Here is a place where the
very air seems green!
Notice the dark trunks of the evergreens,
the tallest trees in this ecosystem.
Notice the fragile shorter trees: these
are vine maples that grow in the shade of the evergreens.
The forest floor is covered by ferns, mosses,
and small plants. Mosses and lichens grow on the tree trunks
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:
The Sitka Spruce
The Western Red Cedar
The Western Hemlock
When these trees are full grown, they are between 130 to 280
In some areas other conifers dominate. For example, in California
redwood trees grow in the temperate rain forest.
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
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.
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
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