Banner Image by Brent Reed


Santa Rosa Plain Ecosystem

The Santa Rosa Plain, situated at the heart of the Laguna de Santa Rosa watershed, is a vast oak savannah grassland, dotted with vernal pools and swales that become visible in the Spring time once they fill with water and support a characteristic community of endemic plants and animals. The Santa Rosa Plain extends west of Santa Rosa, north of Cotati, south of Windsor and is bordered by the Laguna de Santa Rosa and Sebastopol on its western side.

Valley Oak Savannah

Valley oaks are found scattered across the grasslands and along creek corridors in the Santa Rosa Plain. The majority of mature trees are in an age class of 200 years and older. Valley oak populations have declined since the gold rush era due to removal for fuel, agriculture and urban development. The remaining trees are challenged by summer irrigation, compaction in the root zone, competition from introduced species and continuous grazing. Another challenge facing the savannah grassland are the proliferation and spread of non-native annual grasses that threaten native grassland species.

Santa Rosa Plain Vernal Pool Ecosystem

Vernal pools are temporary wetlands that once occurred throughout California grasslands, providing habitat for many rare and endemic organisms. Today, less than 10% of vernal pool habitat remains across the state, and native pool species are in decline. The Santa Rosa Plain (SRP) has lost 85% of its vernal pools within the last 50 years, having undergone a significant transformation, changing from a largely rural residential, diverse agricultural, and extensive open space, with seasonal and perennial wetlands, vernal pool grasslands, and oak woodlands, to more and more urbanization and intensive agriculture. Through this change in land use the vernal pool ecosystem habitat on the SRP has suffered great losses, significantly reducing the number of populations of local endemic animal and plant species, many now federally and state listed as endangered, such as one amphibian species:

California Tiger Salamander (Ambystoma californiense; CTS)
Demography and Breeding Phenology of the California Tiger Salamander (Ambystoma Californiense) in an Urban Landscape PDF file opens in new window
Sonoma County California Tiger Salamander Metapopulation , Preserve, Requirements and Exotic Predator Study PDF file opens in new window

and four endemic plant species:

Sebastopol Meadowfoam (Limnanthes vinculans) (

Burke’s Goldfields (Lasthenia burkei) ( )

Sonoma Sunshine (Blennosperma bakeri) (

Many-flowered Navarretia (Navarretia leucocephala ssp. plieantha) ( )

The Santa Rosa Plain Conservation Strategy
( aimsto create a long-term program to mitigate potential adverse effects on listed species due to future development on the Santa Rosa Plain. The program is based on biological goals and objectives to achieve conservation and recovery of these endangered species.

Current Studies

Population Genetics of Burke’s Goldfields, Sebastopol Meadowfoam, and Sonoma Sunshine PDF file opens in new window
‘Adopt a vernal pool’ long-term endangered species monitoring PDF file opens in new window

[ top ]