California mixed evergreen forest

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California mixed evergreen forest is a plant community that occurs in the Coast Ranges of California and southwestern Oregon.

Mixed evergreen forests occur in small areas of the Klamath-Siskiyou forests, Northern California coastal forests, and California chaparral and woodlands ecoregions. The forests of each ecoregion have a somewhat different composition.

[edit] Klamath-Siskiyou mixed evergreen forest

The mixed evergreen forests of the Klamath-Siskiyou occur above 300 meters (1000 feet) elevation, and are of four main types. Douglas-fir forests are found on gentle slopes, north-facing slopes, ridges with deep soil, and river terraces with deep sediments, usually underlain with sedimentary rocks. Coast Douglas-fir (Pseudotsuga menziesii ssp. menziesii) is the predominant tree, occupying up to 70% of the forest cover. Tree species of secondary importance are Sugar Pine (Pinus lambertiana), Ponderosa Pine (Pinus ponderosa), and White Fir (Abies concolor). Broadleaf evergreen trees are relatively few.

On granite soils, a similar species composition predominates, but with more broadleaf evergreens, chiefly Tanoak (Lithocarpus densiflora) and Canyon Live Oak (Quercus chrysolepis), along with Giant Chinquapin (Chrysolepis chrysophylla).

On steep, well drained slopes, Canyon Live Oak is the dominant species, with Coast Douglas-fir in a minor role.

On serpentine soils, mixed evergreen forests are made up of Lawson's Cypress (also known as Port Orford Cedar, Chamaecyparis lawsoniana) and Western White Pine (Pinus monticola) in moister areas, and Incense Cedar (Calocedrus decurrens), Jeffrey Pine (Pinus jeffreyi), and Knobcone Pine (Pinus attenuata) in drier areas.

[edit] Northern Coast Range mixed evergreen forest

Also called Northern mixed evergreen forest, the mixed evergreen forests of the Northern Coast Ranges of Humboldt, Mendocino, Sonoma, and Marin counties occur in cool, moist areas such as canyon bottoms. Predominant species are Coast Douglas-fir, Coast Redwood (Sequoia sempervirens), Tanoak, Pacific Madrone (Arbutus menziesii), California Bay Laurel (Umbellularia californica), Canyon Live Oak, and Interior Live Oak (Quercus wislizenii). Other species include Coast Live Oak (Quercus agrifolia), Black Oak (Q. kelloggii), and Oregon Oak (Q. garryana).

[edit] Southern Coast Range mixed evergreen forest

Also called Southern mixed evergreen forests, the mixed evergreen forests of the Southern Coast Ranges, Transverse Ranges, and northern Peninsular Ranges are restricted to cooler north-facing slopes at higher elevations. Predominant tree species include Tanoak, Pacific Madrone, Canyon Live Oak, Coast Live Oak, California Bay Laurel, Jeffrey Pine, Coulter Pine (Pinus coulteri), and Bigcone Douglas-fir (Pseudotsuga macrocarpa).