Sagebrush‐Steppe Vegetation Dynamics and Restoration Potential in the Interior Columbia Basin, U.S.A.

Abstract

Abstract: We modeled the dynamics and restoration of sagebrush ( Artemisia spp.) habitats for Greater Sage‐Grouse ( Centrocercus urophasianus) in the interior Columbia Basin and adjacent portions of the Great Basin ( referred to as the basin). Greater Sage‐Grouse have undergone widespread decline and are the focus of conservation on over 13 million ha of sagebrush steppe in the basin, much of which is managed by the U.S. Forest Service ( FS) and U.S. Bureau of Land Management ( BLM ). Consequently, we evaluated changes in the amount and quality of sage‐grouse habitat on 8.1 million ha of FS–BLM lands in the basin. Changes were estimated from historical to current conditions and from current conditions to those projected 100 years in the future under proposed management and under two restoration scenarios. These two scenarios were designed to improve long‐term (100 ‐year) projections of sage‐grouse habitat on FS–BLM lands in relation to current conditions and proposed management. Scenario 1 assumed a 50% reduction in detrimental grazing effects by livestock ( through changes in stocking rates and grazing systems) and a six‐fold increase in areas treated with active restoration relative to proposed management. Scenario 2 assumed a 100% reduction in detrimental grazing effects and the same level of active restoration as scenario 1. Under the two scenarios, the amount of FS–BLM habitat for sage grouse within treated areas declined by 17–19% 100 years in the future compared with the current period, but was 10–14% higher than the 100‐year projection under proposed management. Habitat quality under both scenarios was substantially improved compared with the current period and proposed management. Our results suggest that aggressive restoration could slow the rate of sagebrush loss and improve the quality of remaining habitat.