COS 61-4 - What is a biocrust? A refined, contemporary definition for a broadening research community.

Tuesday, August 16, 2022

10:45 AM – 11:00 AM EDT

Location: 513A

Coauthor(s)

BW

Bettina Weber

University of Graz, Austria
JB

Jayne Belnap

US Geological Survey, United States
BB

Burhhard Budel

University of Kaiserslautern, Germany
AA

Anita J. Antoninka, PhD

Assistant Professor, School of Forestry, Northern Arizona University
School of Forestry, Northern Arizona University, United States
NB

Nichole Barger

Professor
University of Colorado Boulder, United States
BC

Bala Chaudhary

Dartmouth College
Chicago, New Hampshire, United States
AD

Anthony Darrouzet-Nardi

University of Texas at El Paso, United States
DE

David Eldridge

University of New South Wales, United States
AF

Akasha M. Faist

Assistant Professor of Rangeland Ecology
New Mexico State University
Las Cruces, NM, United States
SF

Scott Ferrenberg, PhD

Assistant Professor
New Mexico State University, United States
CH

Caroline Havrilla

Colorado State University, United States
EH

Elisabeth Huber-Sanwald

Associate Professor
Instituto Potosino de Investigación Científica y Tecnológica A.C.
San Luis Potosí, San Luis Potosi, Mexico
OM

Oumarou Malam Issa

SU/IRD/CNRS/INRAE/UPEC, France
FM

Fernando Maestre

Universidad de Alicante, Spain
SR

Sasha C. Reed

Research Ecologist
U.S. Geological Survey
Moab, UT, United States
ER

Emilio Rodriguez-Caballero

Consejo Superior de Investigaciones Científicas, Spain
CT

Colin Tucker, PhD

Research Ecologist
USDA Forest Service, Northern Research Station
Madison, Michigan, United States
KY

Kristina E. Young

Utah State University, United States
YZ

Yuanming Zhang

Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China (People's Republic)
YZ

Yunge Zhao

Institute of Soil and Water Conservation, Northwest A & F University, China (People's Republic)
XZ

Xiaobing Zhou

Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, China (People's Republic)

Presenting Author(s)

MB

Matthew A. Bowker

Associate Professor
Northern Arizona University
Flagstaff, Arizona, United States

Background/Question/Methods

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 widening 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. We synthesized the literature with the views of new and experienced biocrust researchers to identify the key elements defining a biocrust, and provide a refined and fully elaborated definition of biocrusts.

Results/Conclusions

We demonstrate that biocrusts are defined by four distinct elements: the physical structure, functional characteristics, habitat, and taxonomical composition. We identified 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 found that a wide variety of different types of soil surface communities fall under our definition of biocrusts, in the process of highlighting their global distribution. Finally, we suggest the universal use of the Belnap et al. (2003) 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 millimeters 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 wide-spread distribution, we hope to stimulate interest in biocrust research and inform various stakeholders of their overall importance to ecosystem and Earth system functioning.