Tue, Aug 16, 2022: 10:45 AM-11:00 AM
513A
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 “biocrustâ€, 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.
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 “biocrustâ€, 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.