Soil Microbial Community Responses Following Severe Wildfires in the Linville Gorge, Burke County, NC.

The belowground community response to wildfire is often linked to the chemical, physical, and biological properties of soils. Fundamental processes such as soil respiration are strongly influenced by changes in soil biogeochemical parameters caused by wildfire. However, due to the complex interactions between soil properties and processes, the microbial response is often unpredictable. This study investigates the composition of soil bacterial communities in burned and unburned soils in an attempt to understand how these diverse communities respond to wildfire.This study had three main objectives: (1) to measure basic belowground biogeochemical parameters at paired burned and unburned sites in three burn areas, (2) to describe and compare soil microbial community structure between burned and unburned soils, and (3) to analyze the relationship between functionally important microbial groups and soil biogeochemistry. Soil respiration, soil C, and soil N were all influenced by wildfires. Fires decreased microbial diversity (inverse Simpson diversity, P<0.001) and reduced the abundance of nitrifying bacteria in the most recently burned soils. The results of this study indicate that wildfire resulted in changes to soil chemical parameters and caused a significant shift in bacterial community composition and reductions in overall diversity.