The Klamath Mountains ecoregion of

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

and

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

lies inland and north of the Coast Range ecoregion, extending from the

Umpqua River The Umpqua River ( ) on the Pacific coast of Oregon in the United States is approximately long. One of the principal rivers of the Oregon Coast and known for bass and shad, the river drains an expansive network of valleys in the mountains west ...

in the north to the

Sacramento Valley , photo =Sacramento Riverfront.jpg , photo_caption= Sacramento , map_image=Map california central valley.jpg , map_caption= The Central Valley of California , location = California, United States , coordinates = , boundaries = Sierra Nevada (ea ...

in the south. It encompasses the highly dissected

ridge A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...

foothill Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topograp ...

s, and

valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...

s of the Klamath and

Siskiyou Mountains The Siskiyou Mountains are a coastal subrange of the Klamath Mountains, and located in northwestern California and southwestern Oregon in the United States. They extend in an arc for approximately from east of Crescent City, California, nort ...

. It corresponds to the Level III ecoregion designated by the

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale ...

and to the Klamath-Siskiyou forests ecoregion designated by the

World Wide Fund for Nature The World Wide Fund for Nature Inc. (WWF) is an international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the W ...

. The

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

, also known as a ''geomorphic province,'' was

unglaciated A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

during the

Pleistocene epoch The Pleistocene ( , often referred to as the '' Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed i ...

, when it served as a refuge for northern plant species. Its mix of granitic,

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

, and

extrusive Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff. In contra ...

rocks contrasts with the predominantly

volcanic rock Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic ...

s of the Cascades ecoregion to the northeast. The mild, subhumid

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...

of the region is characterized by a lengthy summer

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

. It supports a mosaic of both northern Californian and

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Thou ...

ern

conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

s and

hardwood Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from ...

Ecology

The ecoregion harbors rich

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic ('' genetic variability''), species ('' species diversity''), and ecosystem ('' ecosystem diversity'') ...

, with several distinct plant communities, including

temperate rain forest Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American P ...

s, moist inland forests, oak forests and savannas, high elevation forests, and alpine grasslands. Thirty

species inhabit the region, including seven

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

species, making the region one of the richest coniferous forest regions of the world in species diversity. The region also has several edaphic plant communities (adapted to specific soil types), notably those of the region's serpentine outcrops.

Conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

species include Coast Douglas-fir ''(Pseudotsuga menziesii'' subsp. ''menziesii)'',

Lawson's Cypress ''Chamaecyparis lawsoniana'', known as Port Orford cedar or Lawson cypress, is a species of conifer in the genus '' Chamaecyparis'', family Cupressaceae. It is native to Oregon and northwestern California, and grows from sea level up to in the ...

(also known as Port Orford Cedar, ''Chamaecyparis lawsoniana''),

Ponderosa Pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

''(Pinus ponderosa)'',

Sugar Pine ''Pinus lambertiana'' (commonly known as the sugar pine or sugar cone pine) is the tallest and most massive pine tree, and has the longest cones of any conifer. The species name ''lambertiana'' was given by the Scottish botanist David Douglas, ...

''(Pinus lambertiana)'', Mountain Hemlock ''(Tsuga mertensiana)'', White Fir ''(Abies concolor'' subsp. ''lowiana)'', Red Fir ''(A. magnifica'' subsp. ''shastensis)'', Weeping Spruce ''(Picea breweriana)'',

Coast Redwood ''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal ...

''(Sequoia sempervirens)'', and

Pacific Yew ''Taxus brevifolia'', the Pacific yew or western yew, is a species of tree in the yew family Taxaceae native to the Pacific Northwest of North America. It is a small evergreen conifer, thriving in moisture and otherwise tending to take the form ...

''(Taxus brevifolia)''. These forests mark the northern extent of the range for California Buckeye.

Level IV ecoregions

The Oregon portion of the ecoregion has been subdivided into seven Level IV ecoregions, as described below.

Rogue/Illinois Valleys (78a)

The Rogue/Illinois Valleys ecoregion includes terraces and

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s in the

Rogue A rogue is a person or entity that flouts accepted norms of behavior. Rogue or rogues may also refer to: Companies * Rogue Ales, a microbrewery in Newport, Oregon * Rogue Arts, a film production company * Rogue Entertainment, a software co ...

and

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rock ...

river valleys at an elevation of 900 to 2,000 feet (274 to 610 m). Historically, the valleys supported Oregon white oak and

California black oak ''Quercus kelloggii'', the California black oak, also known as Kellogg oak, is an oak in the red oak section (genus ''Quercus'', section ''Lobatae'', series ''Agrifoliae''), native to western North America. Although genetically separated from the ...

woodland, with

Pacific madrone ''Arbutus menziesii'' or Pacific madrone (commonly madrone or madrona in the United States and arbutus in Canada), is a species of broadleaf evergreen tree in the family Ericaceae, native to the western coastal areas of North America, from Br ...

ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

, and

grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...

. Common

understory In forestry and ecology, understory (American English), or understorey (Commonwealth English), also known as underbrush or undergrowth, includes plant life growing beneath the forest canopy without penetrating it to any great extent, but abo ...

plants included California fescue,

snowberry ''Symphoricarpos'', commonly known as the snowberry, waxberry, or ghostberry, is a small genus of about 15 species of deciduous shrubs in the honeysuckle family, Caprifoliaceae. With the exception of the Chinese coralberry, '' S. sinensis'', whi ...

, and

serviceberry ''Amelanchier'' ( ), also known as shadbush, shadwood or shadblow, serviceberry or sarvisberry (or just sarvis), juneberry, saskatoon, sugarplum, wild-plum or chuckley pear,A Digital Flora of Newfoundland and Labrador Vascular Plants/ref> is a g ...

. Riparian areas supported

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist so ...

and cottonwood. Much of the land has been developed for

agricultural Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peopl ...

residential A residential area is a land used in which housing predominates, as opposed to industrial and commercial areas. Housing may vary significantly between, and through, residential areas. These include single-family housing, multi-family resi ...

use, and little of the original

vegetation Vegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic charac ...

remains. Remnants of

oak savanna An oak savanna is a type of savanna—or lightly forested grassland—where oaks (''Quercus ''spp.) are the dominant trees. The terms "oakery" or "woodlands" are also used commonly, though the former is more prevalent when referencing the Medite ...

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

vegetation, and seasonal

pond A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from tha ...

s persist on the

mesa A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a ...

tops of the Table Rocks north of Medford. Elsewhere, land uses include

orchard An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit- or nut-producing trees which are generally grown for commercial production. Orchards are also sometimes a feature of ...

cropland Agricultural land is typically land ''devoted to'' agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with bot ...

, and

pastureland Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or ...

. Climate, vegetation, and resulting land use are more similar to

Northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

’s inland valleys than to the Willamette Valley ecoregion to the north. The region covers in Oregon, in three separate areas around Medford and Ashland,

Grants Pass Grants Pass is the county seat of Josephine County, Oregon, United States. The city is located on Interstate 5 in Oregon, Interstate 5, northwest of Medford, Oregon, Medford, along the Rogue River (Oregon), Rogue River. The population was 39,189 ...

, and

Cave Junction Cave Junction is a city in Josephine County, Oregon, United States. As of the 2020 census, the city population was 1,995. Its motto is the "Gateway to the Oregon Caves", and the city got its name by virtue of its location at the junction of Redw ...

Oak Savanna Foothills (78b)

The Oak Savanna Foothills ecoregion consists of moderately sloping mountain foothills bordering the Rogue and Illinois river valleys and sharing their

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

. Elevation varies from 1,400 to 4,000 feet (427 to 1,219 m). The driest area, east of Medford, is dominated by Oregon white oak and California black oak woodlands, grassland-savanna, ponderosa pine, and Coast Douglas-fir. The wetter foothills flanking the Illinois Valley support Douglas-fir, madrone, and California incense-cedar. Understory species include oceanspray,

Western poison-oak ''Toxicodendron diversilobum'' (syn. ''Rhus diversiloba''), commonly named Pacific poison oak or western poison oak, is a woody vine or shrub in the sumac family, Anacardiaceae. It is widely distributed in western North America, inhabiting coni ...

, snowberry, Idaho fescue, California brome, roughstalk bluegrass, and

ceanothus ''Ceanothus'' is a genus of about 50–60 species of nitrogen-fixing shrubs and small trees in the buckthorn family ( Rhamnaceae). Common names for members of this genus are buckbrush, California lilac, soap bush, or just ceanothus. ''"Ceanothu ...

. The region is lower and less dissected, with more oak woodland and less closed-canopied forest than the Inland Siskiyous. It covers in Oregon.

Umpqua Interior Foothills (78c)

The Umpqua Interior Foothills ecoregion is a complex of foothills and narrow valleys containing fluvial terraces and floodplains. Elevation varies from 400 to 2,800 feet (122 to 853 m). It is drier than the foothills of the Willamette Valley, partly because the summer Pacific high pressure system arrives earlier and remains longer than in ecoregions to the north. Summers are hot and dry, and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

s have a

xeric moisture regime Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this h ...

in contrast to the udic soils of the Mid-Coastal Sedimentary ecoregion to the west. The slopes are covered by Oregon white oak woodland, Douglas-fir, grand fir, ponderosa pine, madrone, tanoak, and chinkapin, with an understory

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranea ...

community that includes snowberry,

salal ''Gaultheria shallon'' is an evergreen shrub in the heather family (Ericaceae), native to western North America. In English, it is known as salal, shallon, or (mainly in Britain) gaultheria. Description ''Gaultheria shallon'' is tall, spra ...

, Oregon grape, poison oak, oceanspray, and swordfern. Many areas have been converted to pastureland,

vineyard A vineyard (; also ) is a plantation of grape-bearing vines, grown mainly for winemaking, but also raisins, table grapes and non-alcoholic grape juice. The science, practice and study of vineyard production is known as viticulture. Vineyard ...

s, orchards, and

row crop A row crop is a crop that can be planted in rows wide enough to allow it to be tilled or otherwise cultivated by agricultural machinery, machinery tailored for the seasonal activities of row crops. Such crops are sown by drilling or transplantin ...

s. It covers in Oregon in the Umpqua Valley, including the city of Roseburg. Arabis aculeolata 4640

Serpentine Siskiyous (78d)

The Serpentine Siskiyous ecoregion consists of highly dissected

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...

s containing perennial, high gradient

stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ...

s at an elevation of 1,500 to 4,300 feet (457 to 1,311 m). It is lithogically distinct from the rest of the Klamath Mountains ecoregion. Many plants have difficulty growing in its

serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially anti ...

s due to a shortage of

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

and high levels of

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow t ...

, and

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hard ...

. As a result, vegetation is often sparse and composed of specialist species that have evolved to grow in the potentially toxic and nutrient-poor serpentine soils. It supports a mixed conifer forest of

Jeffrey pine ''Pinus jeffreyi'', also known as Jeffrey pine, Jeffrey's pine, yellow pine and black pine, is a North American pine tree. It is mainly found in California, but also in the westernmost part of Nevada, southwestern Oregon, and northern Baja Califo ...

, tanoak, incense-cedar, Douglas-fir, and

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial ...

chaparral composed of manzanita,

, Idaho fescue, and Lemmon needlegrass. Historic

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile ...

, nickel,

chromite Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of FeCr2O4. It is an oxide mineral belonging to the spinel group. The element magnesium can ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pink ...

, and mercury

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the econom ...

have contributed to

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

problems. The region covers in Oregon, including portions of the Rogue River – Siskiyou National Forest and the

Kalmiopsis ''Kalmiopsis'' is a small genus of flowering plants in the family Ericaceae. Species It contains two species, which are endemic to Oregon in the United States.Wild Rogue wildernesses. Contiguous areas in California have not been mapped yet.

Inland Siskiyous (78e)

The Inland Siskiyous ecoregion is higher and more mountainous than the neighboring foothill and valley ecoregions, with an elevation of 800 to 7,000 feet (244 to 2,134 m). It has a higher

fire Fire is the rapid oxidation of a material (the fuel) in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. At a certain point in the combustion reaction, called the ignition point, flames ...

frequency, less annual

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

, and longer summer droughts than the Coastal Siskiyous. Forest cover is a diverse and multi-layered mix of conifers,

broadleaf evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

s, and

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

trees and shrubs, featuring Douglas-fir, ponderosa pine, Oregon white oak, California black oak, madrone, serviceberry, snowberry, Oregon grape, California fescue, and poison oak. The largest of the Klamath Mountains subregions mapped so far, it covers in Oregon, including public lands within the Rogue River – Siskiyou National Forest. Contiguous areas in California have not been mapped yet.

Coastal Siskiyous (78f)

The Coastal Siskiyous ecoregion consists of highly dissected mountains with a wetter and milder

maritime climate An oceanic climate, also known as a marine climate, is the humid temperate climate sub-type in Köppen classification ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters ...

than elsewhere in the Klamath Mountains ecoregion. Elevation varies from 600 to 5,300 feet (183 to 1,615 m). Productive forests composed of tanoak, Douglas-fir, bigleaf maple, California laurel, and some

Port Orford cedar ''Chamaecyparis lawsoniana'', known as Port Orford cedar or Lawson cypress, is a species of conifer in the genus '' Chamaecyparis'', family Cupressaceae. It is native to Oregon and northwestern California, and grows from sea level up to in the ...

cover its mountainous landscape, with chinkapin, salal,

rhododendron ''Rhododendron'' (; from Ancient Greek ''rhódon'' "rose" and ''déndron'' "tree") is a very large genus of about 1,024 species of woody plants in the heath family (Ericaceae). They can be either evergreen or deciduous. Most species are nati ...

, and swordfern; tanoak is more common than elsewhere in Oregon.

Broadleaf evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

s, such as tanoak and madrone, quickly

colonize Colonization, or colonisation, constitutes large-scale population movements wherein migrants maintain strong links with their, or their ancestors', former country – by such links, gain advantage over other inhabitants of the territory. When ...

disturbed areas, making it difficult to regenerate conifer forest growth. Xeric soils derived from Siskiyou rock types are characteristic; udic soils which support

western hemlock ''Tsuga heterophylla'', the western hemlock or western hemlock-spruce, is a species of hemlock native to the west coast of North America, with its northwestern limit on the Kenai Peninsula, Alaska, and its southeastern limit in northern Sonoma ...

and

Sitka spruce ''Picea sitchensis'', the Sitka spruce, is a large, coniferous, evergreen tree growing to almost tall, with a trunk diameter at breast height that can exceed 5 m (16 ft). It is by far the largest species of spruce and the fifth-lar ...

are present but are less common than in the wetter Coast Range ecoregion to the west. The region covers in Oregon, including portions of the Rogue River – Siskiyou National Forest and the Kalmiopsis and Wild Rogue Wilderness wildernesses. Contiguous areas in California have not been mapped yet.

Klamath River Ridges (78g)

The Klamath River Ridges is characterized by highly dissected mountains, with a dry,

continental climate Continental climates often have a significant annual variation in temperature (warm summers and cold winters). They tend to occur in the middle latitudes (40 to 55 north), within large landmasses where prevailing winds blow overland bringing so ...

. Elevation varies from 3,800 to 7,500 feet (1,158 to 2,286 m). Vegetation varies with slope, aspect, and elevation. Higher altitudes and north-facing slopes have Douglas-fir and white fir; lower elevations and south-facing slopes are covered in

and

western juniper ''Juniperus occidentalis'', known as the western juniper, is a shrub or tree native to the Western United States, growing in mountains at altitudes of and rarely down to . It is listed as Least Concern on the IUCN Red List because it is a wides ...

, species that are more drought-resistant than other vegetation types found within the region. The chaparral features Oregon grape, western fescue, snowberry, bluebunch wheatgrass, and

. The region covers in Oregon near the Siskiyou Summit, including portions of the Rogue River – Siskiyou National Forest and the

Cascade–Siskiyou National Monument The Cascade–Siskiyou National Monument is a United States national monument that protects of forest and grasslands at the junction of the Cascade Range and the Siskiyou Mountains in Southwestern Oregon and Northwestern California, United Stat ...

. Contiguous areas in California have not been mapped yet.

References

External links

A Celebration of the Conifer Diversity in Northwest CaliforniaConifers of Northwest California
*CNPS
Rare and Endemic Conifers of Northwest California
{{DEFAULTSORT:Klamath Mountains (Epa Ecoregion) *Eco 1 01 K 01 Ecoregions of California Ecoregions of Oregon Pacific temperate rainforests

Ecology

Level IV ecoregions

Rogue/Illinois Valleys (78a)

Oak Savanna Foothills (78b)

Umpqua Interior Foothills (78c)

Serpentine Siskiyous (78d)

Inland Siskiyous (78e)

Coastal Siskiyous (78f)

Klamath River Ridges (78g)

See also

References

External links