California coastal sage and chaparral ecoregion
|California coastal sage and chaparral|
Chaparral and pine forests in the Cleveland National Forest
|Biome||Mediterranean forests, woodlands, and scrub|
|Area||36,288 km2 (14,011 sq mi)|
|Countries||United States and Mexico|
|States||California and Baja California|
California coastal sage and chaparral is part of the Mediterranean forests, woodlands, and scrub biome. It covers about 14,000 square miles (36,000 km2) of coastal terraces, plains, and foothills south to the Punta Baja in northern Baja California, including the southern slopes of the Santa Monica Mountains, Santa Ana Mountains, and Santa Rosa Mountains, the San Joaquin Hills, the Channel Islands, Guadalupe Island, and Cedros Island. The climate is Mediterranean, with cool, wet winters and hot, dry summers with fog.
The plant species of the California coastal sage and chaparral ecoregion are diverse, with high endemism. The main plant communities are Coastal sage scrub, California coastal prairie, and Northern coastal scrub.
Prominent coast adjacent species include: California sagebrush (Artemisia californica) and brittlebush (Encelia californica), along with California buckwheat (Eriogonum fasciculatum) and Munz's sage (Salvia munzii).
At the southern areas of this coastal ecoregion, cacti and succulents can be found, such as: Shaw's agave (Agave shawii), coastal dudleya (Dudleya caespitosa), coastal cholla (Cylindropuntia prolifera), golden cereus (Bergerocactus emoryi), and other prickly pear (Opuntia), Yucca and Dudleya species.
Some of the endemic plants to the ecoregion's southern coast zone include: San Diego thornmint (Acanthomintha ilicifolia), San Diego ambrosia (Ambrosia pumila) and San Diego barrel cactus (Ferocactus viridescens).
Higher up from the shoreline the slopes are densely covered in Chaparral shrubs, such as: chamise (Adenostoma fasciculatum), and many California lilac (Ceanothus) and manzanita (Arctostaphylos) species. Chaparral Yucca (Hesperoyucca whipplei) is commonplace throughout the climate zone.
Still higher are mountain conifers such as the huge sugar pine (Pinus lambertiana), ponderosa pine (Pinus ponderosa), Jeffrey pine (Pinus jeffreyi), Coulter pine (Pinus coulteri), and incense cedar (Calocedrus decurrens). Endemic cypress (Cupressus) species include: the Monterey cypress (Cupressus macrocarpa), Gowen cypress (Cupressus goveniana), and Sargent's cypress (Cupressus sargentii).
Riparian canyon bottoms can have California sycamores (Platanus racemosa). California oak woodlands are at many elevations in less xeric locations, with species such as the coast live oak (Quercus agrifolia). Valley oaks (Quercus lobata) once covered the adjacent sheltered plains, such in the Los Angeles basin and San Fernando Valley.
The Channel Islands are mostly covered in coastal sage and chamise chaparral with some oak woodland including endemic and/or rare: buckwheats (Eriogonum spp.), oaks (such as island oak—Quercus tomentella), and Dudleya species restricted to these islands.
In and around these different habitats this diverse ecoregion also contains 'patches' of stream-riverside riparian zone oak-sycamore woodlands, native and introduced species grasslands, and serpentine barrens. Seasonal wetland habitats include intermittent creeks, ponds, vernal pools, and floodplains.
Wildfires are part of the natural fire ecology throughout the ecoregion. Habitats of this hot, dry coast must survive and revive following the regular forest fires, and the dominant plant species have adapted to do that.
Wildlife found here includes the Hermes copper and Quino checkerspot butterflies among the 200 butterfly species found here. Other animals include the rosy boa, red-diamond rattlesnake (Crotalus ruber), the San Diego subspecies of the coast horned lizard and the western banded gecko (Coleonyx variegatus), San Diego pocket mouse, Stephens' kangaroo rat (Dipodomys stephensi), and Merriam's kangaroo rat, western patch-nosed snake (Salvadora hexalepis), and cheese-weed moth lacewing (Chrysoperla species). Vernal pools in the ecoregion are home to Riverside fairy shrimp (Streptocephalus woottoni).
The California gnatcatcher is a small bird, endemic to this coastal ecoregion, which has been protected as its habitat is now designated an Important Bird Area. Other birds found here are the endemic Nutall’s woodpecker (Picoides nuttallii) of the oak woodland, and the coastal populations of the protected cactus wren (Campylorhynchus brunneicapillus).
Threats and preservation
This attractive coastline is highly vulnerable to urban, recreational, and agricultural development and only 15% of original habitat is intact. Habitats are vulnerable to livestock grazing, which has removed much native vegetation on the Channel Islands, such as Santa Cruz where sheep were grazed for over 100 years. Another threat ironically is fire control, which only allows the amount of dry material in the forest to build up resulting eventually in massive fires. However, in many chaparral regions such as the Santa Monica Mountains, increased fire frequency is the larger concern because fire return intervals in mature chaparral communities should be 30-150 years unlike much of the region which often has return intervals of 20 years or less.
There are patches of coastal sage scrub in Marine Corps Base Camp Pendleton, the Santa Monica Mountains, the San Joaquin Hills near Laguna Beach, and the Irvine Ranch in Orange County, California. Protected areas include the Torrey Pines State Reserve, the Santa Rosa Plateau Reserve, and Santa Cruz Island. Important Bird Areas in Mexico include Isla Guadalupe and Isla Cedros, and parts of Sierra de Juárez and Sierra de San Pedro Mártir.
Additional patches of coastal sage scrub exist in Southern California in the Angeles National Forest.
- "Atlas of Global Conservation". The Nature Conservancy. Retrieved 2017-05-08.
- "California coastal sage and chaparral". Terrestrial Ecoregions. World Wildlife Fund.
- Castellanos, A. V.; Mendoza, S. R. (1991). "Aspectos Socioeconómicos". In Ortega, A.; Arriaga, L. La Reserva de la Biosfera "El Vizcaíno" en la Peninsula de Baja California. México (in Spanish). 4. Centro de Investigaciones Biológicas de Baja California Sur. pp. 35–52.
- "Wildfire in the Chaparral". California Chaparral Institute. Retrieved 2016-07-30.
- "Mean Fire Return Interval". Santa Monica Mountains National Recreation Area. National Park Service. Retrieved 2016-07-30.