The world's largest temperate rain forests are found on the Pacific coast of North America. The forests start in Alaska and run along the coast to Oregon and California. Isolated patches of temperate rain forests are found in coastal Chile, Norway, the United Kingdom, Japan, Australia and New Zealand. The temperate rain-forest biome, or sets of related ecosystems, support many species of flora and fauna.
The defining special feature of the temperate rain forest is its climate. The mild weather conditions are maintained by moisture-laden air blown in off the Pacific Ocean and hemmed in by the coastal mountains. The forest can get from 60 to 200 inches of precipitation annually. Dense fog generated by the nearby sea helps water the forest and its plant life. The rain forest experiences seasonal temperature variations from 80 degrees Fahrenheit in summer to near freezing in the winter.
One of the most conspicuous special features of the temperate rain forests are the tall evergreen trees dominating the landscape. The coastal California redwood trees are the tallest in the world, reaching heights above 360 feet. The second most prominent tree is the Douglas fir, growing 280 feet tall. Mature specimens of cedar and spruce trees typically exceed 200 feet. The western hemlock is another tall conifer at 130 feet. The ancient old-growth forests produce a huge amount of biomass per acre.
Epiphytes constitute one of the most notable features of the temperate rain forest's flora. Epiphytes are mostly species of mosses and ferns that live on the branches and trunks of trees, especially the broad-leafed maples. The plants use the trees to reach the brighter sunlight near the forest's canopy. Many species of large ferns inhabit the shady forest floors. Sword and Bracken ferns' fronds may be 5 feet long. Thick deer ferns thrive on the moist, shadowy forest floor.
Wild salmon are one of the most distinctive members of the temperate rain forest's fauna. Six species inhabit the rain forest ecosystem: Chinook, sockeye, coho, pink, steelhead and chum. The fish turn bright red as they swarm from the ocean to swim upriver to their spawning grounds. Once there, they reproduce and die soon afterwards. The massive die-off provides a feast to the forest's black bears, lynx, wolves and other animals. The fish attempt to overcome all barriers as they return to the place of their birth to lay eggs.