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Near Oceanside, California, USAPhotograph by David Olson

Western North America: Southwestern United States into northwestern Mexico Mediterranean Forests, Woodlands, and Scrub

About 14,000 square miles (36,288 square kilometers) -- about twice as big as New Jersey Critical/Endangered


· Rosy Boas and Copper Butterflies · Special Features· Did You Know?· Wild Side· Cause for ConcernMore Photos
Rosy Boas and Copper Butterflies
The California Coastal Sage and Chaparral ecoregion extends from northeastern Baja California, Mexico, northward along the Pacific into southern California in the United States. The ecoregion is bounded in the east by the Colorado-Sonora Desert and continues south as far as Punta Baja, Mexico and includes the Channel Islands (U.S.) and Cedros and Guadalupe Islands (Mexico). The landscape is one of coastal terraces, plains, and rangelands and is one of only five Mediterranean-climate ecoregions in the world. The winters are cold and humid, and the summers dry and hot. Annual average rainfall is low, between 6 and 20 inches (150 and 500 mm). Dominant plant species of the sage scrub are California sagebrushand bush sunflower. Other associated species include California buckwheat and Munz's sage. The most common succulent genera are Opuntia, Yucca,and Dudleya. In the drier southern region, one finds more cacti and succulents, including Agave shawii, Opuntia prolifera, and Bergerocactus emoryi. Chaparral dominates the higher elevations with chamise, Ceanothus, and Arctostaphylos species. Several other habitats also occur such as cypress woodlands, oak woodlands, and some conifer forests. Some notable animals in this ecoregion are the Hermes copper butterfly, Quino checkerspot butterfly, and the rosy boa.
Special Features
The California Coastal Sage Scrub and Chaparral is specially adapted to survive fires. Many plants sprout from their base after fires, and some species have seeds that only germinate after burns. Natural fires used to occur about every 20 years. Between 150 and 200 butterfly species call the sage scrub home and it is one of the riches zones of endemic bees in North America. Twenty-one species of scorpion have also been described, along with a large number of spiders. The offshore islands in this ecoregion are home to a number of rare and endemic species, including the Santa Catalina shrew, island fox, island scrub jay, and island night lizard.

Only five regions in the world have Mediterranean climates. Together, these small areas contain 20 percent of the Earth's plant species.
Wild Side
The red-diamond rattlesnake and San Diego horned lizard are two uncommon residents. The San Diego banded gecko and San Diego pocket mouse also live here, as does the San Diego horned lizard and Merriam kangaroo rat. Birds of the chaparral include the endangered California gnatcatcher, California thrasher, western scrub jay, and cactus wren. Many plant species are found only in this unusual ecoregion, including the San Diego thorn mint, San Diego ambrosia, and San Diego barrel cactus.
Cause for Concern
Livestock grazing damages fragile plant communities and important riparian vegetation. Fire suppression also causes fuels to build up and can trigger very hot, devastating fires. The biggest problem for this habitat is agricultural and urban expansion, which destroys and fragments remaining patches of chaparral. Smaller patches also experience higher impacts from introduced plants and animals. Cats, raccoons, and dogs all take a terrible toll on native animals such as reptiles and birds found in chaparral fragments. Small patches also lose species that require larger areas of habitat for survival. Existing protected areas in the states are generally too small to conserve intact natural communities, and the chaparral in Mexico needs protected areas as this area is quickly being developed.
For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.
All text by World Wildlife Fund © 2001