Document: JOH-3-58-1

Hydrologic response to reduced vegetative cover and soil removal in a sagebrush steppe community.

GIORDANENGO, J.H.* ¹, G.FRASIER ², M.J.TRLICA ¹ and E.F.REDENTE ¹

Colorado State University, Fort Collins, CO 80523-1478 ¹
Agricultural Research Service, Fort Collins, CO 80523 ²

Abstract:
Erosion is a serious problem throughout the world and has been linked to stream sedimentation, ecosystem degradation and loss of rangeland productivity. Measurements of soil surface hydrology provide a quantitative measure of soil erosion potential. Soil surface hydrology is directly and indirectly influenced by vegetative cover and soil loss. Thresholds of soil loss have been promulgated by the Natural Resource Conservation Service as a guide for ecosystem sustainability. However, knowledge of soil loss effects on rangeland productivity or ecosystem sustainability is lacking. Before thresholds can be determined, researchers must clarify the relationships between vegetative cover, soil loss and soil surface hydrology. The purpose of this research project was to determine the effects of vegetative cover removal and soil removal on soil surface hydrology (e.g., infiltration, surface runoff and sediment production) in a sagebrush steppe (Artemisia tridentata) ecosystem under simulated rainfall. Infiltration, sediment production, surface runoff, surface roughness and other factors were measured and evaluated for their response to three levels of vegetative cover removal (0, 30% and 60%) and soil removal (0, 11.2 and 22.4 tonnes ha-1). Preliminary results indicate that the maximum treatments resulted in a 13% reduction in the equilibrium runoff rate and a 30% reduction in the time to runoff.

Keywords: Soil erosion, vegetation reduction, hydrology, runoff, rangeland health

This abstract is being presented at: 4:30 PM in session:
Oral Session #49: Linkages Between Land and Streams.