Arbuscular mycorrhizal fungal communities show low resistance and high resilience to wildfire disturbance

Wildfires are important disturbances that help to shape the structure and function of forest ecosystems, and arbuscular mycorrhizal fungi (AMF) are key players in the post-fire recovery of soils and understory vegetation. We aimed to investigate the response of AMF communities to wildfire over different timescales. Primer set AMV4.5NF/AMDGR was used to amplify soil 18S rRNA gene fragments for the 454 GS-FLX pyrosequencing platform to examine belowground AMF communities 1 and 11 years following low- and high-intensity wildfires in the Greater Khingan Mountains of China. The majority of AMF sequences detected were annotated as Glomeraceae, Claroideoglomeraceae, Diversisporaceae and Acaulosporaceae. Both AMF community composition and alpha-diversity were correlated with herbaceous and shrubby biomass, available phosphorus (AP) and NH4 (+), which were in turn altered by wildfire. AMF community composition, alpha-diversity, and phylogenetic structure were significantly altered 1-year-post-fire. However, AMF communities were indistinguishable from unburned forest soils 11-year-post-fire. Our results indicated that AMF communities are resilient to wildfire on decadal timescales. This resilience appears to depend on the post-fire regrowth of understory vegetation and the subsequent recovery of soil chemical properties.