Ecological Determinants of Species Composition of Biological Soil Crusts on a Landscape Scale

Structure and composition of biological soil crusts varies with substrate, climate, and successional processes (see Chaps. 1–11), and specific factors controlling the distribution and abundance of crustal organisms may vary across different scales (see Chap. 16). On a landscape scale (i.e., from meters to kilometers), variation and limitation of soil crusts are mainly related to precipitation, soil chemistry and texture, topography, cover of phanerogamic vegetation, and disturbance. However, because of the problems with taxonomic identifications (see Chap. 1), most relevant studies omit analyses of floristic variation or treat only with a fraction of the flora present.