Soil bacterial and fungal response to wildfires in the Canadian boreal forest across a burn severity gradient

Publication date: Available online 22 August 2019Source: Soil Biology and BiochemistryAuthor(s): Thea Whitman, Ellen Whitman, Jamie Woolet, Mike D. Flannigan, Dan K. Thompson, Marc-André ParisienAbstractGlobal fire regimes are changing, with increases in wildfire frequency and severity expected for many North American forests over the next 100 years. Fires can result in dramatic changes to carbon (C) stocks and can restructure plant and microbial communities, with long-lasting effects on ecosystem functions. We investigated wildfire effects on soil microbial communities (bacteria and fungi) in an extreme fire season in the northwestern Canadian boreal forest, using field surveys, remote sensing, and high-throughput amplicon sequencing in upland and wetland sites. We hypothesized that vegetation community and soil pH would be the most important determinants of microbial community composition, while the effect of fire might not be significant, and found that fire occurrence, along with vegetation community, moisture regime, pH, total carbon, and soil texture are all significant predictors of soil microbial community composition. Burned communities become increasingly dissimilar to unburned communities with increasingly severe burns, and the burn severity index (an index of the fractional area of consumed organic soils and exposed mineral soils) best predicted total bacterial community composition, while whether a site was burned or not was the best predictor for fungi. Globall...
Source: Soil Biology and Biochemistry - Category: Biology Source Type: research