San Diego County, CA

Photo: Des Callaghan

March 2001
Santa Margarita Ecological Reserve (SoCal)

The Santa Margarita Ecological Reserve (SMER), midway between Los Angeles and San Diego, near Temecula, is a field station of the California State Universities administered by San Diego State University. SMER comprises a total area of 4,344 acres and was established in 1962. It is located about 3 km south of Temecula, Riverside County, California off Interstate Highway 15. The Philip C. Miller Field Station provides housing and a support facility for research.

SMER lies in the chaparral/coastal sage scrub/oak woodland vegetation zone of southern California. Elevation ranges from 150 to 700 m (500 to 2300 ft). The climate is Mediterranean, with cool wet winters and warm summers moderated by the marine influence of the Pacific Ocean that lies 18 miles (30 km) to the west. Mean annual precipitation is approximately 400 mm and the mean annual temperature about 16.4 degrees C. The topography is complex, consisting of low hills and intervening drainages. The northern portion of the station is dominated by the deep gorge of the Santa Margarita River, the last free-flowing stream in southern California. Most of the reserve is covered by low shrub vegetation, a mosaic of mixed chaparral, chamise chaparral, and coastal sage scrub with Adenostoma fasciculatum, Ceanothus crassifolius, C. tomentosus, Xylococcus bicolor, Artemisia californica, Eriogonum fasciculatum, Salvia apiana, and S. mellifera as common species. Oak and riparian woodlands are found in the deeper drainages. Quercus agrifolia, Q. engelmannii, Platanus occidentalis, and Salix spp. are common tree species.

We also explored the nearby Nature Conservancy Santa Rosa Plateau Ecological Reserve, the site of a historic ranch and one of the richest, most diverse natural landscapes remaining in southern California. This 8300-acre Reserve contains some of southern California’s last vernal pools (or seasonal ponds), which support some of the rarest plant and animal species in the region. As the water recedes in spring, “bath-tub rings” of wildflowers circle the banks of the pools with bright color. The native bunchgrass prairie on the Santa Rosa Plateau is the largest expanse of native grasslands remaining in southern California, and supports a host of native wildflowers. Many emphemeral bryophytes are found here, including the famous, rare endemic genus Geothallus which was observed in great abundance by the participants, thanks to Bill Doyle who guided us to it (see: W.T. Doyle, 1998, “Liverworts and Hornworts of the Santa Rosa Plateau Ecological Reserve, Riverside County, California.” Evansia 15: 122-124; and also: W.A. Weber, C, Bratt, & J. Larsen. 1987, “Lichens and Bryophytes of the Santa Rosa Plateau Nature Conservancy Reserve, Riverside County, California.” Evansia 4: 21-25).

Based on their collections, participants in this foray compiled a paper in Evansia [19(1): 1-8] on the bryophytes of the Santa Margrita Ecological Reserve.

River gorge
Steep walls

three people on a dock looking at something in the water
Aquatic bryophytes?