Prokaryotic bacteria commonly found in BSC communities include cyanobacteria, chemoheterotrophic bacteria, and free-living diazotrophic (nitrogen fixing) bacteria. In this review of BSC organisms, we evaluate each organismal group independently, documenting how they contribute to the formation of BSCs, and how they reproduce and disperse. To be recognized as a contributor to the formation and maintenance of BSC communities, an organism must be involved in the consolidation and stabilization of soil particles and aggregates, resulting in the formation of an intact BSC community. Groups of organisms known to contribute to the formation BSC communities include cyano-, chemoheterotrophic, and diazotrophic bacteria, free-living, lichenized, and mycorrhizal fungi, terrestrial algae (including diatoms), and bryophytes ( Belnap et al., 2001 Weber et al., 2016). Many BSC organisms are photoautotrophic, fixing, and accumulating organic carbon ( Green and Proctor, 2016) while other organismal groups fix and distribute organic nitrogen. We also emphasize the importance of effective application of molecular and microenvironment sampling and assessment tools in order to provide cogent and essential answers that will allow scientists and land managers to better understand and manage the biodiversity and functional relationships of soil crust communities.īiological soil crusts (BSCs) consist of various combinations of living organisms that colonize, organize, and stabilize soil surfaces against the erosive forces of wind and water. With this publication, we provide literature-based insights as to how each organismal group contributes to the formation and maintenance of the structural and functional attributes of BSCs, how they reproduce, and how they are dispersed. The various BSC organismal groups demonstrate several common characteristics including-desiccation and extreme temperature tolerance, production of various soil binding chemistries, a near exclusive dependency on asexual reproduction, a pattern of aerial dispersal over impressive distances, and a universal vulnerability to a wide range of human-related perturbations. The list of organismal groups that make up BSC communities in various and unique combinations include-free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms-including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. 7Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, United Statesīiological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces.6Department of Microbiology and Plant Pathology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, United States.5Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, United States.4School of Life Sciences, University of Nevada, Las Vegas, NV, United States.3Monte Lafayette Bean Life Science Museum, Brigham Young University, Provo, UT, United States.2Department of Biology, Brigham Young University, Provo, UT, United States.Forest Service, Rocky Mountain Research Station, Provo, UT, United States Lewis 5, Nuttapon Pombubpa 6, Tania Kurbessoian 6, Jason E.

Dispersio patters of of orgaisms