The majority of this IBA is comprised of the Spring Mountains National Recreation Area, administered by the US Forest Service. The Spring Mountains of southern Nevada are located near the southernmost border with California. Pahrump Valley and the Amargosa River basin lie to the west and Las Vegas Valley, draining to the Colorado River, lies to the east.
The Spring Mountains are probably the most biologically diverse of all Nevada's mountain ranges. This diversity is reflected by the number of tree species known from the range (37), more than any other mountain range in Nevada. There are probably more than 1,000 species in the Spring Mountains, and thus it possesses about one third of the entire Nevada flora, including many endemic species.
The vegetation series in the Spring Mountains begins at its lowest slopes with creosote bush -white bursage shrublands of the Lower Mojavean Zone. Moving upward in elevation, the vegetation community phases into blackbrush shrublands, then into pinyon-juniper woodlands. Curlleaf mahogany becomes a component of this forest at its higher elevations. Above the pygmy forest, the montane zone contains large woodlands of mountain mahogany, mixed conifer forests consisting of ponderosa pine and white fir. At slightly higher elevations, these forests also include limber pine, bristlecone pine in the overstory, and common juniper in the understory. Small aspen stands occur on north and east aspects in this zone. A tiny alpine zone occurs on Charleston Peak, and thus the Spring Mountains contain all the vegetation zones in Nevada except for the sagebrush and absolute desert zones. (Biological Resources Research Center 2004).
Land use patterns within this IBA are dictated by the management of the Spring Mountains Special Resource Area. Uses include nature conservation and research, Wilderness, tourism and recreation, and limited urban/suburban development.
Interestingly, the bird community of the Spring Mountains is in many ways its least unique feature. The noteworthy endemism belongs to other, less mobile flora and fauna. Nonetheless, the area is remarkable for the type of habitats it provides, many of which are otherwise largely absent from the Mojave Desert. Flammulated Owls breed in the coniferous forests, and most other species characterizing this site are associated with this habitat type. A week raptor migration passes down the range in fall and is most visible in Potosi Pass.
Flammulated Owl population dynamics.
1/2 pinyon-juniper and 1/2 fir-pine.