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Temperate rain forests are found on the western edge of North and South America, where moist air from the Pacific Ocean drops between 60 and 200 inches of rain a year. Unlike the tropical rain forest, the temporate rain forest has seasonal varition, with summer temperatures rising to about 80 degrees Fahrenheit and winter temperatures dropping to near freezing. In the northernmost regions, winter may be cold enough for some ice and snow. Although this rain forest has
layers of tall, medium, and low growing vegetation, the cool
winters limit the numbers and kinds of life forms that live here.
Compared to the tropical rain
forest, the temperate rain forest has a less complex ecology.
For example, the topmost layer of the temperate rain forest on
the western edge of North America is dominated by four kinds
of tall coniferous trees. These are:
Small shade-loving trees, such as dogwoods and vine maples, form the understory level. Beneath the trees, shrubs such as wild currants, thimbleberries, and huckleberries grow in the filtered sunlight. Sword ferns, salal, and Oregan grape plants also thrive here. At the ground level, the earth is littered with dead fir needles, leaves, twigs, and fallen trees. These lie on and under a thick carpet of mosses, lichens, grasses, and small plants, such as Oregon oxalis (which has leaves like a shamrock). The rocks are green with moss, and the tree trunks and branches are covered with moss and algae. These low-growing plants are shade tolerant. Here and there one may find toadstools, mushrooms, and other kinds of fungi: these saprophites (organisms that digest dead organic matter) help to recycle the dead material on the forest floor. Scientists say that there is more biomass in this biome than in any other biome on earth. There may be 500 tons of living things per acre here! That translates down to about 206 pounds per square yard, about the same as one good sized human adult per square yard! Most of the animals in this forest live on or near the ground, where there is lots of food, and the trees provide shelter from sun, wind, and rain. Beetles burrow in the moss and hide in the bark of trees. Wood peckers and birds eat the insects. Grass is eaten by the voles (cute little mouse-like animals) and the deer. There is food that is easier to eat than the tough needles of the conifers. However, the conifers do provide food when they make their nourishing seeds. Birds and small animals eat these seeds. Photos from Art Today. Copyrighted: not for downloading. Copyright © 2000. Elizabeth Anne Viau and her licensors. All rights reserved. This material may be used by individuals for instructional purposes but not sold. Please inform the author if you use it at eviau@earthlink.net |
This forest has nutrient-rich soil because there is a lot of
dead organic matter on the ground. This dead material is being
slowly digested by the fungi, insects, and bacteria that live
here. In the tropical forests the trees have to spend some of
their energy drawing up water and getting rid of heat: in this
milder climate the trees can grow and grow.