Characteristics of Sagebrush Habitats and Limitations to Long-Term Conservation

Abstract

The distribution of sagebrush (Artemisia spp.) within the Sage-Grouse Conservation Area (SGCA, the historical distribution of sage-grouse buffered by 50 km) stretches from British Columbia and Saskatchewan in the north, to northern Arizona and New Mexico in the south, and from the eastern slopes of the Sierra Nevada and Cascade mountains to western South Dakota. The dominant sagebrush (sub)species as well as the composition and proportion of shrubs, grasses, and forbs varies across different ecological sites as a function of precipitation, temperature, soils, topographic position, elevation, and disturbance history. Most important to Greater Sage-Grouse (Centrocercus urophasianus) are three subspecies of big sagebrush (Artemisia tridentata)(basin big sagebrush [A. t. ssp. tridentata], Wyoming big sagebrush [A. t. ssp. wyomingensis], and mountain big sagebrush [A. t. ssp. vaseyana]); two low or dwarf forms (little sagebrush [A. arbuscula] and black sagebrush [A. nova]); and silver sagebrush (A. cana), which occurs primarily in the northeast portion of the sage-grouse range. Invasive plant species, wildfires, and weather and climate change are major influences on sagebrush habitats and present significant challenges to their long-term conservation. Each factor is spatially pervasive across the Greater Sage-Grouse Conservation Area 145

Effects of climatic variation and reproductive trade‐offs vary by measure of reproductive effort in greater sage‐grouse

“…obligate galliformes (Patterson 1952, Dalke et al 1963. Currently, sagegrouse are a species of conservation concern throughout their endemic range in western North America because of precipitous population declines and habitat degradation (Schroeder et al 2004, Garton et al 2011, Miller et al 2011; J. W. Connelly, S. T. Knick, M. A. Schroeder, and S. J. Stiver, unpublished manuscript). Consequently, sage-grouse were designated as endangered by the Canadian Committee on the Status of Endangered Wildlife and a candidate for protection under the Endangered Species Act (ESA) by the U.S.…”

Bird–Habitat Relationships in Interior Columbia Basin Shrubsteppe

“…Few of these landscapes remain intact post Euro-American settlement (Miller and Eddleman, 2001;West, 1996). Fragmentation has accelerated in past decades, driven by invading annual grasses, encroaching conifer, cultivation of native rangelands, and expanding rural urban and industrial development (Miller et al, 2011). It is unlikely sagebrush systems are to return to presettlement condition as scale and magnitude of these changes greatly exceeds available financial and logistical resources (Miller et al, 2011).…”

The relative importance of intrinsic and extrinsic drivers to population growth vary among local populations of Greater Sage-Grouse: An integrated population modeling approach

“…We followed the approach developed by Knick and Hanser (2011) to estimate dispersal rates between populations within SMZs. The probability of connectivity between every pair of leks was estimated using graph theory, based on distance between known leks, the difference in size between adjacent leks, and the product of all probable steps (dispersal limited to 27 km) between the pair of leks (Knick and Hanser 2011). We expressed the estimated number of probable connective links between leks in adjacent SMZs, based on graph theory, as a proportion of all the links shown between any pair of SMZs (N = 112).…”

“…We expressed the estimated number of probable connective links between leks in adjacent SMZs, based on graph theory, as a proportion of all the links shown between any pair of SMZs (N = 112). These proportions were standardized to an estimated maximum dispersal rate at a distance of 27 km of 0.05 (Knick and Hanser, 2011). The random deviate, Ej(t), for the growth rate of the jth SMZ,   j rt , was drawn from a multivariate normal distribution with mean = 0 and the six by six variance/covariance matrix estimated from past abundance trajectories.…”

“…Movements within breeding habitat can exceed 25 km, and seasonal ranges can be > 80 km apart (Connelly et al 1988, Holloran andAnderson 2005). Populations throughout the species' range have been negatively affected by loss and fragmentation of habitat largely due to wildfire, invasive species and energy development , Miller et al 2011. Moreover, some populations have declined as a result of west Nile virus (Walker et al , 2007.…”