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California Coastal Sage, Chaparral, and Oak Woodlands

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To check where a specific point lies, you can look it up in our Ecoregion Locator.

Map Legend & Subregion List

This list will help you navigate the regions in case you have problems with viewing or clicking the interactive map above.

NameColor on MapEPA Code*
Tuscan Flows6a
Eastern Hills6aa
Pleasant Valley/Kettleman Plain6ab
Temblor Range/Elk Hills6ac
Grapevine Transition6ad
Tehachapi Foothills6ae
Salinas Valley6af
Northern Santa Lucia Range6ag
Santa Lucia Coastal Forest and Woodland6ah
Interior Santa Lucia Range6ai
Southern Santa Lucia Range6aj
Paso Robles Hills and Valleys6ak
Salinas-Cholame Hills6al
Cuyama Valley6am
Carrizo Plain6an
Caliente Range6ao
Solomon-Purisima-Santa Ynez Hills6ap
Santa Maria/Santa Ynez Valleys6aq
Upper Sacramento River Alluvium6ar
Northern Sierran Foothills6b
Southern Sierran Foothills6c
Camanche Terraces6d
Tehama Terraces6e
Foothill Ridges and Valleys6f
North Coast Range Eastern Slopes6g
Western Valley Foothills/Dunnigan Hills6h
Clear Lake Hills and Valleys6i
Mayacmas Mountains6j
Napa-Sonoma-Lake Volcanic Highlands6k
Napa-Sonoma-Russian River Valleys6l
Sonoma-Mendocino Mixed Forest6m
Bodega Coastal Hills6n
Marin Hills6o
Bay Flats6p
Suisun Terraces and Low Hills6q
East Bay Hills/Western Diablo Range6r
San Francisco Peninsula6s
Bay Terraces/Lower Santa Clara Valley6t
Livermore Hills and Valleys6u
Upper Santa Clara Valley6v
Monterey Bay Plains and Terraces6w
Leeward Hills6x
Gabilan Range6y
Diablo Range6z
Santa Barbara Coastal Plain and Terraces85a
Oxnard Plain and Valleys85b
Venturan-Angeleno Coastal Hills85c
Los Angeles Plain85d
Diegan Coastal Terraces85e
Diegan Coastal Hills and Valleys85f
Diegan Western Granitic Foothills85g
Morena/Boundary Mountain Chaparral85h
Northern Channel Islands85i
Southern Channel Islands85j
Inland Valleys85k
Inland Hills85l
Santa Ana Mountains85m

* This code refers to the US EPA's Level 4 ecoregion codes for the continental U.S., see here.

About the California Coastal Sage, Chaparral, and Oak Woodlands

The California Coastal Sage, Chaparral, and Oak Woodlands is a region located in coastal California, south into northern Baja California, and extending farther inland in northern California, surrounding the central valley.

This region is treated inconsistently by different authorities. The CEC's regional classification treats it as one region, code (11.1.1), named California Coastal Sage, Chaparral, and Oak Woodlands This region is made of two discontinuous chunks, which the US EPA breaks into two regions, the Central California Foothills and Coastal Mountains (code 6), located entirely in the U.S., and farther south, the Southern California/Northern Baja Coast (code 85), located both in the U.S. and Mexico.

Here we treat these all as a single region.

Terrain is quite rugged in places, with hills or low mountains, but flat in some places, including both higher-elevation terraces and flat bottomlands. Most streams are seasonal, but some perennial streams originate farther east, in wetter, higher-elevation regions.

This region has a Mediterranean climate with mild, wet winters and dry summers. The dry season becomes longer, and total precipitation decreases as one moves south. The coastal mountain ranges also reach higher elevations in the south of this region, leading it to only exist along the coast, whereas farther north, the higher total precpitation combined with lower coastal mountain ranges leads this region to extend farther inland, entirely surrounding the central valley. Along the coast, fog provides some moisture, and high relative humidity and extensive cloud cover reduces evapotranspiration, allowing for lusher plant growth than would normally occur in a region with as little rainfall as this one.

Original cover was mostly chapparal and oak woolands, with a few local grasslands at lowest elevations, and pines at highest elevations. Small areas of Torrey Pine occur near San Diego, remnants of an older ecosystem that has declined in extent even before human influence. Canyons and moist riparian areas have richer woodlands.

This area is the most heavily urbanized part of Mediterranean California, containing nearly the entirety of the Bay Area and Los Angeles metro areas, as well as San Diego and Tijuana, numerous smaller cities, and extensive suburbanization. There is some agriculture, although much less than in the central valley. Agriculture here is diversified, growing a variety of fruits and vegetables as well as nursery products. There is also a small amount of livestock grazing. The scarcity of flat land in much of this region has placed intense pressure for development on this land; more rugged terrain such as mountains and canyons, difficult to build on or utilize for agriculture, has a greater portion of its original cover intact.

In the north, this area completely surrounds the flatter, drier, more agricultural Central Californian Valley. North along the coast, as precipitation gradually increases, this region transitions into the wetter, more forested Coast Range; to the south along the coast, precipitation decreases and this region transitions into the Baja Californian Desert. Also in the north, this region is bordered to the east by the Sierra Nevadas and to the north by the Klamath Mountains/California High North Coast Range. In the south, the region is bordered inland and at higher elevations by the Southern California Mountains, and east past that, by the Sonoran Basin and Range in the southernmost parts, and the Mojave Basin and Range slightly north of that.

References

1. Wiken, E., Griffith, G. "North American Terrestrial Ecoregions - Level III", Commission for Environmental Cooperation, (2011) Web.