The Great Basin is characterized by strong patterns of precipitation along approximate north-south gradients (Miller and others, 2013). Hence, we used a hydrographic boundary layer developed by Mason (1999), to divide the region-wide extent of sage-grouse habitat mapping analysis into North and South regions that align coarsely with respective mesic (wet) and xeric (dry) regions of the state. Flood regions are based largely on patterns of snowmelt, summer thunderstorms or cyclonic rainfall, and the 8-digit Watershed Boundary Dataset (WBD, 2015) was used to select appropriate watersheds within our mapping extent that corresponded to the Mason (1999) boundary. Slight adjustments, made in ArcMap 10.3, included joining region 2 and 3 to comprise the majority of the North region (where a relatively low number of sampled sites precluded keeping regions 2 and 3 separate), and pooling the more xeric Owyhee Desert (located in the center of the northern part of Nevada) within the drier South region. Use of the hydrographic boundary allowed for an accounting of broad-scale variation in habitat availability and selection patterns for sage-grouse (for example, habitat classified as highly suitable in wet areas could be classified as less suitable in drier areas because these habitats are less available). Interim statewide habitat suitability maps were clipped by the hydrographic boundary and relativized according to their respective maximum values for map classification purposes (see Coates and others 2014), the independent set of sage-grouse telemetry points was also split by the hydrographic boundary. For the spring map, 837 points informed the North region while 794 informed the South region. For the summer map, 604 points informed the North and 794 the South. For winter, 326 informed the North and 411 the South. For our composite annual map made from the multiplicative product of the seasonal maps, 1767 points were used for the North and 1999 for the South. References: Coates, P.S., Casazza, M.L., Brussee, B.E., Ricca, M.A., Gustafson, K.B., Overton, C.T., Sanchez-Chopitea, E., Kroger, T., Mauch, K., Niell, L., Howe, K., Gardner, S., Espinosa, S., and Delehanty, D.J. 2014, Spatially explicit modeling of greater sage-grouse (Centrocercus urophasianus) habitat in Nevada and northeastern California—A decision-support tool for management: U.S. Geological Survey Open-File Report 2014-1163, 83 p., http://dx.doi.org/10.3133/ofr20141163. ISSN 2331-1258 (online) Mason, R.R. 1999. The National Flood-Frequency Program—Methods For Estimating Flood Magnitude And Frequency In Rural Areas In Nevada U.S. Geological Survey Fact Sheet 123-98 September, 1999, Prepared by Robert R. Mason, Jr. and Kernell G. Ries III, of the U.S. Geological Survey; and Jeffrey N. King and Wilbert O. Thomas, Jr., of Michael Baker, Jr., Inc. http://pubs.usgs.gov/fs/fs-123-98/ Miller RF, Chambers JC, Pyke DA, Pierson FB, Williams CJ. 2013. A review of fire effects on vegetation and soils in the Great Basin Region: response and ecological site characteristics. Gen. Tech. Rep. RMRS-GTR-308. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. http://www.fs.fed.us/rm/pubs/rmrs_gtr308.html. WBD, 2015. Coordinated effort between the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), the United States Geological Survey (USGS), and the Environmental Protection Agency (EPA). The Watershed Boundary Dataset (WBD) was created from a variety of sources from each state and aggregated into a standard national layer for use in strategic planning and accountability. Watershed Boundary Dataset for {HUC#8}, Nevada_ST.zip [ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Hydro/FileGDB101/]. Available URL: http://datagateway.nrcs.usda.gov [Accessed 01/10/2015].

A 30 meter integer grid derived from USGS GAP data published in 2010 of sagebrush land cover within 120 meters of conifer land cover. It is one of several inputs used in the BLM FIAT analysis completed March 2015. FIAT was developed using a process designed to identify strategies that ameliorate threats to Greater Sage-Grouse (GRSG; Centrocercus urophasianus) and their habitats. While the assessment is applicable across the range of sage-grouse, the analysis is limited to Western Association of Fish and Wildlife Management Agencies’(WAFWA) Management Zones III, IV, and V (roughly the Great Basin region) because of the significant issues associated with invasive annual grasses and the high level of wildfires in this region. It incorporates emerging science, regional findings, and local data in identifying management opportunities that counter detrimental ecological trends in wildfire, invasive annual grasses, and conifer expansion. The purpose of the assessment is to identify potential project areas and management strategies in highly valued greater sage-grouse habitats which, if implemented, would reduce the threats to greater sage-grouse.

,

A raster identifying previously burned areas as being 1) recovered (to sagebrush-dominant ecosystem), 2) recovering, or 3) transitioned to annual grass-dominated.

,

As part of a 2018 Northwest Climate Adaptation and Science Center project, USGS researchers are releasing a series of spatially-explicit land-cover projections for the period 2018-2050 covering part of the northern Great Basin (Beaty Butte Herd Management Area, Hart Mountain National Antelope Refuge, and Sheldon National Refuge). The dataset contains an empirically-based business-as-usual (BAU) and an RCP8.5 climate change scenario executed for shrub, herbaceous, and bare cover types. Each scenario is executed 30 times (i.e. Monte Carlo simulations) to account for variability across historical change estimates derived from annual fractional cover maps generated by the National Land Cover Database. The map dates are 2018, 2019, 2023, 2028, 2033, 2038, 2043, 2048, and 2050. The resulting state class maps have a 300-meter resolution, and each pixel value describes the fractional cover for the modeled cover type (percent from 0-100%). The maps for each scenario are labeled accordingly: “sc” for state class, “it” for iteration (followed by iteration number), “ts” for time step (followed by simulated year). The downloadable files are organized by cover type and scenario and are available in the GeoTIF (.tif) raster file format. The 1,620 TIF raster data files were created using free state-and-transition software created by ApexRMS.