title: Namib Desert edaphic bacterial, fungal and archaeal communities assemble through deterministic processes but are influenced by different abiotic parameters.
abstract: The central Namib Desert is hyperarid, where limited plant growth ensures that biogeochemical processes are largely driven by microbial populations. Recent research has shown that niche partitioning is critically involved in the assembly of Namib Desert edaphic communities. However, these studies have mainly focussed on the Domain Bacteria. Using microbial community fingerprinting, we compared the assembly of the bacterial, fungal and archaeal populations of microbial communities across nine soil niches from four Namib Desert soil habitats (riverbed, dune, gravel plain and salt pan). Permutational multivariate analysis of variance indicated that the nine soil niches presented significantly different physicochemistries (R2= 0.8306, P ≤ 0.0001) and that bacterial, fungal and archaeal populations were soil niche specific (R2≥ 0.64, P ≤ 0.001). However, the abiotic drivers of community structure were Domain-specific (P < 0.05), with P, clay and sand fraction, and NH4influencing bacterial, fungal and archaeal communities, respectively. Soil physicochemistry and soil niche explained over 50% of the variation in community structure, and communities displayed strong non-random patterns of co-occurrence. Taken together, these results demonstrate that in central Namib Desert soil microbial communities, assembly is principally driven by deterministic processes.
authors.affiliation: Centre for Microbial Ecology and Genomics, Genomics Research Institute, Natural Sciences 2, University of Pretoria, Room 3-20, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
authors.forename: Riegardt M
authors.initials: RM
authors.lastname: Johnson
authors.affiliation: Centre for Microbial Ecology and Genomics, Genomics Research Institute, Natural Sciences 2, University of Pretoria, Room 3-20, Private Bag X20, Hatfield, Pretoria, 0028, South Africa. jean-baptiste.ramond@up.ac.za.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Ramond
authors.affiliation: Centre for Microbial Ecology and Genomics, Genomics Research Institute, Natural Sciences 2, University of Pretoria, Room 3-20, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
authors.forename: Eoin
authors.initials: E
authors.lastname: Gunnigle
authors.affiliation: Gobabeb Research and Training Centre, Walvis Bay, Namibia.|School of Animal, Plant and Environmental Sciences (AP&ES), University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Mary
authors.initials: M
authors.lastname: Seely
authors.affiliation: Centre for Microbial Ecology and Genomics, Genomics Research Institute, Natural Sciences 2, University of Pretoria, Room 3-20, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
authors.forename: Don A
authors.initials: DA
authors.lastname: Cowan
mesh_terms: D001105:Archaea / Q000254:growth & development*; D001419:Bacteria / Q000254:growth & development*; D003889:Desert Climate; D005658:Fungi / Q000254:growth & development*; D059013:Microbial Consortia / Q000502:physiology*; D009276:Namibia; D012988:Soil Microbiology
keywords: Desert ecology; Deterministic drivers; Microbial community assembly; Soil environments