West Mojave Plan FEIR/S - Desert Managers Group

Citing Bury and Luckenbach (1977), Gustafson indicated “One result [of OHV activity]is a reduction in the number of spring annuals in areas of off-highway vehicle use” and “…offhighwayvehicles detrimentally affect wildlife and creosote bush scrub habitat in the MojaveDesert.” Brooks (1999a, 2000) found non-native plant species were more common alongsideroads, and that roads served as dispersal corridors for weed species. Weeds, in turn, providefuels that result in hotter fires and relatively larger burned areas. Non-native annuals serve tospread fires between shrubs far more readily than the native annual flora (Brooks 1999b).Gustafson (1993) indicated wildfires are probably hot enough to kill seeds, sprouting shrubs, andsquirrels within their burrows. He felt this was a temporary impact that would be remedied whenvegetation became re-established.Urban Development: According to some authors, the primary threat to the MGS isdestruction and degradation of its habitat (Laabs 1998, CDFG 1992). Habitat conversion notonly decreases the amount of available habitat, it also fragments the remaining habitat, isolatingpopulations from one another. Urbanization has resulted in the loss of considerable habitat,particularly surrounding the cities of Palmdale, Lancaster, Victorville and Hesperia. Urbandevelopment results in the direct loss of habitat, and likely has effects on surrounding nativehabitats, including increased numbers of domestic and feral cats and dogs. Dumping of refuse,abandoned vehicles, and other items is often most prevalent on undeveloped lands adjacent toresidential, commercial, and industrial development (Gustafson 1993; WMP data).Gustafson (1993) concluded: “No single small development threatens the squirrel’sexistence in the region, but the total cumulative impact is greater than the sum of the individualimpacts.” He reported approximately 165,000 acres (258 mi 2 ) of urban development and215,000 acres (336 mi 2 ) of rural development occurred within the known range as of the early1990’s. Numerous historic localities for the MGS are in areas that have been converted to urbanuses. For example, about 10% of the historic MGS range has been lost to urban (6%) andagricultural (3%) uses.The MGS is not absent from all urban areas. A recent observation occurred south ofHighway 138, near Pinyon Hills, and a second occurred near an aerospace industrial complexlocated adjacent to Palmdale (Becky Jones, pers. comm., 2002). In the first case, the site andadjacent areas are comprised of extensive tracts of undeveloped lands and those with relativelylight rural development. At the second site, there are about five to six contiguous square miles ofrelatively undeveloped land, but the entire area is surrounded by urban and agriculturaldevelopment.The MGS has also been observed in residential backyards in Inyokern (Peter Woodman,2000 pers. com.), and may be seen foraging on the golf course at China Lake (Tom Campbell,pers. comm., 2002). In 1991, Laabs (Tierra Madre Consultants, Inc. 1991) tentatively identifiedan MGS burrow in the edge of an agricultural field in northeastern Lancaster. One squirrel wasrecently trapped at the proposed Hundai facility south of California City, where the consultanthad identified habitats as being marginal (Michael Connor, pers. comm., 2002). In these lattercases, the sightings are adjacent to extensive areas of undeveloped lands.Chapter 3 3-165