California coastal sage and chaparral ecoregion

California coastal sage and chaparral
Chaparral and pine forests in the Cleveland National Forest
Ecology
Biome	Mediterranean forests, woodlands, and scrub
Bird species	291[1]
Mammal species	74[1]
Geography
Area	36,288 km2 (14,011 sq mi)
Countries	United States and Mexico
States	California and Baja California
Conservation
Habitat loss	26.515%[1]
Protected	17.83%[1]

California coastal prairie in Sonoma County

Southern coastal scrub in the Santa Monica Mountains National Recreation Area

The California coastal sage and chaparral, a sub-ecoregion of the California chaparral and woodlands ecoregion, is found in southwestern California and northwestern Baja California in Mexico.

Location

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.^[2]

Flora

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.

Fauna

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.^[3] 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.^[4][5]

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.

References