Global recovery patterns of soil microbes after fire

Soil microorganisms are a fundamental component of ecosystems and mediate biogeochemical cycles and ecosystem productivity. The frequency and extremity of fire weather is expected to increase under global warming; however, postfire soil microorganisms' patterns and trends remain unclear. By performing a global meta-analysis of 1019 paired observations of burned and unburned sites from 123 publications, we show that fungal biomass, microbial biomass carbon (C), soil respiration, autotrophic respiration, and C acquisition enzymes decrease in response to fire. The recovery times of microbial biomass and functional groups were shorter than those of soil C emissions and extracellular enzymes. Importantly, the postfire recovery of microbial biomass C and/or N as well as soil respiration and its components varied with mean annual temperature and precipitation, fire severity and type, and ecosystem type, with longer recovery times under high-severity fire/wildfire and in forests. Our study highlights the differential recovery patterns of microbial attributes after fire across global terrestrial ecosystems and reveals the importance of climate and the fire regime in regulating the postfire recovery of the soil microbial community and functioning.

Automated summary

Fire decreases fungal biomass, microbial biomass carbon, soil respiration, autotrophic respiration, and C acquisition enzymes. The recovery times of microbial biomass and functional groups are shorter than those of soil C emissions and extracellular enzymes. Climate and fire severity, type, and ecosystem type play important roles in regulating the postfire recovery of the soil microbial community and functioning.