Infiltrometer studies in rangeland plant communities of the Northern Territory.

Abstract

Infiltrometer studies were conducted within several plant communities near Alice Springs, Northern Territory. Plant commu- nities studied included mulga-perennial, mulga-shortgrass, savanna woodland, gilgai, flood-plain grassland, and scalded areas (no vegetation). Attempts were made to quantify the impact of surface crusting, antecedent soil moisture conditions, and time of year on infiltration rates and potential sediment yields. Results indicate that the infiltration process within certain plant communities is often complex, and hydrologic differences which occur both within and among the plant communities should be acknowledged. Sediment yields from a floodplain-grassland unit and a scald situation were about 2 and 5 times greater, respectively, than those from various mulga communities, woodland, or gilgai circumstances. With one exception, antecedent soil moisture had little influence on sediment yields. Removal of surface soil crusts significantly increased sediment yields, regardless of antecedent soil moisture conditions. The relationship between soil movement and loss and ecosystem stability needs to be established for most rangeland environments, but little has been done to satisfy this need.