The effect of algal-mold crusts on the hydrologic processes of infiltration, runoff, and soil erosion under simulated conditions.

Abstract

Studies were conducted to evaluate the effects of blue-green algae and molds growing on soil surfaces on infiltration, runoff, and suspended and settleable sediment production. Two contrasting soil types were used: a fine-textured clay of the Puna series and a coarse textured river alluvium of the Anthony series. A modified type F rainfall simulator was employed to apply simulated high and low intensity rainfall to soil surfaces encrusted with or denuded of micro-vegetation. The micro-vegetation was grown on the plot surfaces under artificial conditions. Results of the study indicate that soil type and rainfall intensity influences on infiltration and runoff are difficult to separate from micro-vegetation effects. However, significantly greater amounts of suspended sediment were carried in the runoff water from the surfaces of the denuded plots than from those encrusted with blue-green algae and molds.