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5.7 Biological Resources

Threshold 7-1 Would the project have a substantial adverse effect, either directly
or through habitat modifications, on any species identified as a
candidate, sensitive, or special status species in local or regional
plans, policies, or regulations, or by the CDFW or USFWS?

On-Site Impacts

Special Status Plant Species
Most of the special status plants listed as having a potential to occur on the Project site in
Table 5.7-5, Special Status Plant Species would not be impacted by the Project because of
negative results of multiple focused botanical surveys and/or they are not expected to occur
on the site due to lack of suitable habitat. However, six of the eight special status plant species
found on the site, including California androsace, crownscale, round-leaved filaree, Mojave
spineflower, sylvan scorzonella, and adobe yampah would be impacted by Project
implementation, as shown in Exhibit 5.7-11a, Special Status Plant Species Observation with
Impact Boundary. The two remaining special status plant species observed on the site, Piute
Mountains navarretia and Lemmon’s syntrichopappus, were found in locations that lie
outside the proposed development footprint and would therefore not be directly impacted;
indirect impacts are not expected due to their distance from proposed development and
their occurrence within proposed open space.

California androsace is a CRPR 4.2 species. In 2008, 5 occurrences with 381 total plants were
found on the Project site. In 2015, over 29,000 individuals on 320 locations were estimated
during focused surveys, with the highest abundances on the lower hills in the northeastern
section of the Project site. The on-site population is the largest known population of the
species in the County. Project implementation would result in impacts to approximately
28,345 individuals (up to 97 percent of the on-site population) detected during focused
surveys. On Liebre Mountain, this species has been described as “occasional in grassland and
openings in scrub at the northern base of the range” (Boyd 1999). As discussed, the County
of Los Angeles Department of Regional Planning typically does not require mitigation for
impacts to CRPR 4.2 species. However, due to the lack of botanical knowledge in the region
for this species, the level of impact is difficult to ascertain and impacts are considered
potentially significant. Implementation of MM 7-1, proposed to mitigate for impacts to
special status plants, would reduce the level of impact by promoting the distribution of this
species in the Project region through the propagation of new populations in the Mitigation
Preserve. The expansion of the local population of this species is expected to increase its
potential to be sustained in perpetuity.

Crownscale has a CRPR of 4.2. Historically it has been known only from the Sacramento
Valley, San Joaquin Valley, and the Inner South Coast Ranges (Jepson Herbarium 2015). The
closest known location outside the Project boundary is approximately 30 miles to the north,
near the town of Arvin (CCH 2016). On the Project site, 2015 surveys identified 8 populations
with more than 16,000 estimated total individual plants. The largest populations were found
on alkali scalds and dry pools near the intersection of SR-138 and National Cement Plant
Road. Approximately 16,690 individuals (the entire on-site population) would be impacted
by the Project. CRPR 4.2 species are considered naturally limited in distribution and have

R:\Projects\PAS\CEN\000306\Draft EIR\5.7 Bio_051117.docx 5.7-142 Centennial Project
Draft EIR