Protecting the remaining coastal prairie

The California Coastal Commission considers coastal prairie an “Environmentally Sensitive Habitat Area” that is protected under the California Coastal Act. The Sonoma Land Trust’s Estero Americano Preserve is one of five project sites of the Coastal Prairie Enhancement Feasibility Study (CPEFS) undergoing treatment of Holcus lanatus (velvetgrass) to determine effective strategies for controlling the exotic plant. As cattle grazing is the primary tool at the Estero Americano Preserve for coastal grassland management, the CPEFS group has installed six grazing “exclosures” to compare velvetgrass levels in grazed versus ungrazed plots. The other project sites — Bodega Marine Reserve, Bodega Head State Park, Bodega Pastures, OceanSong and OAEC — are utilizing control methods, such as mowing, sheep grazing, herbicide and hand-pulling to treat the invasive grass. Data will be collected over five years to track velvetgrass treatment success rates.

In addition to the coastal prairie velvetgrass control project, CPEFS has teamed together with multiple partners to map and classify coastal prairie resources in Marin and Sonoma Counties, prepare grassland education materials, conduct workshops and promote regional coordination, and prepare initial recommendations for coastal prairie resource conservation. The project is funded by the State Coastal Conservancy, Sonoma County Agricultural Preservation and Open Space District, UC Natural Reserve System and UC Davis Office of Research.

Coastal terrace prairie is a diverse community of perennial grasses and forbs that extends along the coastal zone from Central California to Oregon. Though only five percent of coastal prairie remains due to impacts such as urbanization, agriculture, invasive species and fire suppression over the last two centuries, these grasslands continue to support the highest plant diversity of all North American grasslands. Coastal prairie today is considered high quality if it supports 10–15 percent cover of characteristic native grasses, such as California oatgrass, tufted hairgrass, purple needlegrass, meadow barley, junegrass and native wildflowers, which persist uniformly among exotic species.

Provided by Shanti Wright, SLT stewardship project manager