Northern California coast

From The Encyclopedia of Earth
Jump to: navigation, search

September 17, 2009, 8:05 pm
August 30, 2012, 1:18 am
Content Cover Image

Estero Americano, straddling the Sonoma and Marin County border. @ C.Michael Hogan

The Northern California coast section encompasses diverse topography including mountains, hills, valleys and plains in the Northern California Coast Ranges and small parts of the Klamath Mountains that are sufficiently close to the Pacific Ocean for the climate to be modified greatly by marine influence. Summers are characterized by fog, cool temperatures, and higher humidity than exhibited inland. This section covers MLRAs 4, 5, 14, and 15,with the present treatment generally following that of Bailey.


Parallel ranges, folded, faulted and metamorphosed strata; rounded crests of subequal height. This unit is within the Coast Ranges Geomorphic province.


This province is characterized by Late Mesozoic eugeosynclinal rocks of the Franciscan Formation, and shelf and slope sedimentary rocks.

Soil Taxa

Dominant soil types include Alfisols, Inceptisols, Mollisols, Spodosols (Pygmy Forest), Ultisols and Vertisols in combination with isomesic, mesic or thermic soil temperature regimes, and aquic, udic, ustic or xeric (in the moist end of range) soil moisture regimes.


Predominant natural communities include forests dominated by oaks and redwoods including: the Redwood series, Douglas-fir - tanoak series, Oregon white oak series, Tanoak series and Coast live oak series; Leather oak is often found in more serpentine soils locations such as the Cedars in Sonoma County. There are also coastal grasslands often described as the Purple needlegrass series.

The following series are found throughout the section and are not restricted to, or extensive in any subsection. Series dominated by alien species are not listed under subsections unless they are extensive and stable.

  • Series dominated by exotic plants (Alien species): Broom series, Giant reed series, Cheatgrass series, Eucalyptus series, Iceplant series, Kentucky bluegrass series, Pampas grass series and Yellow bush lupine series north of Sonoma County.
  • Series that can occur in all subsections, but are not extensive: Bulrush series, Bulrush - cattail series, Burreed series, California oatgrass, Cattail series, Common reed series, Creeping ryegrass series, Duckweed series, Fen habitat, Idaho fescue series, Mosquito fern series, One-sided bluegrass series, Pondweeds with floating leaves series, Pondweeds with submerged leaves series, Sedge series, Spikerush series, Tufted hairgrass series and Yellow pond-lily series.
  • Series dominated by willows restricted to riparian settings: Arroyo willow series, Hooker willow series, Mixed willow series, Narrowleaf willow series, Pacific willow series, Red willow series, Sandbar willow series and Sitka willow series.
  • Disturbance series of short-lived vegetation: Blue blossom series, Coyote bush series away from the coast, Deerbrush series, Eastwood manzanita series, Red alder series away from the coast, Tobacco brush series and Wedgeleaf ceanothus series.


Mammals include Roosevelt elk, black-tailed deer, black bear, mountain lion, coyote, bobcat, raccoon, skunks, marten, fisher and river otter. Birds include eagles, hawks, owls, peregrine falcon, osprey and a variety shorebirds and waterfowl along the coastal part of the section. Species of concern include marbled murrelet and northern spotted owl. Coastal streams and rivers are used by anadromous fish.


Altitudes within this region of California span a range from sea level to 3000 feet.


Precipitation within the region consists mostly of rainfall, but has minor contributions from snowfall and fog condensation, with a total annual amount of 20 to 120 inches.


Mean average daily temperature average from 40° to 60°F, depending on latitude and distance inland. Summer daytime [[temperature]s] are often modified by fog and sea breezes.

Growing Season

The agricultural cultivation season spans 225 to 310 days.

Surface Water Characteristics

Many slow or relatively slow streams and rivers in alluvial and weak bedrock channels flowing directly to the Pacific Ocean. Most terminate in tide affected brackish estuaries.

Disturbance Regimes

  • Fire: Historic occurrence is changing from frequent, low to high intensity surface fires to infrequent, moderate to high intensity stand replacing fires.
  • Overgrazing: Overgrazing by domestic livestock has caused extensive soil loss as well as decline of numerous vegetative species.
  • Seismic Activity: Seismically active area with strong shaking and ground rupture.
  • Flooding: Periodic flooding occurs along major drainages. Landslides initiated by climatic, seismic and human events are common in steep areas of the section.

Land Use

Composition and Successional sequence of some communities (primarily grassland communities) has changed because of numerous alien species of plants and animals introduced between the early 1800’s and early 1900’s related to grazing and forestry. The southern part of the section, and some of the northern part contains expanding urban areas.

Cultural Ecology

Humans have been utilizing the area for some 8,000 to 10,000 years, and have been an integral part of north coast ecology for some 2,000 to 3,000 years, thriving on the diversity of habitats from ocean and estuary to forest, and intensively gathering numerous resources. The variety of Northwest California ethnographic cultures is the most complex in the United States, reflecting diverse prehistoric and historic uses, practices, and human adaptations. The fur trade was a unique part of northwest coast early history, and later lumbering and agriculture were the main economy. Contemporary attitudes and beliefs are dichotomized between emphasis on amenity/newcomer and commodity/long-time resident values, but all overlain by a rural lifestyle, even in the trendy Marin headlands north of San Francisco. The economy is diverse, ranging from San Francisco Bay Area financial and entertainment industries to rural agriculture, forestry and fishing; tourism and recreation are important industries.


The Northern California Coast section is divided into 13 subsections.


  • J.S. Diller (1915) Guidebook of the Western United States: Part D. The Shasta Route and Coastline, U.S. Geological Survey, Bulletin 614,
  • Robert F.Heizer and Albert B.Elsasser. 1980. The Natural World of the California Indians. Berkeley: University of California Press. ISBN9780520038967.
  • John Thomas Howell. 1970. Marin flora: manual of the flowering plants and ferns of Marin County. 366 pages
  • C. Michael Hogan. 2008. Ring Mountain, The Megalithic Portal.
  • United States Forest Service. "Sierra Nevada". Ecological Subregions of California.
  • National Park Service. 2006. "Smith River California". National Wild and Scenic Rivers System.
  • Stare of California. 2003, Draft Environmental Impact Report, Lake Earl Wildlife Area SCH No. 1989013110, California State Clearinghouse, Sacramento, CA
  • State of California. 1974. State Water Resources Control Board Water Quality Control Policy for the Enclosed Bays and Estuaries of California
  • U.S.Forest Service. Crescent City Plain

Return to Ecoregions of the United States

Disclaimer: This article contains some information that was originally published by the United States Forest Service. Topic editors and authors for the Encyclopedia of Earth have significantly edited its content and added substantial new information. The use of information from the United States Forest Service should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.
  • John Thomas Howell. 1970. Marin flora: manual of the flowering plants and ferns of Marin County. 366 pages
  • C. Michael Hogan. 2008. Ring Mountain, The Megalithic Portal.


Service, U. (2012). Northern California coast. Retrieved from