- Biological Soil Crusts in Post-Mining Areas

The term Biological Soil Crust (BSC) (formerly also called biotic or cryptogamic crust) is generally used for the associations of cyanobacteria, algae, lichens, and bryophytes (in different proportions) growing on the soil surface, and binding it together. Biological soil crusts do not only consist of photosynthetic organisms, but typically also contain signifi cant fungal, bacterial, and invertebrate populations. BSCs are common in ecosystems with a high light input at the soil surface. They occur in almost all arid and semiarid regions worldwide, from polar to hot deserts, as well as in local arid microenvironments (edaphically dry areas) of the temperate zones. In arid and semi-arid landscapes, these crusts are dominated by cyanobacteria, lichens, or bryophytes. Crusts dominated by green algae and/or other eukaryotic algal groups appear in the soils of temperate regions, or in slightly acidic desert soils (Büdel 2001b). BSCs are critical structural and functional components in many ecosystems in arid and semiarid regions, where they may even represent the climax community. In temperate arid microhabitats they usually form the initial or early stages of plant succession; and may either speed up or slow down the succession of higher plants.