Influences of host plant identity and disturbance on spatial structure and community composition of ectomycorrhizal fungi in a northern Mississippi uplands ecosystem

We sought to characterize how abiotic and biotic factors, including identities of tree hosts, influence ectomycorrhizal (ECM) fungal composition on tree roots in mixed upland forests of northern Mississippi, where sites have been subject to restoration treatments through burning, manual and natural (tornado) thinning. We identified both plant and fungal components of root tips and collected data on abiotic factors that potentially drive variation in ECM fungal community composition. We found that plant host identity and measured abiotic factors explained less than 8% of variation in ECM fungal community composition. ECM fungal community composition did not differ significantly between control and burned/thinned plots; however, it did differ substantially at the tornado-damaged plot, which also exhibited significant spatial structure. These results suggest that much variation in ECM communities is unexplained by commonly measured biotic and abiotic variables and natural disturbance may play a role in both community and spatial structure of ECM fungi.