title: Soil microbial communities and elk foraging intensity: implications for soil biogeochemical cycling in the sagebrush steppe.
abstract: Foraging intensity of large herbivores may exert an indirect top-down ecological force on soil microbial communities via changes in plant litter inputs. We investigated the responses of the soil microbial community to elk (Cervus elaphus) winter range occupancy across a long-term foraging exclusion experiment in the sagebrush steppe of the North American Rocky Mountains, combining phylogenetic analysis of fungi and bacteria with shotgun metagenomics and extracellular enzyme assays. Winter foraging intensity was associated with reduced bacterial richness and increasingly distinct bacterial communities. Although fungal communities did not respond linearly to foraging intensity, a greater β-diversity response to winter foraging exclusion was observed. Furthermore, winter foraging exclusion increased soil cellulolytic and hemicellulolytic enzyme potential and higher foraging intensity reduced chitinolytic gene abundance. Thus, future changes in winter range occupancy may shape biogeochemical processes via shifts in microbial communities and subsequent changes to their physiological capacities to cycle soil C and N.
authors.affiliation: Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, USA.
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Cline
authors.affiliation: School of Natural Resources & Environment, University of Michigan, Ann Arbor, MI, USA.|Department of Ecology & Evolution, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Zak
authors.affiliation: School of Natural Resources & Environment, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Rima A
authors.initials: RA
authors.lastname: Upchurch
authors.affiliation: Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA.
authors.forename: Zachary B
authors.initials: ZB
authors.lastname: Freedman
authors.affiliation: Department of Conservation Biology, University of Minnesota, St. Paul, MN, USA.
authors.forename: Anna R
authors.initials: AR
authors.lastname: Peschel
mesh_terms: D000818:Animals; D019306:Artemisia / Q000254:growth & development; D001419:Bacteria / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D057486:Carbon Cycle; D003670:Deer / Q000502:physiology*; D005658:Fungi / Q000235:genetics / Q000502:physiology*; D065948:Grassland; D060434:Herbivory; D058458:Nitrogen Cycle; D012621:Seasons; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D014959:Wyoming
chemical_list: D012987:Soil
keywords: Bacteria; community assembly; decomposition; extracellular enzyme; foraging; functional gene; fungi; herbivore; metagenome