title: Geological connectivity drives microbial community structure and connectivity in polar, terrestrial ecosystems.
abstract: Landscape heterogeneity impacts community assembly in animals and plants, but it is not clear if this ecological concept extends to microbes. To examine this question, we chose to investigate polar soil environments from the Antarctic and Arctic, where microbes often form the major component of biomass. We examined soil environments that ranged in connectivity from relatively well-connected slopes to patchy, fragmented landforms that comprised isolated frost boils. We found landscape connectedness to have a significant correlation with microbial community structure and connectivity, as measured by co-occurrence networks. Soils from within fragmented landforms appeared to exhibit less local environmental heterogeneity, harboured more similar communities, but fewer biological associations than connected landforms. This effect was observed at both poles, despite the geographical distances and ecological differences between them. We suggest that microbial communities inhabiting well-connected landscape elements respond consistently to regional-scale gradients in biotic and edaphic factors. Conversely, the repeated freeze thaw cycles that characterize fragmented landscapes create barriers within the landscape and act to homogenize the soil environment within individual frost boils and consequently the microbial communities. We propose that lower microbial connectivity in the fragmented landforms is a function of smaller patch size and continual disturbances following soil mixing.
authors: School of Biotechnology and Biomolecular Sciences, UNSW Australia, Randwick, NSW, 2052, Australia.
authors: Belinda C
authors: BC
authors: Ferrari
authors: CSIRO Agriculture Flagship, PO Box 1600, Canberra, ACT, 2601, Australia.
authors: Andrew
authors: A
authors: Bissett
authors: Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, 203 Channel Highway, Kingston, Tasmania, 7050, Australia.
authors: Ian
authors: I
authors: Snape
authors: School of Biotechnology and Biomolecular Sciences, UNSW Australia, Randwick, NSW, 2052, Australia.
authors: Josie
authors: J
authors: van Dorst
authors: Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, 203 Channel Highway, Kingston, Tasmania, 7050, Australia.
authors: Anne S
authors: AS
authors: Palmer
authors: School of Biotechnology and Biomolecular Sciences, UNSW Australia, Randwick, NSW, 2052, Australia.
authors: Mukan
authors: M
authors: Ji
authors: Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors: Steven D
authors: SD
authors: Siciliano
authors: Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, 203 Channel Highway, Kingston, Tasmania, 7050, Australia.
authors: Jonathon S
authors: JS
authors: Stark
authors: School of Biotechnology and Biomolecular Sciences, UNSW Australia, Randwick, NSW, 2052, Australia.|Australian Antarctic Division, Department of Sustainability, Environment, Water, Population and Communities, 203 Channel Highway, Kingston, Tasmania, 7050, Australia.|Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5A8, Canada.
authors: Tristrom
authors: T
authors: Winsley
authors: School of Biotechnology and Biomolecular Sciences, UNSW Australia, Randwick, NSW, 2052, Australia.
authors: Mark V
authors: MV
authors: Brown
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D001110:Arctic Regions; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D018533:Biomass; D017753:Ecosystem; D004777:Environment; D005658:Fungi / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D012987:Soil