Effect of Method, Site, and Taxon on Line-Intercept Estimates of Sagebrush Cover

Abstract

Sage-grouse (Centrocercus spp.) are arguably the best known of the many wildlife species that inhabit sagebrush (Artemisia spp.) ecosystems. Lack of standardization in the procedures used to assess sagebrush cover may contribute to inconsistencies in reported habitat requirements for sage-grouse and other wildlife. We compared 3 applications of the line-intercept method for 3 sagebrush taxa. We sampled 2 mountain big sagebrush (A. tridentata vaseyana) sites, 2 Wyoming big sagebrush (A. t. wyomingensis) sites, and 1 black sagebrush (A. nova) site to determine whether the results generated by the 3 methods differed. Percent cover as determined by agency methods was up to 2.6 times greater than that from research applications. Cover differences among techniques were influenced by taxa and site (P ≤ 0.001) because both affected shrub morphology. We believe it will be difficult to identify and achieve wildlife habitat guidelines for minimal sagebrush cover requirements if methodologies are not standardized.