Disturbance reduces the differentiation of mycorrhizal fungal communities in grasslands along a precipitation gradient.

Geoffrey L House,James D Bever

doi:10.1002/eap.1681

Geoffrey L House, James D Bever

Open Access

https://doi.org/10.1002/eap.1681

Copy DOI

Journal: Ecological Applications	Publication Date: Mar 5, 2018
Citations: 46	License type: CC BY 4.0

Affiliation: Indiana University, University of Kansas

Abstract

Given that mycorrhizal fungi play key roles in shaping plant communities, greater attention should be focused on factors that determine the composition of mycorrhizal fungal communities and their sensitivity to anthropogenic disturbance. We investigate changes in arbuscular mycorrhizal (AM) fungal community composition across a precipitation gradient in North American grasslands as well as changes occurring with varying degrees of site disturbance that have resulted in invasive plant establishment. We find strong differentiation of AM fungal communities in undisturbed remnant grasslands across the precipitation gradient, whereas communities in disturbed grasslands were more homogeneous. These changes in community differentiation with disturbance are consistent with more stringent environmental filtering of AM fungal communities in undisturbed sites that may also be promoted by more rigid functional constraints imposed on AM fungi by the native plant communities in these areas. The AM fungal communities in eastern grasslands were particularly sensitive to anthropogenic disturbance, with disturbed sites having low numbers of AM fungal operational taxonomic units (OTUs) commonly found in undisturbed sites, and also the proliferation of AM fungal OTUs in disturbed sites. This proliferation of AM fungi in eastern disturbed sites coincided with increased soil phosphorus availability and is consistent with evidence suggesting the fungi represented by these OTUs would provide reduced benefits to native plants. The differentiation of AM fungal communities along the precipitation gradient in undisturbed grasslands but not in disturbed sites is consistent with AM fungi aiding plant adaptation to climate, and suggests they may be especially important targets for conservation and restoration in order to help maintain or re-establish diverse grassland plant communities.

Highlights

The conservation and restoration of ecosystems impacted by human activities remains a pressing need
There was not a significant skew in the number of abundant operational taxonomic units (OTUs) when comparing remnant and disturbed sites for all samples (Fig. 3a), there was significant phylogenetic clustering among the OTUs that were more abundant in remnant sites (Table 2)
When considering only samples from remnant sites, there was no difference in the number or the phylogenetic clustering of OTUs that were abundant on either side of the precipitation gradient (Fig. 3b, Table 2)

Summary

Introduction

The conservation and restoration of ecosystems impacted by human activities remains a pressing need. Conservation and restoration practices should be informed by an understanding of the forces that structure and stabilize the ecosystems of interest. Consistent with this, soil microbial amendments have been shown to improve the restoration of native plant diversity (Middleton and Bever 2012, Wubs et al 2016), and soil microbes can mediate plant adaptation to the environment (Johnson et al 2010, Rua et al 2016).

Methods

Results

Discussion

Conclusion