Soil microbial community composition, diversity, and richness can significantly affect the diversity and productivity of plant communities. In turn, responses of host plant communities to land use disturbance may change costs and benefits of hosting AMF and thus the structure of their endosymbiont AMF communities. Here we examine how variation in land use/disturbance history (remnant vs. disturbed) and soil substrate (acidic vs. calcareous) affect AMF community composition in glades of the Ozarks Plateau and nearby tallgrass prairies of the Osage Plains in southern Missouri, USA. To determine if disturbance history alters AMF communities differently in glades and prairies, we surveyed AMF communities on roots of two generalist plant species (Ruellia humilis and Schizachyrium scoparium) as well as on randomly selected roots collected at large in the rhizosphere.
Results/Conclusions
Changes in AMF community composition with habitat type, land use history, and soil substrate were similar for endosymbionts on roots of R. humilis and S. scoparium and in the rhizosphere at large. AMF communities varied significantly between glades and prairies. Within glades, AMF community composition varied across soil substrate but not land use history. In prairies, AMF communities in remnant sites differed from those of degraded sites, regardless of soil substrate. Variation in AMF community structure between degraded and remnant prairie occurred at multiple spatial scales: differing between spatially separated degraded and remnant prairie fragments as well as between degraded and remnant habitats of the same prairie fragment. Though most AMF taxa were present in all sites, shifts in dominant taxa were responsible for the differences seen across land use history in prairies and soil substrates in glades. Differences in how glade and prairie AMF communities respond to land use history are unlikely to reflect host limitation since our sampling protocol targeted the same suite of common plant species in both habitats. Instead, results suggest that disturbance regimes associated with conversion to industrial agriculture in prairies are far more disruptive to AMF than fire suppression/woody encroachment in glades.