The Temperate Rainforest Biome
The worldwide distribution of temperate rainforests is quite small. They are located primarily on the northwest coast of North America between northern California and southeastern Alaska, in New Zealand and Chile, and a small number of other locations. Temperate rainforests receive at least 200 cm (78 inches) of precipitation each year, and have a moderate temperature range that averages about 15 degrees C (60 degrees F). Since their climate is cooler, the biodiversity of temperate rainforests is less than that of tropical rainforests.
What are Consumers?
The food chain is composed of producers that make their own food by photosynthesis, such as plants, and consumers, which depend on other organisms for nourishment. Consumers are divided into three categories:
- Primary consumers are herbivores, animals that eat only plants. Primary consumers include insects, small mammals such as rabbits, and larger mammals such as deer and elk.
- Secondary consumers are one level up from primary consumers in the food chain. They may be omnivores that eat both plants and animals, or carnivores that eat only animals. The diet of secondary consumers includes primary consumers. Examples of secondary consumers are bears, snakes and foxes.
- Tertiary consumers are the carnivores at the top of the food chain in a given ecosystem. They eat only meat, and their diet usually includes secondary consumers. Examples of tertiary consumers are hawks and mountain lions.
Some Examples of Consumers in the Temperate Rainforest
Pacific Salmon– Salmon are unusual because they are anadromous, meaning they spend most of their lives in the salt water of the Pacific Ocean, but swim many miles upstream to the rivers or streams where they were born to spawn. After they hatch, young salmon return to the sea. Most species of salmon die after spawning. While they are in freshwater streams, salmon eat aquatic insects such as caddis flies and mayflies, plankton, crustaceans and terrestrial insects. Pacific salmon are a critical part of the temperate rainforest ecosystem, because they provide food for a large number of other species.
Black Bear– Black bears prefer to live in densely overgrown habitat that provides cover and plentiful food in the form of vegetation. Black bears are omnivores, feeding on various types of vegetation such as grass, shrubs, fruits and nuts, as well as fish and small animals. The rare White Spirit Bear, or Kermode, found only in the temperate rainforests of British Columbia, is a subspecies of the black bear.
Roosevelt Elk– Roosevelt elk are native to the temperate rainforests of the Pacific Northwest. They are the largest of the herbivores, the males weighing as much as 1,000 pounds. Their foraging and grazing helps to keep the forest floor from becoming overgrown. Elk eat lichens and many types of plants and shrubs including blackberry, huckleberry, salal and vine maple.
Mountain Lion– Mountain lions are carnivores that eat a wide range of other animals, from mice, squirrels and raccoons up to deer and moose. Mountain lions hunt by stalking and then leaping onto the back of their prey and breaking its neck by biting it with their powerful jaws.
Some other consumers of the temperate rainforest include beavers, raccoons, amphibians, banana slugs, small mammals such as mice, voles and weasels, and many species of birds including owls, hawks and eagles.