Microorganisms of Biological Crusts on Soil Surfaces

Abstract

Our knowledge of the biodiversity of soil crust biota from different geographical regions is rather dissimilar. This, on the one hand, is based on different methods applied by most floristic studies (e.g., determination is only rarely based on cultured material in the case of cyanobacteria, algae and fungi). On the other hand, the species concept, especially of cyanobacteria, is currently in a state of flux. For future research, the application of molecular tools should be of great help (e.g., fluorescence in situ hybridization (FISH), DNA chips for the most common taxa). More attention must also be drawn to the heterotrophic part of soil crusts in order to fully understand turnover rates. In the ecological context, it would be important to focus on their role as primary producers, as C and N sinks or as soil stabilizers against erosion. Moreover, their influence on higher plant diversity and succession needs more investigation before we really understand the role of biological soil crusts in the ecosystem context.