexity.