California mixed evergreen forest
Encyclopedia
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
, of the temperate broadleaf and mixed forests
Temperate broadleaf and mixed forests
Mixed forests are a temperate and humid biome. The typical structure of these forests includes four layers. The uppermost layer is the canopy composed of tall mature trees ranging from 33 to 66 m high. Below the canopy is the three-layered, shade-tolerant understory that is roughly 9 to...
biome
Biome
Biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems. Some parts of the earth have more or less the same kind of abiotic and biotic factors spread over a...
, that occurs in the Pacific Coast Ranges
Pacific Coast Ranges
The Pacific Coast Ranges and the Pacific Mountain System are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico...
of southwestern Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
and California, and in the Coast, Transverse, and Peninsular Ranges in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. Mixed evergreen forests occur in small areas of the Klamath-Siskiyou forests, Northern California coastal forests
Northern California coastal forests
The Northern California coastal forests are a temperate coniferous forests ecoregion of coastal Northern California, USA.-Setting:The ecoregion lies close to the Pacific Ocean, and is kept moist by Pacific Ocean storms during the winter months, and by coastal fogs in the summer months...
, and California chaparral and woodlands
California chaparral and woodlands
The California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
ecoregions. The forests of each ecoregion have a somewhat different plant community composition.
Klamath-Siskiyou mixed evergreen forest
The mixed evergreen forests of the Klamath MountainsKlamath Mountains
The Klamath Mountains, which include the Siskiyou, Marble, Scott, Trinity, Trinity Alps, Salmon, and northern Yolla-Bolly Mountains, are a rugged lightly populated mountain range in northwest California and southwest Oregon in the United States...
-Siskiyou Mountains
Siskiyou Mountains
The Siskiyou Mountains are a coastal mountain range in the northern Klamath Mountains in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately from east of Crescent City, California northeast along the north side of the Klamath River into...
occur above 300 meters (1000 ft) 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 rock
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
s. Coast Douglas-fir
Coast Douglas-fir
Pseudotsuga menziesii, known as Douglas-fir, Oregon Pine, or Douglas spruce, is an evergreen conifer species native to western North America. Its variety Pseudotsuga menziesii var. menziesii, also known as coast Douglas-fir grows in the coastal regions, from west-central British Columbia, Canada...
(Pseudotsuga menziesii ssp. menziesii) is the predominant tree, occupying up to 70% of the forest cover. Broadleaf evergreen trees are relatively few. Tree species of secondary importance are:
- Sugar PineSugar PinePinus lambertiana, commonly known as the sugar pine or sugar cone pine, is the tallest and most massive pine, with the longest cones of any conifer...
(Pinus lambertiana), - Ponderosa PinePonderosa PinePinus ponderosa, commonly known as the Ponderosa Pine, Bull Pine, Blackjack Pine, or Western Yellow Pine, is a widespread and variable pine native to western North America. It was first described by David Douglas in 1826, from eastern Washington near present-day Spokane...
(Pinus ponderosa), - White FirWhite FirWhite Fir is a fir native to the mountains of western North America, occurring at altitudes of 900-3,400 m. It is a medium to large evergreen coniferous tree growing to 25–60 m tall and with a trunk diameter of up to 2 m . It is popular as an ornamental landscaping tree and as a Christmas Tree...
(Abies concolor).
On granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
soils, a similar species composition predominates, but with more broadleaf evergreens, chiefly:
- TanoakTanoakTanoak, formerly known taxonomically as Lithocarpus densiflorus, was recently moved into a new genus, Notholithocarpus, based on multiple lines of evidence....
(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 soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s, mixed evergreen forests are made up of:
- moister areas
- Lawson's Cypress (also known as Port Orford Cedar, Chamaecyparis lawsoniana) and
- Western White PineWestern White PineWestern White Pine, Pinus monticola in the family Pinaceae, is a species of pine that occurs in the mountains of the western United States and Canada, specifically the Sierra Nevada, the Cascade Range, the Coast Range, and the northern Rocky Mountains. The tree extends down to sea level in many...
(Pinus monticola)
- drier areas
- Incense Cedar (Calocedrus decurrens),
- Jeffrey PineJeffrey PineThe Jeffrey Pine, Pinus jeffreyi, named in honor of its botanist documenter John Jeffrey, is a North American pine related to Ponderosa Pine.-Distribution and habitat:...
(Pinus jeffreyi), - Knobcone PineKnobcone PineThe Knobcone Pine, Pinus attenuata, is a tree that grows in mild climates on poor soils. It ranges from the mountains of southern Oregon to Baja California with the greatest concentration in northern California and the Oregon-California border....
(Pinus attenuata).
Northern and Central Coast Range mixed evergreen forest
These forests vary the further inland you go. Many sites in the San Francisco Bay AreaSan Francisco Bay Area
The San Francisco Bay Area, commonly known as the Bay Area, is a populated region that surrounds the San Francisco and San Pablo estuaries in Northern California. The region encompasses metropolitan areas of San Francisco, Oakland, and San Jose, along with smaller urban and rural areas...
host these forests. The moister the forest the more lush the understory.
- Those closer to the coast receiving adequate fog moisture and high rainfall generally will have:
- Coast Douglas-fir,
- Coast Redwood (Sequoia sempervirens)
- TanoakTanoakTanoak, formerly known taxonomically as Lithocarpus densiflorus, was recently moved into a new genus, Notholithocarpus, based on multiple lines of evidence....
, (Notholithocarpus densiflorus) - Pacific MadronePacific MadroneArbutus menziesii, commonly known as the Pacific Madrone, is a species of Arbutus found on the west coast of North America, from British Columbia to California...
(Arbutus menziesii), - California Bay Laurel (Umbellularia californica),
- Canyon Live Oak (Quercus chrysolepis),
- Interior Live OakInterior Live OakQuercus wislizeni, known by the common names Interior Live Oak, and Sierra Live Oak, is an evergeen oak, highly variable and often shrubby, found in areas of California in the United States. It also occurs south into northern Baja California in Mexico...
(Quercus wislizenii), - Coast Live OakCoast Live OakQuercus agrifolia, the Coast Live Oak, is an evergreen oak , native to the California Floristic Province. It grows west of the Sierra Nevada from Mendocino County, California, south to northern Baja California in Mexico. It is classified in the red oak section Quercus agrifolia, the Coast Live Oak,...
(Quercus agrifolia), - Black Oak (Q. kelloggii),
- Oregon Oak (Q. garryana)
- Big leaf maple (Acer macrophyllum).
- Further inland on north facing slopes or protected canyons these forests are dryer and lack Tanoak, Douglas Fir, and Coast Redwood but hold the rest of the species mentioned sometimes joined in with, and which also exist in the even dryer oak woodlandCalifornia oak woodlandCalifornia oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
s:- Coulter PineCoulter PineThe Coulter Pine or Big-cone Pine is a native of the coastal mountains of southern California and northern Baja California . Isolated groves are found as far north as the San Francisco Bay Area in Mt. Diablo State Park and Black Diamond Mines Regional Preserve...
(Pinus coulteri) or - Digger Pine (Pinus sabiniana)
- Coulter Pine
Common wildlife include Stellar's jay, Chestnut-backed Chickadee
Chestnut-backed Chickadee
The Chestnut-backed Chickadee is a small passerine bird in the tit family, Paridae....
, Western Gray Squirrel
Western Gray Squirrel
The Western Gray Squirrel is an arboreal rodent found along the western coast of the United States and Canada.In some places, this species has also been known as the Silver-gray Squirrel, the California Gray Squirrel, the Oregon Gray Squirrel, the Columbian Gray Squirrel and the Banner-tail...
, Raccoon
Raccoon
Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...
and many others. These forests are more diverse in animal life than those having only conifers due to the dominance of broadleaf trees thus offering more food sources. These forests offer a feel of broadleaf decidious forests only they are mostly evergreen.
Southern Coast, Transverse, and Peninsular Ranges mixed evergreen forest
Also called Southern mixed evergreen forests, the mixed evergreen forests of the southern California Coast Ranges, the Transverse RangesTransverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region that runs along the Pacific coast from Alaska to Mexico in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie between...
, and the northern Peninsular Ranges
Peninsular Ranges
The Peninsular Ranges are a group of mountain ranges, in the Pacific Coast Ranges, which stretch from southern California in the United States to the southern tip of Mexico's Baja California peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska...
, are restricted to cooler north-facing slopes at higher elevations.
- Predominant tree species include:
- Tanoak (Lithocarpus densiflorus)TanoakTanoak, formerly known taxonomically as Lithocarpus densiflorus, was recently moved into a new genus, Notholithocarpus, based on multiple lines of evidence....
- Madrone (Arbutus menziesii)
- Canyon Live Oak (Quercus chrysolepis)
- Coast Live Oak (Quercus agrifolia)Coast Live OakQuercus agrifolia, the Coast Live Oak, is an evergreen oak , native to the California Floristic Province. It grows west of the Sierra Nevada from Mendocino County, California, south to northern Baja California in Mexico. It is classified in the red oak section Quercus agrifolia, the Coast Live Oak,...
- California Bay Laurel (Umbellularia californica)
- Jeffrey Pine (Pinus jeffreyi)Jeffrey PineThe Jeffrey Pine, Pinus jeffreyi, named in honor of its botanist documenter John Jeffrey, is a North American pine related to Ponderosa Pine.-Distribution and habitat:...
- Coulter Pine (Pinus coulteri)Coulter PineThe Coulter Pine or Big-cone Pine is a native of the coastal mountains of southern California and northern Baja California . Isolated groves are found as far north as the San Francisco Bay Area in Mt. Diablo State Park and Black Diamond Mines Regional Preserve...
- Bigcone Douglas-fir (Pseudotsuga macrocarpa).
- Tanoak (Lithocarpus densiflorus)