Type: report

Article abstract: In 2012, the Conservation Biology Institute (CBI) conducted covered species monitoring and management on the Crestridge Ecological Reserve (CER) and South Crest properties (South Crest) in San Diego County, California. Covered species monitoring focused on detecting and/or assessing the status of four MSCP covered plant species: San Diego thornmint (Acanthomintha ilicifolia), Lakeside ceanothus (Ceanothus cyaneus), variegated dudleya (Dudleya variegata), and Dehesa beargrass (Nolina interrata). Survey and monitoring strategies included presence/absence surveys, and baseline and core monitoring (including photomonitoring). One additional sensitive plant was mapped on South Crest: rush-like bristleweed (Xanthisma junceum ). Covered species management was conducted on both CER and South Crest for San Diego thommint. Presence/absence surveys were conducted for San Diego thommint, a federally threatened and state endangered species on CER and South Crest. On CER, we revisited the small population found on the slopes above Rios Canyon ('Thommint Hill') in 2010 and 2011, and searched adjacent, suitable habitat for additional stands. San Diego thommint was detected within the 2010/2011 stand boundary; six individuals were detected and five survived to produce flowers. We did not detect thornmint elsewhere onsite. Much of the formerly suitable habitat is now dominated by the nonnative grass, purple falsebrome (Brachypodium distachyon ). Monitoring within this small stand included both baseline and core monitoring to document the population boundaries and current status, including threats. Recommendations include continued monitoring and weed control efforts, and possibly, population augmentation via seed. On South Crest, surveys assessed all historic locations and potentially suitable habitat in and around Skeleton Flats. Although San Diego thornmint was not detected in historic locations, two new occurrences were detected in the low-lying hills just east of Skeleton Flats. The larger occurrence consists of approximately 950 plants and the smaller occurrence supports about 185 plants. Baseline monitoring and elements of core monitoring were conducted for these populations. Recommendations include continued monitoring and weed control efforts. Lakeside ceanothus occurs only on CER. In 2012, we continued the photomonitoring program initiated in 2010. Monitoring was conducted at seven locations and compared to 2010 and 2011 results. In three locations, nonnative pl