TY - JOUR
T1 - What is a biocrust? A refined, contemporary definition for a broadening research community
AU - Weber, Bettina
AU - Belnap, Jayne
AU - Büdel, Burkhard
AU - Antoninka, Anita J.
AU - Barger, Nichole N.
AU - Chaudhary, V. Bala
AU - Darrouzet-Nardi, Anthony
AU - Eldridge, David J.
AU - Faist, Akasha M.
AU - Ferrenberg, Scott
AU - Havrilla, Caroline A.
AU - Huber-Sannwald, Elisabeth
AU - Malam Issa, Oumarou
AU - Maestre, Fernando T.
AU - Reed, Sasha C.
AU - Rodriguez-Caballero, Emilio
AU - Tucker, Colin
AU - Young, Kristina E.
AU - Zhang, Yuanming
AU - Zhao, Yunge
AU - Zhou, Xiaobing
AU - Bowker, Matthew A.
N1 - Funding Information:
We would like to express our sincere gratitude to Otto L. Lange, who openly shared his ideas on biocrusts and worked with us on an earlier version of this review. This work was conducted as part of the “Completing the dryland puzzle: creating a predictive framework for biological soil crust function and response to climate change” Working Group supported by the John Wesley Powell Center for Analysis and Synthesis, funded by the U.S. Geological Survey. V.B.C. is funded by the National Science Foundation (DEB‐1844531). F.T.M. acknowledges support from the European Research Council (ERC Grant Agreement 647038 [BIODESERT]) and Generalitat Valenciana (CIDEGENT/2018/041). K.E.Y. and A.D.‐N. were supported by the National Science Foundation (#1557162 & #1557135). E.R.‐C. was supported by the Ramon y Cajal fellowship (RYC2020‐030762‐I) and the REBIOARID Project (2018‐101921‐B‐I00) founded by FEDER/Ministerio de Ciencia e Inovacion‐Agencia estatal de investigacion, and the BIOCOST project (Conservación debiocostras como estrategia de adaptación al cambio climático: alineando avances científicos con la gestión y sociedad) supported by the Biodiversity Foundation of the Ministry for the Ecological Transition and the Demographic Challenge. S.C.R. was supported by USGS Ecosystems Mission Area. E.H.‐S. acknowledges financial support from CONACYT grant SEP‐CB‐2015‐01‐251388. We are grateful to the Fort Collins, Colorado, Whole Foods salad bar for providing considerable fodder, both figurative and literal, that supported many lengthy discussions leading to this review. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Publisher Copyright:
© 2022 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.
PY - 2022/10
Y1 - 2022/10
N2 - Studies of biological soil crusts (biocrusts) have proliferated over the last few decades. The biocrust literature has broadened, with more studies assessing and describing the function of a variety of biocrust communities in a broad range of biomes and habitats and across a large spectrum of disciplines, and also by the incorporation of biocrusts into global perspectives and biogeochemical models. As the number of biocrust researchers increases, along with the scope of soil communities defined as ‘biocrust’, it is worth asking whether we all share a clear, universal, and fully articulated definition of what constitutes a biocrust. In this review, we synthesize the literature with the views of new and experienced biocrust researchers, to provide a refined and fully elaborated definition of biocrusts. In doing so, we illustrate the ecological relevance and ecosystem services provided by them. We demonstrate that biocrusts are defined by four distinct elements: physical structure, functional characteristics, habitat, and taxonomic composition. We describe outgroups, which have some, but not all, of the characteristics necessary to be fully consistent with our definition and thus would not be considered biocrusts. We also summarize the wide variety of different types of communities that fall under our definition of biocrusts, in the process of highlighting their global distribution. Finally, we suggest the universal use of the Belnap, Büdel & Lange definition, with minor modifications: Biological soil crusts (biocrusts) result from an intimate association between soil particles and differing proportions of photoautotrophic (e.g. cyanobacteria, algae, lichens, bryophytes) and heterotrophic (e.g. bacteria, fungi, archaea) organisms, which live within, or immediately on top of, the uppermost millimetres of soil. Soil particles are aggregated through the presence and activity of these often extremotolerant biota that desiccate regularly, and the resultant living crust covers the surface of the ground as a coherent layer. With this detailed definition of biocrusts, illustrating their ecological functions and widespread distribution, we hope to stimulate interest in biocrust research and inform various stakeholders (e.g. land managers, land users) on their overall importance to ecosystem and Earth system functioning.
AB - Studies of biological soil crusts (biocrusts) have proliferated over the last few decades. The biocrust literature has broadened, with more studies assessing and describing the function of a variety of biocrust communities in a broad range of biomes and habitats and across a large spectrum of disciplines, and also by the incorporation of biocrusts into global perspectives and biogeochemical models. As the number of biocrust researchers increases, along with the scope of soil communities defined as ‘biocrust’, it is worth asking whether we all share a clear, universal, and fully articulated definition of what constitutes a biocrust. In this review, we synthesize the literature with the views of new and experienced biocrust researchers, to provide a refined and fully elaborated definition of biocrusts. In doing so, we illustrate the ecological relevance and ecosystem services provided by them. We demonstrate that biocrusts are defined by four distinct elements: physical structure, functional characteristics, habitat, and taxonomic composition. We describe outgroups, which have some, but not all, of the characteristics necessary to be fully consistent with our definition and thus would not be considered biocrusts. We also summarize the wide variety of different types of communities that fall under our definition of biocrusts, in the process of highlighting their global distribution. Finally, we suggest the universal use of the Belnap, Büdel & Lange definition, with minor modifications: Biological soil crusts (biocrusts) result from an intimate association between soil particles and differing proportions of photoautotrophic (e.g. cyanobacteria, algae, lichens, bryophytes) and heterotrophic (e.g. bacteria, fungi, archaea) organisms, which live within, or immediately on top of, the uppermost millimetres of soil. Soil particles are aggregated through the presence and activity of these often extremotolerant biota that desiccate regularly, and the resultant living crust covers the surface of the ground as a coherent layer. With this detailed definition of biocrusts, illustrating their ecological functions and widespread distribution, we hope to stimulate interest in biocrust research and inform various stakeholders (e.g. land managers, land users) on their overall importance to ecosystem and Earth system functioning.
KW - biocrust
KW - biological soil crust
KW - climate.
KW - definition
KW - function
KW - habitat
KW - physical structure
KW - taxonomy
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U2 - 10.1111/brv.12862
DO - 10.1111/brv.12862
M3 - Article
AN - SCOPUS:85130263616
SN - 0006-3231
VL - 97
SP - 1768
EP - 1785
JO - Biological Reviews of the Cambridge Philosophical Society
JF - Biological Reviews of the Cambridge Philosophical Society
IS - 5
ER -