Roy, BittyBailes, Graham2017-09-272017-09-27https://hdl.handle.net/1794/22783Prairies of the Pacific Northwest are threatened systems, with only ~2% of historic land remaining. The combined risk of global climate change and land use change make these systems a high conservation priority. However, little attention has been paid to the microbiota. Fungal endophytes are ubiquitous in plants and are important in ecosystem functioning and host dynamics. To understand fungal community assembly, we used high-throughput sequencing to investigate the composition of fungal foliar endophyte communities in two native, cool-season (C3) bunchgrasses along a natural latitudinal gradient. We quantified the importance of host, host traits, climate, edaphic factors, and spatial distance in microbial community composition. We found that spatial distance was the strongest predictors of endophyte community, while host traits (e.g., plant size, density) and abiotic environment were less important for community structure. These findings underline the importance of dispersal in shaping microbial communities. This thesis includes previously unpublished, co-authored material.en-USAll Rights Reserved.BunchgrassCommunityEndophytesFungiPrairieElectronic Thesis or Dissertation