Biological Soil Crusts in Three Sagebrush Communities Recovering from a Century of Livestock Trampling

Abstract

Biological soil crusts and their recovery from long-term livestock impacts were studied in three sagebrush communities in east-central Idaho. In 1996, biological crust and vascular plant cover were measured outside and inside of livestock exclosures in Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), mountain big sagebrush (Artemisia tridentata ssp. vaseyana), and low sagebrush (Artemisia arbuscula) communities. The Wyoming big sagebrush exclosure had the greatest cover of biological crust relative to the vascular plant canopy. Biological crust cover was double inside the Wyoming and mountain big sagebrush exclosures compared to the areas outside, indicating substantial recovery since release from livestock use 8 and 11 years previous, respectively. The low sagebrush site had the least biological crust cover, which did not differ due to livestock exclusion. A gravelly soil surface and dominance of rhizomatous grasses appear to limit biological crust development on the low sagebrush site.