Laguna de Santa Rosa Foundation

Management Plan

Habitat Restoration

Restoring, managing & monitoring habitats

The fundamental basis for restoration activities in the Laguna is functional. Natural environments provide ecosystem services: cleaning the air and water, mod-erating flooding, and supporting diverse plant and animal communities that naturally control pests, pollinate crops, and bring beauty and mean-ing to our lives. In time, the Laguna will “restore” itself—trees will grow, wetlands will rise or fall, and creek channels will find their own meandering pathways. But such passive restoration can take a long time, and in the long intervening years, certain fish and wildlife species may be lost from the system. Natural succession in degraded systems can receive a boost through active restoration efforts.
Biological diversity is built on biological diversity.

Enhancing and Supplementing Plant Populatiions

Restoration practices focus on enhancing existing plant populations and supplementing those popula-tions with missing, but otherwise naturally occurring, native plants and trees. Stability is based on ecological feedbacks, and these feedbacks are more common among spe-cies that have evolved together over time. As a general rule, restoration projects should use locally derived sources of trees, grasses and other forbs. Restoration projects are usually initiated according to both need and opportunity, but whenever possible projects should be designed to form links between existing areas of habitat—increasing the size of large, contiguous habitat areas, or forming corridors between habitat patches.

Benefits of Monitoring

Monitoring has been chronically under-funded, and fixing this will require a reassessment—on the part of grantors—of the benefits gained through monitoring, and the risks assumed by not monitoring. The mindset that “nature will take its course and everything will be fine” is naïve and leaves otherwise successful restoration projects susceptible to long-term failure.

Vernal Pools

The Santa Rosa Plain is pockmarked with numerous vernal pools that are host to declining populations of threatened or endangered Sebastopol meadowfoam, Burke’s goldfields, Sonoma sunshine, Many-flowered navarretia, Baker’s navarretia, Dwarf downingia, Gairdner’s yampah, Douglas’s pogogyne, and Lobb’s aquatic buttercup. Vernal pools are also host to the endangered California tiger salamander.
The Laguna’s vernal pools and swales are widely recognized as a key and characteristic habitat, supporting many rare plants and animals. The unique hy-drology of these pools—holding water long past the rainy season—comes from thick underlying clay layers which in summer are cracked and dry. This harsh environment has favored the evolution of unique and specially adapted communities of plants and animals. Both CTS and the listed plant species have been heavily impacted by habitat loss and fragmentation. Vernal pools and swales exist in a matrix of uplands, and to be successful, vernal pool restoration must be accomplished in tandem with grassland restoration.

The significant loss of vernal pool habitat in California’s Central Valley underscores the importance of local efforts towards enhancement in the Santa Rosa Plain. The implementation of the Santa Rosa Plain Conservation Strategy is viewed as a creative alternative to the establishment of Critical Habitat by the US Fish and Wildlife Service. One of the most important considerations in designing this implementation plan is the need for an adequately funded preserve management team, including a preserve coordinator, scientific researchers, and a staff of vernal pool land managers.

Floodplain

ch of the higher floodplain should be restored to riparian forest—especially areas extending out from the main Laguna channel. Northern harriers, white-tailed kites, egrets, herons, and many perching birds hunt or forage on the floodplain which in the winter form large shallow lakes favored by ducks, geese and other waterfowl. Without restoration and management, the Laguna’s annual floodplains are at serious risk of being overtaken by invasive species. The greatest threats now present in the Laguna floodplain are perennial pepperweed, purple loosestrife, and several perennial bunchgrasses, including Harding grass and reed canary grass.

Open Water Wetlands

Freshwater lakes and ponds in the Laguna bottomlands provide habitat for warm water fish and their predators including, among others: eagles, black-crowned night-herons, cormorants, and pelicans. The size and location of the Laguna’s long-lost lakes are well documented in historic 19th and early 20th century maps. Interestingly, these lakes expanded and contracted more than once in the past 150 years—in part because of the dynamic nature of the Laguna—as it has been reconfigured by sediment, floodwaters, and human intervention. The Laguna’s lakes were drained and filled during the 20th century, and this habitat type is now nearly lost. One of the best opportunities for bringing back this habitat is to restore the California Dept. of Fish and Game’s Laguna Wildlife Area, located just north of Occidental Road. Accomplishing this will require good planning, extensive permitting, and the cooperation of nearby private landowners.

Perennial marshes

Tule marshes were a signature California habitat throughout the Central Valley and in other inland freshwater wetlands. They are now almost entirely gone: drained and filled, converted first to farmland and then to housing. A study of old survey maps—from the USGS and their predecessors—reveals a dramatic loss of perennial marshes in the Laguna over the past 91 years. In the most impacted area, between Oc-cidental Road and River Road, the extent of freshwater marshes has diminished significantly: in 1915 there were approximately 540 acres of shallow emergent wetlands; at the present time, 2006, only 160 acres of this habitat type remain in this reach. In addition to this dramatic quantitative loss, there has been a very significant qualitative loss: the remaining perennial marshes are heavily infested with weeds, nearby riparian forests have been further degraded due to changing water levels, and polluted water keeps predator and prey species at artificially reduced levels.

Riparian Forests

Riparian forests—the dense, multi-storied zone of willows, alders, ash, rose and berries found next to creeks—form a transition area between the saturated soils of creek embankments and the drier soils of upland meadows and prairies. There is a tremendous need for riparian restoration in the Laguna watershed. Using satellite imagery from 2001, we found that 51% of the creeks in the Laguna watershed were completely lacking in stream canopy. Fortunately, riparian areas are able to quickly restore themselves when continuous pressure from grazing livestock and human encroachment are removed. Research further shows that this type of simple, passive restoration, when compared to active restoration, can result in an equivalent amount of woody species within just a few years. But while passive restoration is a good first start, active restoration is needed in order to reestablish a wider diversity of distinct native species.

Riparian restoration integrates across almost all watershed-level restoration objectives in the Laguna: habitat connectivity, biodiversity, water quality, and flood protection. And healthy riparian areas are essential for fish and wild-life. Greater grazing control along stream banks is an essential starting point to restoring healthy riparian areas; when supplemented with well-planned active restoration, riparian forests can quickly achieve an increased diversity of plant life and an increased abundance of wildlife.

Grasslands and oak savannah

Most Laguna grasslands are working landscapes, grazed by a variety of livestock, or used for the production of feed crops. Over the next decade, citizens in the Laguna watershed will be challenged to find ways to support an economically viable ranch and dairy economy, while restoring the environmental function of grasslands. In conjunction with implementation of the Santa Rosa Plain Conservation Strategy, restoration projects that focus on grassland enhancement will become an important effort, one which can meet multiple ecosystem objectives. But grassland restoration is not easy, and to be successful intensive management will likely be needed for several consecutive years.

Present-day management efforts are mostly concerned with discouraging the growth of non-natives. Livestock grazing, along with burning, closely reproduces a natural eco-logical process. In the Laguna, like elsewhere in the world, grasses have co-evolved with grazing animals and can be very productive while retain-ing their habitat quality. Controlled burns are the most traditional and perhaps the most effective grassland management technique; correctly timed, low-intensity grass fires are effective for promoting native grasses and wildflowers. Mowing and haying are two other active management techniques suit-able for large-scale grassland restoration efforts in the Laguna.

Oak restoration

Valley oaks are emblematic of the Santa Rosa Plain and provide exceptional habitat for many species of birds, animals and insects. Garry oaks, California black and coast live are also found on the Plain, and a number of other species occur in the oak woodlands of surrounding hillsides. Throughout California, few young oaks are found among the aging groves, and in many places the oak savannah has grown thin. Regular disturbance through mowing, disking and grazing are likely the most limiting factors, destroying otherwise viable recruits. But despite recent population declines, there is real promise for oak restoration in the Laguna watershed: where seedlings are cared for, they have high survival rates and grow rapidly.

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