The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface.
The Pacific Coast Ranges are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although they are commonly thought to be the westernmost mountain range of the continental United States and Canada, the geologically distinct Insular Mountains of Vancouver Island lie farther west.
The Klamath Mountains are a rugged and lightly-populated mountain range in northwestern California and southwestern Oregon in the western United States. As a mountain system within both the greater Pacific Coast Ranges and the California Coast Ranges, the Klamath Mountains have a varied geology, with substantial areas of serpentinite and marble, and a climate characterized by moderately cold winters with very heavy snowfall and warm, very dry summers with limited rainfall, especially in the south. As a consequence of the geology and soil types, the mountains harbor several endemic or near-endemic trees, forming one of the largest collections of conifers in the world. The mountains are also home to a diverse array of fish and animal species, including black bears, large cats, owls, eagles, and several species of Pacific salmon. Millions of acres in the mountains are managed by the United States Forest Service. The northernmost and largest sub-range of the Klamath Mountains are the Siskiyou Mountains.
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 California. It is named in honor of its botanist documenter John Jeffrey.
The California chaparral and woodlands is a terrestrial ecoregion of southwestern Oregon, northern, central, and southern California and northwestern Baja California (Mexico), located on the west coast of North America. It is an ecoregion of the Mediterranean forests, woodlands, and scrub biome, and part of the Nearctic realm.
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 most widely distributed pine species in North America.
The ecology of California can be understood by dividing the state into a number of ecoregions, which contain distinct ecological communities of plants and animals in a contiguous region. The ecoregions of California can be grouped into four major groups: desert ecoregions, Mediterranean ecoregions, forested mountains, and coastal forests.
The Northern California coastal forests are a temperate coniferous forests ecoregion of coastal Northern California and southwestern Oregon.
Plumas National Forest is a 1,146,000-acre (4,640 km2) United States National Forest located at the northern terminus of the Sierra Nevada, in northern California. The Forest was named after its primary watershed, the Rio de las Plumas, or Feather River.
California mixed evergreen forest is a plant community found in the mountain ranges of California and southwestern Oregon.
The Coast Ranges of California span 400 miles (644 km) from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains.
The California Floristic Province (CFP) is a floristic province with a Mediterranean-type climate located on the Pacific Coast of North America with a distinctive flora similar to other regions with a winter rainfall and summer drought climate like the Mediterranean Basin. This biodiversity hotspot is known for being the home of the Sierran giant sequoia tree and its close relative the coast redwood. In 1996, the Province was designated as a biodiversity hotspot allowing it to join ranks among 33 other areas in the world with many endemic species. To be named a biodiversity hotspot, an area has to contain species and plant life that cannot be found anywhere else in the world. The California Floristic Province is home to over 3,000 species of vascular plants, 60% of which are endemic to the province.
North American Atlantic Region is a floristic region within the Holarctic Kingdom identified by Armen Takhtajan and Robert F. Thorne, spanning from the Atlantic and Gulf coasts to the Great Plains and comprising a major part of the United States and southeastern portions of Canada. It is bordered by the Circumboreal floristic region in the north, by the Rocky Mountain and Madrean floristic regions in the west and by the Caribbean floristic region of the Neotropical Kingdom in the south of Florida. The flora of the region comprises two endemic monotypic families, Hydrastidaceae and Leitneriaceae, and is characterized by about a hundred of endemic genera. The degree of species endemism is very high, many species are Tertiary relicts, which survived the Wisconsin glaciation and are now concentrated in the Appalachians and the Ozarks. A number of genera are shared only with the Canadian floristic province of the Circumboreal region. Moreover, as has long been noted, a large number of relict genera are shared with the relatively distant Eastern Asiatic Region and sometimes Southeast Asia. R. F. Thorne counted at least 74 genera restricted to eastern North America and Asia. The fossil record indicates that during the Tertiary period a warm temperate zone extended across much of the Northern Hemisphere, linking America to Asia.
The native flora of the United States includes about 17,000 species of vascular plants, plus tens of thousands of additional species of other plants and plant-like organisms such as algae, lichens and other fungi, and mosses. About 3,800 additional non-native species of vascular plants are recorded as established outside of cultivation in the U.S., as well as a much smaller number of non-native non-vascular plants and plant relatives. The United States possesses one of the most diverse temperate floras in the world, comparable only to that of China.
The Madrean Region is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne. It occupies arid or semiarid areas in the southwestern United States and northwestern Mexico and is bordered by the Rocky Mountain Floristic Region and North American Atlantic Region of the Holarctic Kingdom in the north and in the east, Caribbean Region of the Neotropical Kingdom in the south.
The Circumboreal Region in phytogeography is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan.
The Klamath Mountains ecoregion of Oregon and California lies inland and north of the Coast Range ecoregion, extending from the Umpqua River in the north to the Sacramento Valley in the south. It encompasses the highly dissected ridges, foothills, and valleys of the Klamath and Siskiyou Mountains. It corresponds to the Level III ecoregion designated by the Environmental Protection Agency and to the Klamath-Siskiyou forests ecoregion designated by the World Wide Fund for Nature.
Ceanothus prostratus is a species of shrub in the family Rhamnaceae. Common names include prostrate ceanothus, pinemat, and mahala mat. It is native to the Pacific Northwest of the United States where it grows in coniferous forests and open plateaus.
Mixed coniferous forest is a vegetation type dominated by a mixture of broadleaf trees and conifers. It is generally located in mountains, below the upper montane vegetation type.
