This is a forest of angiosperms, the
flowering plants. We find fruit trees and berry bushes growing
wild here, along with insects to pollinate them. Although these
forests may go through mixed stands with conifers, the conifers
gradually disappear as changes in rainfall and climate favor
deciduous trees.
The deciduous forest supports
a diverse ecology. A warm growing season with abundant moisture
encourages plants to grow, and the ground is covered with small
plants, flowers, ferns, and grasses. In spring the trees and
shrubs produce new leaves and colorful flowers. In summer the
tall trees cast shade on the forest floor, providing ideal growing
conditions for shade-tolerant plants. Seeds and berries provide
for plant reproduction, and feed small rodents and birds. The
leaves that fall in the autumn provide plenty of material for
decomposers, soil bacteria, worms, grubs, and fungi. All these
plants together are the primary producers.
There are occasional open
areas where there is grass and sunshine, and streams thread their
ways down the mountains, providing microclimates for newts, frogs,
and fishes.
The
primary consumers in this system include insects,
birds, rodents and deer. There are many different kinds of insects,
including caterpillars that eat the leaves and later turn into
butterflies or moths. Rodents such as squirrels, wood mice, and
ground squirrels eat plants and their seeds. Deer browse on the
shrubs, grasses, and the leaves on the lower limbs of trees.
Birds eat seeds and berries, and many eat insects as well.
The predators (secondary
consumers) include foxes and owls (who eat the rodents)
and birds, skunks and opposums, who eat insects. The woods ring
with the sound of woodpeckers hammering trees in search of grubs.
The top predator
(tertiary consumers), the cougar, preys on deer
and smaller animals.
Bears are
omnivores and eat anything organic that they can get. They eat
some grass, berries, and mushrooms, but also need some high energy
protein food such as small animals and carrion (dead animals).
This food chain
has four trophic levels:
primary producers (plants), primary consumers (herbivores), secondary
consumers, and a tertiary consumer, the cougar. Contrast this
with food webs in the tundra and the deserts. Notice that this biome produces 6000 Kilocalories
of plant tissue per square meter per year. It is productive and
supports many species of plants and animals, only a few of which
have been mentioned here.
The Deciduous Forest
A Deciduous Forest Energy
Pyramid
Return to Introduction
to Biomes
©
Elizabeth Anne Viau, 1999. This material may be used freely for
instructional purposes but not sold for a price beyond the cost
of reproduction. Please inform the author if you use it at eviau@earthlink.net
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