title: Consistently inconsistent drivers of microbial diversity and abundance at macroecological scales.
abstract: Macroecology seeks to understand broad-scale patterns in the diversity and abundance of organisms, but macroecologists typically study aboveground macroorganisms. Belowground organisms regulate numerous ecosystem functions, yet we lack understanding of what drives their diversity. Here, we examine the controls on belowground diversity along latitudinal and elevational gradients. We performed a global meta-analysis of 325 soil communities across 20 studies conducted along temperature and soil pH gradients. Belowground taxa, whether bacterial or fungal, observed along a given gradient of temperature or soil pH were equally likely to show a linear increase, linear decrease, humped pattern, trough-shaped pattern, or no pattern in diversity along the gradient. Land-use intensity weakly affected the diversity-temperature relationship, but no other factor did so. Our study highlights disparities among diversity patterns of soil microbial communities. Belowground diversity may be controlled by the associated climatic and historical contexts of particular gradients, by factors not typically measured in community-level studies, or by processes operating at scales that do not match the temporal and spatial scales under study. Because these organisms are responsible for a suite of key processes, understanding the drivers of their distribution and diversity is fundamental to understanding the functioning of ecosystems.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, Tennessee, 37996, USA.|The Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado, 81224, USA.
authors.forename: John Nicholas
authors.initials: JN
authors.lastname: Hendershot
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, Tennessee, 37996, USA.|The Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado, 81224, USA.
authors.forename: Quentin D
authors.initials: QD
authors.lastname: Read
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, Tennessee, 37996, USA.|The Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado, 81224, USA.
authors.forename: Jeremiah A
authors.initials: JA
authors.lastname: Henning
authors.affiliation: The Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado, 81224, USA.|Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, 05405, USA.|Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, Copenhagen, 2100, Denmark.
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Sanders
authors.affiliation: The Rocky Mountain Biological Laboratory, P.O. Box 519, Crested Butte, Colorado, 81224, USA.|Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, Vermont, 05405, USA.|Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, Copenhagen, 2100, Denmark.
authors.forename: Aimée T
authors.initials: AT
authors.lastname: Classen
mesh_terms: D001419:Bacteria / Q000145:classification*; D044822:Biodiversity; D017753:Ecosystem; D005658:Fungi / Q000145:classification*; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil
keywords: belowground communities; gradients; latitudinal diversity gradient; macroecology; meta-analysis; microbial diversity; soil