SU0015801 - Laserfiche WebLink

Home Browse Search

Rare Plant Survey Report Griffith Energy Storage Project 4.0 SURVEY RESULTS The Project site is undeveloped other than three small residential areas.All undeveloped areas of the site consisted ofAvena spp. -Bromus spp. herbaceous semi-natural alliance. Cattle were actively grazing the site during the rare plant survey in March 2022. Grazing on the site has greatly reduced the cover of non-native grasses such as slender wild oat(Avena barbata) and bromes(Bromus spp.) as compared to the surrounding non-grazed areas offsite. Most of the site cover was comprised of non- native redstem filaree (Erodium cicutarium)with some small patches of non-native cheeseweed (Malva parviflora), black mustard (Brassica nigra),and greenstem filaree (Erodium moschatum). By September 2022,vegetation cover in undeveloped areas of the site was comprised almost entirely of dead non-native annuals such as filarees and mustards with some sprouts of Russian thistle(Salsola sp.). Non-native olive trees(Oleo europaea) and pepper trees(Schinus sp.) and ornamental pine trees (Pinus sp.)were found in residential areas. No sensitive natural communities were found during the rare plant surveys. CNDDB records from 2003 documented an existing offsite population of big tarplant(CRPR 1B.1) approximately 25 feet west of the Project site,across Midway Road (CDFW 2022).This existing offsite population was observed during the September 2022 survey since it occurs directly across from the Project site. Multiple 1.6 meters tall big tarplant and many other shorter big tarplant were observed in this offsite area. Similar to the Project site,this area consisted ofAvena spp.-Bromus spp. herbaceous semi-natural alliance, but had higher cover of non-native grasses than the site and less intensive cattle grazing. One rare plant species, big tarplant,was found on the western portion of the Project site during the September 2022 rare plant survey.This species was found onsite in erosional areas where soil was disturbed and supported less herbaceous cover.This species is generally known to occur in grasslands and disturbed areas such as burned areas. Specimens of this plant were sent to Dr. Bruce Baldwin of the Jepson Herbarium at University of California, Berkeley and it was verified to be the rare big tarplant by Dr. Baldwin (Baldwin 2022). Two populations of big tarplant were observed within the Project site.The specific locations and boundaries of these populations are shown in Figure 4. Population 1 consisted of 395 individuals and was 0.09 acres in size. Population 2 consisted of 167 individuals and was 0.15 acres in size. Both populations occurred in ephemeral erosional features that had higher cover of bare soil relative to other areas of the Project site.Although this species can grow to over 1.8 meters tall, individuals on the Project site were stunted, likely due to disturbance by cattle grazing, and were up to 0.6 meters tall. Herbivory by cows was observed on some big tarplant individuals. Yellow star-thistle(Centaurea solstitialis),a species rated "High" by the California Invasive Plant Council (Cal-IPC)was found onsite.Yellow star-thistle was predominantly found along fencelines and in areas with stormwater runoff such as near roads. Species rated High by the Cal-IPC have severe ecological impacts on physical processes, plant and animal communities,and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment,and most are widely distributed ecologically. All plant species observed in the Project site are listed in Table 1. OTETRA TECH 8 July 2023