Vegetation within the project area consists primarily of Great Basin plant communities commonly found in the Mojave Desert ecosystem. The Mojave Desert extends from southern Nevada, southwestern Utah, southeastern California, and into northern Arizona. Typical vegetation types found within the project area, as described in the 2006 RMP , include moderate creosote communities, sparse creosote/bursage mix, and desert wash communities. Creosote (Larrea tridentata), white bursage (Ambrosa dumosa), Joshua tree (Yucca brevifolia), and mojave yucca (Yucca schindegera) are the most common species found throughout the project area; however, many other species are common throughout. Other less dominant components include brittlebush (Encelia frutescens), four-wing saltbush (Atriplex canescens), burrobush (Hymenocilea salsola), cat-claw (Acacia greggii), spiny horsebrush (Tetradymia spinosa), and a variety of cactus (cholla, barrel, and hedgehog cactus). In addition, a number of non-native trees are established throughout the developed portions of the property, including mulberry (Morus sp.), fremont cottonwood (Populus fremontii), cypress (Cupressus sp.), arborvitae (Thuja occidentalis), and box elder (Acer negundo). A list of all species observed during the reconnaissance surveys are provided in Appendix D, Observed Plant Species List.

Reconnaissance level field surveys were performed to supplement the RMP plant community descriptions. Field surveys were conducted on June 7 2006 and between May 28, 2009 through May 30, 2009. In general, species composition and distribution were observed to vary across the project area based on soil type, available soil moisture, elevational gradient, slope aspect, and geomorphology. Like many desert environments, plant density is relatively sparse with exposed soil and rock being the predominant cover.

During the reconnaissance level field surveys, many annual and perennial forbs had senesced or were at the tail end of their life cycle for the year. Most of these species flower between March and May following the cooler temperatures and precipitation in winter and spring. During the field visits, it was noted that approximately half of the 40-acre parcel has been developed as part of the historic cattle operation and that much of the 40-acre parcel appears to have been modified at some point, as indicated by lower species diversity as compared to the surrounding parcels. Each of the plant communities are described below based on adapted GAP and RMP vegetation descriptions and field surveys. The Nevada Natural Heritage Program (NNHP) mapping shows 95 percent of the plant community as Mojave mixed scrub, 2 percent as Blackbrush Grassland, and 3 percent as Mojave desert scrub creosote-bursage. A summary of the plant communities are provided in Table 3.4, “List of Special Status Plant Species”.

Mojave Mixed Scrub – The Mojave mixed scrub is characterized by the occurrence of creosote (Larrea tridentate) in association with a number of species, including bursage, Joshua tree, blackbrush, Mojave yucca, desert thorn (Lycium spp.), shadscale (Atriplex confertifolia), hopsage (Grayia spinosa), ratany (Krameriaceae parvifollia), and Mormon tea (Ephedra nevadensis). The primary shrub species associated with this community are blackbrush, brittlebrush (Encelia farinosa), burro bush, sweetbush (Bebbia juncea), eastern Mojave buckwheat (Eriogonum fasciculatum), western Mojave buckwheat (Eriogonum mohavense), and bladder sage (Salazaria Mexicana). Other associated species include numerous cacti (Echinocereus spp.), cholla (Opuntia spp.), and barrel cactus (Ferocactus cylindraceus). Grasses and forbs present include fluff grass (Erioneuron pulchellum), desert apricot mallow (Sphaeralcea ambigua), round leaf spineflower (Oxytheca perfoliata), rigid spine flower (Chorizanthe rigida), skeleton weed (Eriogonum brachypodium), desert trumpet (Eriogonum inflatum), California cottonrose (Filago californica), cryptantha (Cryptantha spp.), and rattlesnake weed (Chamaesyce albomarginata). Many of the disturbed areas such as corrals, parking areas, etc. were covered with dense mats of red-stemmed filaree (Erodium cicutarium).

Creosote-Bursage – This shrubland is dominated primarily by creosote and white bursage. Other less dominant shrub species include blackbrush, Mormon tea, indigo bush, shadscale, hopsage, desert thorn, ratany, burro bush, and brittlebush. Joshua tree, Mojave yucca, and numerous cacti species are found throughout.

Blackbrush – Blackbrush is the dominant species in this community, occurring in Mojave Desert transition areas. Primary associated shrub species include spiny hopsage, Mormon tea, shadscale, desert thorn, and creosote. Joshua tree and yucca are also present, but in less density than the other two communities.