Nestled on the north end of the UCSD campus, the trail through the Ecological Park is a true hidden treasure. The trail meanders through sections of the university’s planted Eucalyptus Grove and the Ecological Reserve, which contains many native plants, birds, and reptiles.
Enter the Ecological Park at the corner of Voigt Drive and Hopkins Drive, and nearly immediately bear right along the trail paralleling Voigt Drive. Numerous sugar-gum trees (Eucalyptus cladocalyx) provide shade along the early section of the trail. This species is native to Australia and was originally planted by the City of San Diego around 1910 in anticipation of the trees serving as a valuable lumber source for the growing, yet tree-depauperate San Diego region. This is a particularly fast-growing species of eucalyptus that also resprouts after a harvest, making it seem ideal for railroad ties and other uses. However, the wood quality proved to be poor quality, in part due to this species having an optimal water requirement of about double the annual mean in San Diego. Hence, the city abandoned the groves around 1950. Since that time, the original plantings have been replaced on a wider spaced grid. The Eucalyptus Grove on UCSD’s campus is an identified overwintering site for the monarch butterfly (Danaus plexippus), making the conservation of this area important in the future despite general trends of reduced biodiversity within stands of eucalyptus as compared to native vegetation.
Stay on the wide dirt path that follows the canyon edge around the whole area. Once you emerge from under the sugar-gum canopy, start to notice many native lemonadeberry (Rhus integrifolia) shrubs. You are now in the Ecological Reserve section of the Ecological Park. This area is dominated by Diegan coastal sage scrub vegetation and contains sensitive species, such as the short-leaf dudleya (Dudleya brevifolia), which occurs only within the La Jolla and Del Mar areas and nowhere else in the world. This species is listed as endangered by the State of California. The federally threatened bird, the coastal California gnatcatcher (Polioptila californica californica) has also been known to make its home in the area. As such, it is important to stay on main trails to avoid unintended negative consequences on these and other species.
Abundant lemonadeberry transitions into dominance by chamise (Adenostoma fasciculatum) about halfway through the hike. Toyon (Heteromeles arbutifolia), black sage (Salvia mellifera), coastal sagebrush (Artemisia californica), and coast California buckwheat (Eriogonum fasciculatum) are other shrubs you will encounter. Throughout the hike, wild-cucumber (Marah macrocarpa) entwines over native shrubs and is easily recognized by large, prickly fruits hanging off the vine. If you visit the park in the spring, small, yet showy annual wildflowers like farinose ground pink (Linanthus dianthiflorus) with fringed purple petals emerging from a bright yellow center, California sun cup (Camissoniopsis bistorta) identified by four yellow petals, each with a small brown dot near the throat of the flower, and several species of popcornflower (Plagiobothrys spp.) with small, white flowers may greet you. If it is a particularly wet spring, look for the liverwort called California asterella (Asterella californica), ferns, miner’s lettuce (Claytonia perfoliata), and mosses along the trail.
The trail enters the Eucalyptus Grove once again, and you will shortly be back at the entrance of the Ecological Park. To extend your walk by 0.6 mile and make your final distance 2.4 miles, walk along the paved sidewalk along Hopkins Drive toward Geisel Library, where you will encounter some scrub oak (Quercus berberidifolia) and coyote brush (Baccharis pilularis). The particularly adventurous may enjoy walking around the Stuart Collection, a collection of site-specific art pieces scattered around the UCSD campus including a few just adjacent to the trail.
UCSD Ecological Park Loop
Distance from downtown San Diego: approximately 15 miles. Allow 25 minutes of driving time (La Jolla). Take I-5 N to exit 29 for Genesee Avenue. Turn left onto Genesee. After 1.0 mile, turn left onto N. Torrey Pines Road. After 0.3 mile, turn left onto UCSD Northpoint Driveway. Continue onto Hopkins Drive. Turn right onto Voigt Lane to park in Hopkins Parking Structure or left for street parking. Obey parking permit rules. This hike is best done on weekends, holidays, or outside business hours, as it can be challenging to find parking on campus. It is easier to find street parking before 10 a.m. on the weekends.
Hiking length: A 1.8-mile loop with the option of extending to 2.4 miles.
Difficulty: Moderate, with 150 ft. elevation gain/loss. No dogs allowed. No facilities.