PRJNA450808
Landscape fire and grazing management history affects soil microbial biogeography
Microbes matter to environmental health - both ecosystem and animal host environments. Animals are an integral part of ecosystems, especially at a landscape scale. Human animals manage ecosystems for agriculture and conservation, and in both agricultural and "wild" ecosystems, non-human animals are often the most charismatic fauna. In addition to microbes supporting soil, animal and ecosystem health, animals may affect microbes in ecosystems. Animals move cells around landscapes, and themselves act as selective filters within the landscape. Non-human and human animals also influence ecosystem attributes like soil pH, soil organic matter, soil nitrogen availability, and soil water content, which in turn can promote the growth of certain types of microbes. Biogeography and metacommunity concepts offer a framework through which to consider the relative influence of microbial movement/dispersal and environmental filtering on soil microbial diversity and microbial community composition. An experimental context in which animal presence and ecosystem attributes are manipulated in factorial is also particularly powerful. Patterns in microbial biogeography are often analogous to patterns in plant biogeography, so there is reason to predict animal-mediated dispersal and environmental filtering may affect soil microbial diversity and community composition in our experimental landscape, similar to plant patterns of diversity. We measured soil microbial community composition in a log-space design across watersheds with a long-term history of annual fire (or infrequent fire) and bison grazing (or no grazing). These watershed-scale treatments affected soil microbial diversity in a way that supports the hypothesis that fire and grazing affect microbial dispersal patterns and thus soil microbial biodiversity.