SFPUC 2001 Alameda Watershed Management Plan

III. ENVIRONMENTAL SETTING AND IMPACTSE. NATURAL RESOURCESUrban and Cultivated AreasUrban areas are highly disturbed and consist of ornamental trees, landscaping plants, and ruralvegetable gardens. Cultivated areas occur on flat and gently rolling hills and include hay, nonnativegrasslands, orchards, nurseries, vineyards, and the site of SMP-32 (north of I-680).Invasive Plant SpeciesInvasive plant species are non-native species that have established viable populations in thecommunity. These species invade native plant communities, rapidly colonize disturbed andundisturbed sites, and compete for available resources with native species. As a result, invasivespecies decrease diversity by forming monocultures, displace native species, and typically do notprovide suitable habitat for native wildlife species.Though the number of invasive species in the Watershed is unknown, the invasive species thathave been observed include pampas grass (Cortaderia jubata), yellow star thistle (Centaureasolstitialis), and purple star thistle (Centaurea calcitrapa). Pampas grass occurs at the existingmining area, and yellow star thistle is widespread, occurring in disturbed, open grasslands.Special-Status Plant SpeciesTable III.E-1 lists special-status species that are known to occur on the Watershed or that have ahigh or moderate potential to occur based on the distance to the nearest documented occurrenceand habitat requirements. Appendix IX.B includes a list of all sensitive species known to occuror with the potential to occur in the Watershed vicinity. Both lists were compiled usingCalifornia Diversity Data Base (CDFG, 1998) search by quadrangle (i.e., La Costa Valley,Calaveras Reservoir, Mount Day and Mendenhall Springs quadrangles), California Native PlantSociety Electronic Inventory (CNPS, 1998) search by quadrangle (i.e., San Jose East, CalaverasReservoir, Mount. Day, Mendenhall Springs, Niles, Livermore, Lick Observatory and La CostaValley quadrangles), and other data sources (i.e., Environmental Science Associates, 1994;Sharsmith, 1982; Hickman, 1993; and Smith and Berg, 1992). Four of the species have formallistings as endangered or threatened under the California Endangered Species Act or FederalEndangered Species Act (Table III.E-1). These species include Presidio clarkia, Santa Clara Valleydudleya, Contra Costa goldfields, and Metcalf Canyon jewelflower. A comprehensive survey ofspecial-status plant species has not been conducted on the Watershed. However, the MetcalfCanyon jewelflower has been observed on the Watershed. The Presidio clarkia, Santa ClaraValley dudleya, and Contra Costa goldfields have a moderate potential to occur. A descriptionof each of these plants follows.Presidio clarkia (Clarkia franciscana) is federally and state endangered and is on CaliforniaNative Plant Society (CNPS) List 1B. It occurs on serpentinic soils in grassland communities.The only documented locations of this species are in the Oakland hills and Presidio NationalPark in San Francisco, California.NOP 96.223E: Alameda Watershed Management Plan III.E-7 ESA / 930385January 2001