Not much of the research in the Columbia Basin has focused on crust influences on the soil hydrologic or soil stability processes described below. Soil Stability Cyanobacteria and green algae have filamentous growth forms that bind soil particles. These filaments exude sticky polysaccharide sheaths around their cells that aid in soil aggregation by cementing particles together. The aggregate stability from these binding actions, and the increased surface topography of some crusts, improves resistance to wind and water erosion. Nutrient Contributions Cyanobacteria can increase available nitrogen as well as other nutrients in the soil.
Crusts can be the dominant source of fixed nitrogen in some semiarid ecosystems.
The nitrogen appears to be available to higher plants. The water holding capacity of crusts has been proposed to benefit surrounding vegetation by slowing evaporation. It has also been proposed that this ability to hold water may be so strong as to prevent vegetation from accessing it, thereby decreasing available water. So far, a conclusion has not been reached on this issue. Results are likely to be site specific.