By Josh Bush
The Northern California Interior Coast Range Ecoregion (NCICR) is bordered on the east by the Sacramento Valley and the Northern California Coast Range to the west. The ecoregion runs in a north-south direction for about 150 miles and includes portions of Shasta, Tehama, Glenn, Colusa, Yolo, Napa, and Solano counties. Cache Creek is a prominent feature which runs directly through the heart of the ecoregion. The elevations range from 100 to 3,300 feet and average precipitation ranges from 15 to 40 inches. Humans have utilized the landscape for the last 8,000-9,000 years and have had a profound effect on the ecology of the landscape.
The NCICR falls within the rain shadow of the Northern California Coast Range and supports a diverse array of habitats including California Forest and Woodland, Western North American Temperate Grassland and Meadow, Western North American Freshwater Marsh, California Annual and Perennial Grassland, Southwestern North American Riparian Flooded and Swamp Forest, Western North American Warm Temperate Ruderal Flooded and Swamp Forest, Western Cordilleran Montane–Boreal Riparian Scrub and Forest, Western North America Wet Meadow and Low Shrub, Californian–Vancouverian Montane and Foothill Forest, California Coastal Scrub, Western Cordilleran Montane Shrubland and Grassland, and California Chaparral.
Many species most in need of conservation inhabit the NCICR. Avian species include tricolored blackbird, burrowing owl, golden eagle, bald eagle, Swainson’s hawk, black-
crowned night heron, white-tailed kite, California quail, short-eared owl, long-eared owl, peregrine falcon, savannah sparrow, spotted towhee, yellow warbler, great egret, great blue heron, Hutton’s vireo, California towhee, ferruginous hawk, loggerhead shrike, purple martin, common ensatina, and Bewick’s wren.
Reptiles and amphibians include the foothill yellow-legged frog, California red-legged frog, California tiger salamander, western pond turtle, California newt, gopher snake, and ring-necked snake. Mammals include the mountain lion, American badger, pronghorn antelope, ringtail, black-tailed jackrabbit, western spotted skunk, western skink, deer mouse, fringed myotis, and pallid bat.
In developing the SWAP 2015 Update, three factors were considered to determine the conservation target. Conservation targets can be species, habitats, or ecosystems that are the focus of conservation strategies. We considered the endemism (uniqueness to a defined geographic location), vulnerability of species found in the habitat area, and total biodiversity of the species inhabiting all habitat types within the NCICR. The California Forests and Woodlands, more commonly known as Blue-Oak Woodlands, was selected as the conservation target. This habitat is prominent throughout the ecoregion – and conservation efforts targeting blue-oak woodlands will help conserve the other habitat types interspersed within the ecoregion.
The Blue-Oak Woodlands is commonly used as rangeland. It is characterized by rolling hills with a dotted over-story of blue-oaks and an understory of exotic annual grasses introduced over decades with unknowing consequences. Some, more pristine, north facing slopes include a brush component and full blue-oak canopy, but these are rare. Typical native plant species found in this habitat are blue-oak, foothill pine, valley oak, ceanothus species, manzanita species, poison oak, California coffeeberry, creeping wild rye, blue wild rye, annual grasses and California buckeye. Meadows denuded of trees and comprised of invasive weeds are also common. Prevalent invasive plants include yellow-star thistle, medusa head, barbed-goat grass, and perennial pepperweed.
Blue-Oak Woodlands have been grazed by cattle across its entire extent. Under a proper regime of grazing using Best Management Practices (BMP), cattle can have positive effects both for the landscape and the ranchers. However, incompatible grazing has been identified as the most severe impact to the blue-oak woodland ecosystem. An improper grazing regime decreases plant diversity, impedes natural processes, and severely reduces plant recruitment throughout the woodland. Incompatible grazing and overgrazing increases soil compaction, decreases water retention, introduces invasive weeds, and can even cause intermittent stream head cutting.
Other identified impacts to the blue-oak woodland include parcelization of large properties for development, oak and brush clearing for agriculture and fuel wood, and an altered fire regime. These impacts, in combination, are long lasting and leave the woodland system as a greatly altered landscape. Further fragmentation and native plant reduction across the ecoregion and the blue-oak woodland has already, and will continue to, negatively impact the SGCN and other native species inhabiting the landscape.
The SWAP planning process has identified two main strategies to address the impacts mentioned above. The first strategy proposes the acquisition of conservation easements (CE). Conservation easements are voluntary agreements with private landowners to do certain things that will benefit fish and wildlife while allowing ongoing operations on working landscapes. By purchasing CEs on high-value habitats, the land would be protected for conservation and various habitat requirements would be incorporated into the land management practices. Landowners would contribute to, for example, creation of large contiguous corridors for wildlife movement, and allow for development and monitoring of grazing practices.
The second strategy focuses on outreach and education to the public and interested parties about the benefits of implementing grazing BMPs. Grazing BMPs could restore the blue-oak woodlands while minimizing the negative impacts such as the spread of invasive species. This strategy also encompasses demonstrating the benefits of implementing grazing BMPs both for wildlife and ranchers. These strategies, if implemented in partnership with ranchers and lessees, will be most effective and capable of providing long term conservation within the Northern California Interior Coast Range Ecoregion.