West Mojave Plan FEIR/S - Desert Managers Group

Existing ACEC protection ranges from very high protection at fenced sites (i.e., DTNAand Barstow Woolly Sunflower ACECs), to very little or no protection (i.e., Harper Lake andWest Rand Mountains ACEC), to being inapplicable because the ACEC is outside the range.Only the DTNA is expressly managed for tortoise conservation; there are few formal ACECmanagement prescriptions that provide for more protection than other regulations (habitatmanagement in BLM habitat categories, USFWS critical habitat, under FLMPA).3.3.3 Mohave Ground Squirrel3.3.3.1 Mohave Ground Squirrel RangeDistribution: The entire known range of the Mohave ground squirrel (MGS) is withinthe planning area (Map 3-15) except for a very small area northeast of Searles Valley, in theNEMO planning area. The known range (Gustafson 1993) is bounded to the south by the SanGabriel and San Bernardino mountains, to the east and southeast by the Mojave River, to thewest by Palmdale and Lancaster 22 , to the west and northwest by the Sierra Nevada, to the northby the Coso Range and Olancha, and to the northeast by the Avawatz and Granite mountains onthe Fort Irwin National Training Center.The MGS has apparently been eliminated from Lucerne Valley (Wessman 1977), whereit was first trapped (at Rabbit Springs) in 1886. The most recent (1993) range map no longerincludes the western portion of the Antelope Valley east to Highway 14 between Palmdale andMojave, an area previously considered within the MGS’s range (CDFG 1980). No new datacollected since 1993 support either extensions or reductions of the known range.The known range of the MGS is probably associated with elevation, rainfall patterns,temperature, suitable plant communities and substrates, topographical barriers, and other factors.In reviewing available records, Gustafson (1993) found that the highest known elevation was at5,600 (1,728 meters) feet on China Lake NAWS (Michael Brandman Associates 1988). Laabs(1998) reported the highest known elevation at about 5,000 feet (1,524 meters), which occurredalong the eastern slope of the Sierra (Freeman Canyon, Bird Spring Canyon, and JawboneCanyon). The California Natural Diversity Data Base (CNDDB) has reported them from anelevation range of 1,800 to 5,000 feet (548-1524 meters).Rainfall patterns, temperature, and plant communities are interrelated and influenced byelevation gradients. Gustafson noted that the northwestern portion of the ranges of both theMGS and Joshua trees are coincident near Olancha. Most of the 30 plant communities where theMGS has not been observed are associated with relatively higher elevations or are outside therange (LaRue, 1998 unpublished data). The northeastern part of the range, on Fort Irwin, may belimited due to rainfall and/or topographical barriers such as mountains, major washes, dunes, anddry lakes (Gustafson 1993). Gustafson suggested that lakes of the Pleistocene era might haverestricted the current range from extending east of the Mojave River and north of the OwensValley.22 Laabs (1998) found no records for the Antelope Valley west of Palmdale and Mojave.Chapter 3 3-144