Sonoma Sunshine

Blennosperma bakeri

Description

Sonoma sunshine is an annual in the aster family that grows to a height of about 12 in (30 cm). The stems and leaves are mostly hairless; the leaves are alternate and narrow. Flower heads, with yellow disk and ray flowers, bloom in March and April. It is distinguished from similar members of its genus by the presence of red stigmas in the ray flowers. It is also known by the common name, Baker's Sticky Seed.

Habitat

Baker's sticky seed is found only in vernal pools and other seasonal wetlands in California's Cotati and Sonoma valleys, which lie north of San Francisco. These wetlands occur where a nonporus layer, such as clay, hardpan, or volcanic stone, lies beneath surface depressions. In these places, winter rains form pools which gradually dry out during the spring and summer. This unique habitat will not support plant species that are intolerant of inundation or aquatic species that require permanent standing water. In the Cotati Valley, vernal pools form on Huichica loam and Clear Lake clay soil types where there is an impervious layer 2-3 ft (0.6-1 m) below the surface.

Sonoma sunshine is sometimes found together with two other federally Endangered plants: Burke's goldfields (Lasthenia burkei) and Sebastopol mead-owfoam (Limnanthes vinculans). The portion of the valley where these three species occur is about 16 mi (26 km) long and 5-11 mi (9-18 km) wide. It is bounded on the north by the town of Windsor; on the south by the town of Hessel; on the west by the Laguna de Santa Rosa, a tributary of the Russian River; and on the east by the foothills of the Sonoma and Mayacmas Mountains.

Other plants associated with these vernal pools include fringed downingia (Downingia concolor); Navarretia spp.; smooth lasthenia (Lasthenia glaberrima); and Lobb's buttercup (Ranunculus lobii).

Distribution

Sonoma sunshine was first collected in 1946. It is endemic to Sonoma County and has been found nowhere else.

At present, there are 30 known populations of Sonoma sunshine in vernal pools in the southern portion of the Cotati Valley and four populations in Sonoma Valley. These scattered sites stretch from the vicinity of Santa Rosa south to the town of Hessel. Most of the vernal pools are on private land. One site, the Todd Road Reserve, is owned by the California Department of Fish and Game. It contains populations of Sonoma sunshine and Sebastopol meadowfoam (Limnanthes vinculans). Four other sites are owned by county or city agencies.

Threats

The overwhelming threat to Sonoma sunshine and other vernal pool species is the destruction of their unique habitats for residential and agricultural development. So far about 90% of the Cotati Valley has been developed. The pressing need for affordable housing within commuting distance of San Francisco has increased development throughout the valley.

The construction of housing developments near Santa Rosa is destroying populations of Sonoma sunshine and Sebastopol meadowfoam. Recently more than a dozen pools have been filled without the landowners obtaining permits from the Army Corps of Engineers as required by the federal Clean Water Act. In part because most of the pools are relatively small, the Corps of Engineers has been reluctant to involve itself in examining the ecological effects of destroying these seasonal wetlands. Now that Sonoma sunshine and other vernal pool species have been listed under the Endangered Species Act, the Corps is required to consult with the U. S. Fish and Wildlife Service whenever an activity might affect the species, regardless of the size of the wetland.

Sonoma sunshine faces an additional threat related to development. Because the area's population has increased, Santa Rosa is planning to expand its wastewater treatment facility. Currently, treated wastewater is used to irrigate about 4,500 acres (1,821 hectares) of cropland. Expansion plans call for the construction of a series of terraces planted with water-tolerant grasses and flooded with waste-water for treatment. The water would then be recycled for irrigation. The current plan calls for the wastewater capacity to be increased to irrigate 7,500 acres (3,035 hectares). Even if vernal pools were not directly flooded, the increase in residential and agricultural development, as well as the probable spread of the semi-aquatic grasses, would further threaten Sonoma sunshine and other vernal pool species.

A lesser threat to Sonoma sunshine is livestock grazing, which has reduced populations of vernal pool annuals at many of their historic sites.

Conservation and Recovery

The most crucial need for conservation of the Sonoma sunshine is the protection of its critical habitat from residential and agricultural development. In particular, the filling of vernal-pool habitat must be stopped. Most of the surviving habitat is privately owned and potentially threatened by various activities. This habitat should be protected by acquiring the land and designating ecological reserves, or by negotiating conservation easements with the landowners. The populations of the Sonoma sunshine should be monitored, and research undertaken into its biology, habitat needs, and beneficial management practices (including the establishment of new populations in suitable vernal-spring habitat).

Contacts

Regional Office of Endangered Species
U. S. Fish and Wildlife Service
Eastside Federal Complex
911 N. E. llth Avenue
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
http://pacific.fws.gov/

Sacramento Fish and Wildlife Office
Federal Building
2800 Cottage Way, Room W-2605
Sacramento, California 95825-1846
Telephone: (916) 414-6600
Fax: (916) 460-4619

References

Holland, R. F. 1976. "The Vegetation of Vernal Pools: a Survey." In Vernal Pools: their Ecology and Conservation, a symposium sponsored by the Institute of Ecology, University of California, Davis, May 1 and 2, 1976. Institute of Ecology Publication No. 9.

Ornduff, R. 1977. "Rare Plant Status Report for Blennosperma bakeri" California Native Plant Society, Sacramento.

Waaland, M. 1989. "Santa Rosa Plains Endangered Plant Protection Program Report, Section A." Sonoma County Planning Department and California Department of Fish and Game.