The
Pacific temperate rain forests ecoregion of
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
is the largest
temperate rain forestTemperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive high rainfall.-Definition:For temperate rain forests of North America, Alaback's definition is widely recognized:...
ecoregion on the planet as defined by the World Wildlife Fund (other definitions exist). The Pacific temperate rain forests lie along the western side of the
Pacific Coast RangesThe Pacific Coast Ranges or 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...
along the
Pacific NorthwestThe Pacific Northwest is a region in the northwest of North America, bound by the Pacific Ocean to the west. There are several partially overlapping definitions of the region, but they generally include the Canadian province of British Columbia and the U.S. states of Washington and Oregon, and...
Coast of
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
from
Kodiak IslandKodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...
in
AlaskaAlaska is the largest state of the United States of America by area; it is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
through the
British Columbia CoastThe British Columbia Coast or BC Coast is Canada's western continental coastline on the Pacific Ocean. The usage is synonymous with the term West Coast of Canada....
to
Northern CaliforniaNorthern California is the northern portion of the U.S. state of California. The region contains the San Francisco Bay Area, San Jose , Sacramento , as well as the substantial natural beauty of the redwood forests, the northern California coast, the Big Sur coastline area, the Sierra Nevada...
, and are part of the Nearctic ecozone, as also defined by the World Wildlife Fund. The Pacific temperate rain forests are characterized by a high amount of rainfall, in some areas more than 300 cm (120 inches) per year and moderate temperatures in both the summer and winter months (between 10-24°C).
These rain forests occur in a number of
ecoregionAn ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area smaller than a "realm" or "ecozone". Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species...
s, which vary in their species composition, but are predominantly of conifers, sometimes with an understory of broadleaf trees and
shrubA shrub or bush is a horticultural rather than strictly botanical category of woody plant, distinguished from a tree by its multiple stems and lower height, usually less than 5-6 m tall. A large number of plants can be either shrubs or trees, depending on the growing conditions they experience...
s. In the WWF's system, sub-ecoregions of the Pacific Temperate Rain Forests Ecoregion are the Northern Pacific coastal forests,
Queen Charlotte IslandsThe Queen Charlotte Islands or Haida Gwaii , and originally in Haida, Xhaaidlagha Gwaayaai , are an archipelago on the British Columbia Coast, Canada...
, British Columbia mainland coastal forests, Central Pacific coastal forests, Central and Southern Cascades forests, Klamath-Siskiyou forests, and Northern California coastal forests ecoregions.
The forests in the north contain predominantly
Sitka SpruceThe Sitka Spruce is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 100 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter. It is by far the largest species of spruce, and the third tallest conifer species in the world...
and
Western HemlockTsuga heterophylla 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 County, California....
, while those in the coastal forests are home as well to
Coast RedwoodSequoia sempervirens is the sole living species of the genus Sequoia in the cypress family Cupressaceae . Common names include Coast Redwood and California Redwood...
(Sequoia sempervirens),
Coast Douglas-firThe Coast Douglas-fir , a variety of Douglas-fir, is an evergreen conifer native to the coastal regions of western North America, from west-central British Columbia, Canada southward to central California, United States. In Oregon and Washington its range is continuous from the Cascades crest west...
(Pseudotsuga menziesii), Western Redcedar and Shore Pine. Notably, the three tallest species of trees are found here. Dense growths of
epiphyteAn epiphyte is:Epiphyte is one of the subdivisions of the Raunkiær system. The term most commonly refers to higher plants, but epiphytic bacteria, fungi , algae, lichens, mosses, and ferns exist as well. The term epiphytic derives from the Greek epi- and phyton...
s and
mossMosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
es cover the trees, and lush vegetation is present everywhere.
History
About 200 million years ago (during the
TriassicThe Triassic is a geologic period and system that extends from about 251 to 199 Ma . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
and
JurassicThe Jurassic is a geologic period and system that extends from about Ma to Ma, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the "Age of Reptiles". The start of the period is marked by...
periods), the landscape was dominated by
conifersThe conifers, division Pinophyta, also known as division Coniferophyta or Coniferae, are one of 13 or 14 division level taxa within the Kingdom Plantae. Pinophytes are gymnosperms. They are cone-bearing seed plants with vascular tissue; all extant conifers are woody plants, the great majority...
, which were the most diverse group of trees and constituted the greatest majority of large trees. When flowering plants emerged (in the following
CretaceousThe Cretaceous , Latin language for "chalky", usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago . In the geologic timescale, the Cretaceous follows on the Jurassic period and is followed by the Paleogene period of the...
period), they quickly prevailed, causing most conifers to become extinct, and those that survived to adapt to harsh conditions. Perhaps the most significant difference in this change is that the primitive conifers invested their energy in the basic food supply for every seed, with no certainty of fertilization; by contrast, flowering plants create the food supply for a seed only after it is triggered by fertilization. The Pacific temperate rain forest now remains the only region on Earth of noteworthy size and significance where, due to unique climatic conditions, the conifers flourish as they did before being displaced by flowering plants (Davis 2000).
The northern Pacific temperate rain forests are relatively young, emerging in the past few thousand years following the retreat of the
ice sheetAn ice sheet is a mass of glacier ice that covers surrounding terrain and is greater than 50,000 km² . The only current ice sheets are in Antarctica and Greenland; during the last glacial period at Last Glacial Maximum the Laurentide ice sheet covered much of Canada and North America, the...
s of the last
ice ageThe general term "ice age" or, more precisely, "glacial age" denotes a geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in an expansion of continental ice sheets, polar ice sheets and alpine glaciers. Within a long-term ice age, individual...
(Davis 2000).
Ecology
The ecosystem of Pacific temperate rain forests is so productive that the
biomassBiomass, a renewable energy source, is biological material derived from living, or recently living organisms, such as wood, waste, and alcohol fuels. Biomass is commonly plant matter grown to generate electricity or produce heat. For example, forest residues , yard clippings and wood chips may be...
in the best sites is at least four times greater than that of any comparable area in the
tropicsA tropical rainforest is an ecosystem usually found around the equator. They are common in Asia, Australia, Africa, South America, Central America, Mexico and on many of the Pacific Islands...
(Davis 2000). In sheer mass of living and decaying material - trees, mosses, shrubs, and soil - these forests are more massive than any other ecosystem on the planet. In part, this is due to the rarity of fire. Unlike drier forests, which burn periodically, temperate rain forests are naturally subject to only small-scale disturbances, such as blow-downs and avalanches.
This rain forest spans a wide range of latitude - from about
40 degrees northThe 40th parallel north is a circle of latitude that is 40 degrees north of the Earth's equatorial plane.Starting at the Prime Meridian and heading eastwards, the parallel 40° north passes through:-United States:...
to about
60 degrees northThe 60th parallel north is a circle of latitude that is 60 degrees north of the Earth's equatorial plane.Starting at the Prime Meridian and heading eastwards, the parallel 60° north passes through:-Canada:...
. The differences in climate from south to north create several major forest zones, characterized by different species.
- At the southern limit in northern California is the "coast redwood zone".
- Beginning at the California/Oregon border, and extending through the north end of Vancouver Island is the "seasonal rain forest zone". The major tree species here are Douglas fir, Western Red Cedar, Sitka spruce
The Sitka Spruce is a large coniferous evergreen tree growing to 50–70 m tall, exceptionally to 100 m tall, and with a trunk diameter of up to 5 m, exceptionally to 6–7 m diameter. It is by far the largest species of spruce, and the third tallest conifer species in the world...
, and Western HemlockTsuga heterophylla 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 County, California....
.
- Beyond the northern end of Vancouver Island, is the "perhumid rain forest zone". Douglas fir wanes as a dominant species, and the forest is primarily made up of western red cedar, Sitka spruce, and western hemlock.
- The Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
begins where the fjords of southeast Alaska end, and marks the transition into "sub-polar rain forest". Here the forest occupies only a very narrow strip between the ocean and the icy alpine zone. The cedar trees no longer thrive in this harsher climate, and the dominant trees are limited to Sitka spruce, and western and mountain hemlock.
- The northern limits of the rain forest are scattered in thin bands in the Kenai Fjords
Kenai Fjords National Park is a United States National Park established in 1980 by the Alaska National Interest Lands Conservation Act. The park covers an area of approximately 1,760 mi
2 on the Kenai Peninsula in southcentral Alaska, near the town of Seward. The park contains the...
, eastern Kodiak IslandKodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...
, and western Cook InletCook Inlet stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage....
.
Wildlife
The first survey to systematically explore the
forest canopyIn biology, the canopy is the aboveground portion of a plant community or crop, formed by plant crowns.For forests, canopy also refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms .Sometimes the term canopy is used to refer to the extent...
in the Carmanah Valley of
Vancouver IslandVancouver Island is a large island in British Columbia, Canada, one of several North American regions named after George Vancouver, the British Royal Navy officer who explored the Pacific coast of North America between 1791 and 1794....
yielded 15,000 new species, a third of all invertebrates known to exist in all of
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
. Among the collection were 500 species previously unknown to science (Davis 2000).
The rain forest exists in a complicated landscape of islands and fjords, and many species depend on both the forest and the ocean.
SalmonSalmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often attributed to the migratory life of the salmon as compared to the residential behaviour of trout, a distinction that holds true for the Salmo...
are one of the primary species of the rainforest, spawning in the forest streams. The
marbled murreletThe Marbled Murrelet is a small seabird from the North Pacific. It is a member of the auk family. It nests in old-growth forests or on the ground at higher latitudes where trees cannot grow...
nests in old growth trees at night, but feeds in the ocean during the day.
Many of the most iconic photos of these forests include a large bear somewhere in the frame. Grizzly bears and
black bearsThe American Black Bear also known as the North American black bear is the most common bear species native to North America. It lives throughout much of the continent, from northern Alaska south into Mexico and from the Atlantic Ocean to the Pacific Ocean. This includes 41 of the 50 U.S...
once thrived throughout the rain forest zone and beyond. Black bears can still be found throughout the forest's range, while grizzlies are largely confined to areas north of the Canadian border. These forests have some of the largest concentrations of grizzly bears in the world, mainly due to the region's rich salmon streams. The
Great Bear RainforestThe Great Bear Rainforest is the name given by environmental groups in the 1990s to a region of the temperate rain forest ecoregion specifically Pacific temperate rain forest ecoregion, located on the coast of British Columbia, Canada, from Vancouver Island north to the border with the US state of...
in Canada is home to the rare white variant of the black bear known as the "spirit bear". The endangered
spotted owlThe Spotted Owl, Strix occidentalis, is a species of true owl. It is a resident species of forests in western North America, where it nests in tree holes, old bird of prey nests, or rock crevices. Nests can be between 13 and 66 yards high and usually contain two eggs...
was at the center of logging controversies in Oregon and Washington. Other wildlife species of note include the
bald eagleThe Bald Eagle is a bird of prey found in North America that is most recognizable as the national bird and symbol of the United States of America. This sea eagle has two known sub-species and forms a species pair with the White-tailed Eagle. Its range includes most of Canada and Alaska, all of the...
,
marbled murreletThe Marbled Murrelet is a small seabird from the North Pacific. It is a member of the auk family. It nests in old-growth forests or on the ground at higher latitudes where trees cannot grow...
, wolf, and
sitka deerThe Sitka Deer or Sitka Black-tailed Deer , is a subspecies of Mule Deer , and similar to another subspecies the Black-tailed Deer . Their name originates from Sitka, Alaska...
.
Logging
Pacific temperate rain forests have been subject to ongoing large-scale industrial
loggingLogging is the process in which certain trees are cut down for forest management and timber.In forestry the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard. In common usage...
since the end of the Second World War, cutting over half of their total area. In California, only 4% of the redwoods have been protected. In
OregonOregon 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
WashingtonWashington is a state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute. It was admitted to the Union as the...
, less than 10% of original coastal rain forest remains.
An even larger percentage of the productive forest has been logged. Much of the land is rock, ice, muskeg, or less productive forest on steep slopes. The stereotypical old growth is limited to lowland flats and valleys, which have been preferentially targeted for logging. Historically, the most common protocol has been to place protected areas in the mountains, leaving the valleys to the timber industry. So while some very large areas are protected as parks and monuments, very little of the highest-value habitat has been protected, and much of it has already been cut.
In the
Tongass National ForestAt 17 million acres , the Tongass National Forest in southeastern Alaska is the largest national forest in the United States...
, in the 1950s, in part to aid in Japanese recovery from WWII, the Forest Service set up long term contracts with two pulp mills: the Ketchikan Pulp Company and the Alaska Pulp Company. These contracts were for 50 years, and divided up the forest into areas slated for APC logs and areas slated for KPC logs. These two companies conspired to drive log prices down, conspired to drive smaller logging operations out of business, and were major and recalcitrant polluters of their local areas. These long term contracts guaranteed low prices to the pulp companies — in some cases resulting in trees being given away for less than the price of a hamburger. Since 1980, the forest service has lost over a billion dollars in Tongass timber sales.
Half a million acres (2,000 km²) of the Tongass was selected by native corporations under the 1971
Alaska Native Claims Settlement ActThe Alaska Native Claims Settlement Act, commonly abbreviated ANCSA, was signed into law by President Richard M. Nixon on December 18, 1971, the largest land claims settlement in United States history. ANCSA was intended to resolve the long-standing issues surrounding aboriginal land claims in...
. Most of this area has been clearcut.
The most controversial timber sales in the Tongass are in the roadless areas. In September 2006, a landmark court decision overturned Bush's repeal of the Roadless Rule, reverting to the 2001 roadless area protections established under Clinton. However, the Tongass was exempted from that ruling, and it is unclear what the fate of its vast roadless areas will be.
See also
- Great Bear Rainforest
The Great Bear Rainforest is the name given by environmental groups in the 1990s to a region of the temperate rain forest ecoregion specifically Pacific temperate rain forest ecoregion, located on the coast of British Columbia, Canada, from Vancouver Island north to the border with the US state of...
- Pacific Northwest
The Pacific Northwest is a region in the northwest of North America, bound by the Pacific Ocean to the west. There are several partially overlapping definitions of the region, but they generally include the Canadian province of British Columbia and the U.S. states of Washington and Oregon, and...
- Temperate rain forest
Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive high rainfall.-Definition:For temperate rain forests of North America, Alaback's definition is widely recognized:...
- Tongass National Forest
At 17 million acres , the Tongass National Forest in southeastern Alaska is the largest national forest in the United States...
- Olympic National Park
Olympic National Park is located in the U.S. state of Washington, in the Olympic Peninsula. The park can be divided into three basic regions: the Pacific coastline, the Olympic Mountains, and the temperate rainforest. U.S...
External links