Guide to Visiting California's Grasslands

Visiting Serpentine Grassland

Redwood Regional Park, Skyline Serpentine Prairie

Location

Redwood Regional Park is near Oakland and the Skyline serpentine prairie is on the ridge of the park’s southwest boundary. From Highway 13, take the Redwood Road exit and go east on Redwood Road. Turn left on Skyline Blvd., go half a mile and then turn right into the entrance and parking area, which is next to the Richard Trudeau Training Center, 11500 Skyline Blvd.. The serpentine grassland site is just behind the training center; follow the Dunn trail down the hill behind the building. More information is available at http://www.ebparks.org/parks/redwood.htm or 510-562-7275.

Overview

The 1,836-acre Redwood Regional Park is part of the East Bay Regional Park District. The park has redwoods, other evergreens, chaparral, and an area of serpentine soil that supports an exceptionally diverse stand of native grasses.

Best Time To Visit

March-May: During the spring, the serpentine grassland's perennial grasses are green and flowering, and native flowers are blooming.

Site Description

Geography and Climate
The elevation is about 1,000 feet and the grassland site has clay and serpentine soils. The clay-and-serpentine soil is saturated in the winter and dries out in the spring. Redwoods don't grow in this area of the part because the clay soils dry out too fast for the roots of their seedlings to grow, and because they can't tolerate extended periods of soil saturation. In addition, forests are extremely uncommon on serpentine soil because they have low nutrient levels.
Serpentine soils are derived from serpentine rock, which is smooth, shiny and blue-green, and is the state rock of California. Serpentine soils tend to dry out quickly; be low in nutrients such as calcium, nitrogen and phosphorus; and be high in heavy metals such as chromium, molybdenum and nickel. While these high concentrations of heavy metals make serpentine soil toxic to most plants (such as blue and live oaks), many species have adapted to thrive there. Some plants can grow both on and off serpentine (such as California bay, gray pine and toyon) and about a tenth of California's 2,300 endemic plant species live only in serpentine areas.
The area is semi-arid, with cool winters (40-60 F) and mild summers (50-75 F).

Plant Communities
The serpentine prairie includes a wide variety native grasses including Meadow barley, Bentgrass, California brome, Purple needlegrass, California oatgrass, Big squirreltail and Blue wildrye. Other rare plants include the spring wildflower, Clarkia franciscana.
On Redwood Road, about 1.5 miles west of the Skyline serpentine prairie, there is a hidden redwood forest with peaceful groves of 150-foot trees.

Animals
The park's wildlife includes rare species such as the golden eagle and Alameda striped racer snake, as well as deer, rabbits, raccoons and squirrels.
Redwood Creek, which runs through the park, has rainbow trout. This fish was first identified as a distinct species from specimens caught in San Leandro Creek, which Redwood Creek feeds into. The trout that spawn in Redwood Creek migrate from a downstream reservoir outside the park, and there is a Denil Fishway near the park's Redwood Road entrance to help the trout reach their spawning grounds. Please note - fishing is not allowed in the park.

History and Current Management

The Skyline serpentine prairie is threatened by competition from non-native plants, including annual grasses, pampas grass, yellow starthistle and French broom. The East Bay Regional Park District is dedicated to protecting this site, and its management plans include doing prescribed burns every two-three years during the late summer or fall to reduce the thatch that inhibits native grass growth. In addition, the California Native Plant Society has recently held annual work days at the prairie to pull out scattered invasive plants.
Remarkably, the diversity of native grasses at the Skyline serpentine prairie has endured despite repeated disturbances over the years. In the mid-1800s, the redwood groves around the grassland were extensively logged to supply building materials for San Francisco. The area had several lumber mills as well as shantytowns to house workers. Logging the giant redwoods was difficult: the trees were so big that workers cutting into the wood had to stand on platforms or scaffolds built around their trunks. The logging era has long since passed, and today a forest of stately coast redwoods has returned.
In addition, for 30 years (1962-1992) the East Bay Regional Park Headquarters was just above the Skyline serpentine prairie. This building now houses the Richard Trudeau Training Center.

Conservation Status

While serpentine is found in several parts of the world, it covers some 2,200 square miles of California, and the North Coast Ranges have among the richest diversity of serpentine plants. While non-native plants dominate most of the grasslands in California, most non-native weeds and grasses do not grow or compete well in serpentine soils so they often have fine examples of near-original bunchgrass grasslands. However, like many of California's natural habitats, serpentine grasslands are threatened by development and competition from non-native plants.

Serpentine Grassland researched and written by Sheila Barry, July 2003.

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