Severson J.P., C.A. Hagen, J.D. Maestas, D.E. Naugle, J.T. Forbes and K.P. Reese. 2017. Restoring sage–grouse nesting habitat through removal of early successional conifer. Restoration Ecology 25:1026–1034.
Conifer woodlands have expanded into sagebrush (Artemisia spp.) ecosystems and degrade habitat for sagebrush obligate species such as the Greater Sage-grouse (Centrocercus urophasianus). Conifer management is increasing despite a lack of empirical evidence assessing outcomes to grouse and their habitat. Although assessments of vegetation recovery after conifer removal are common, comparisons of successional trends with habitat guidelines or actual data on habitat used by sage-grouse is lacking. We assessed impacts of conifer encroachment on vegetation characteristics known to be important for sage-grouse nesting. Using a controlled repeated measures design, we then evaluated vegetation changes for 3 years after conifer removal. We compared these results to data from 356 local sage-grouse nests, rangewide nesting habitat estimates, and published habitat guidelines. We measured negative effects of conifer cover on many characteristics important for sage-grouse nesting habitat including percent cover of forbs, grasses, and shrubs, and species richness of forbs and shrubs. In untreated habitat, herbaceous vegetation cover was slightly below the cover at local nest sites, while shrub cover and sagebrush cover were well below cover at the nest sites. Following conifer removal, we measured increases in herbaceous vegetation, primarily grasses, and sagebrush height. Our results indicate that conifer abundance can decrease habitat suitability for nesting sage-grouse. Additionally, conifer removal can improve habitat suitability for nesting sage-grouse within 3 years, and trajectories indicate that the habitat may continue to improve in the near future.