Animal adaptation in
the Tropical Forest
Because there are so many animals competing for food, many animals have
adapted by learning to eat a particular food eaten by no other animal.
Toucans have adapted by developing long, large bill. This adaptation
allows this bird to reach fruit on branches that are too small to support
the bird's weight. The bill also is used to cut the fruit from the tree.
The sloth uses a behavioral adaptation and camouflage to survive in
the rainforest. It moves very, very slowly and spends most of its time
hanging upside down from trees. Blue-green algae grows on its fur giving
the sloth a greenish color and making it more difficult for predators
to spot.
Plant adaptation in the Tropical Forest
Plant survival in a tropical rainforest depends on the plant's ability
to tolerate constant shade or to adapt strategies to reach sunlight.
Fungus is a good example of a plant that flourishes in warm, dark places
created by the forest canopy and understory.
Competition for sunlight by plants is sometimes deadly. The strangler
fig needs sunlight to grow and reproduce. Seeds falling to the ground
quickly die in the deep shade and infertile soil of the tropical rainforest.
So it has adapted. Its seeds are deposited on branches of host trees
by birds and small animals that have eaten the fruit of the strangler
fig. The seeds sprout and send a long root to the ground. This root
rapidly increases in diameter and successfully competes for the water
and nutrients in the soil. As the strangler fig matures, branches and
leaves grow upwards creating a canopy that blocks sunlight from the
host tree. Additional roots are sent out and wrap around the host tree,
forming a massive network of roots that strangle and eventually kill
the host.
Animal Adaptations in the Deciduous Forest
Migration and hibernation are two adaptations used by the animals in
this biome. While a wide variety of birds migrate, many of the mammals
hibernate during the cold winter months when food is in short supply.
Another behavioral adaptation some animals have adopted is food storage.
The nuts and seeds that are plentiful during the summer are gathered
by squirrels, chipmunks, and some jays, and are stored in the hollows
of trees for use during the winter months. Cold temperatures help prevent
the decomposition of the nuts and seeds.
Plant adaptations
In the spring, deciduous trees begin producing thin, broad, light-weight
leaves. This type of leaf structure easily captures the sunlight needed
for food production (photosynthesis). The broad leaves are great when
temperatures are warm and there is plenty of sunlight. However, when
temperatures are cold, the broad leaves expose too much surface area
to water loss and tissue damage. To help prevent this damage from occurring,
deciduous trees make internal and physical adaptations that are triggered
by changes in the climate.
Animal adaptations in the Taiga
Most animals migrate to warmer climates once the cold weather begins.
Some animals have adapted to life in the taiga by hibernating when temperatures
drop. Other animals have adapted to the extreme cold temperatures by
producing a layer of insulating feathers or fur to protect them from
the cold.
In some instances, the adaptation of a seasonal change in color of
feathers or fur protects the animal from its predators. The ermine,
a small mammal, is a good example of this adaptation. Its dark brown
summer coat changes to white in the winter. This adaptation helps the
ermine blend into its surroundings and makes it more difficult for the
ermine's predators to spot them.
Plant adaptations in the Taiga
Evergreens use a wide variety of physical adaptations. Some of these
adaptations include their shape, leaf type, root system, and color.
Their name, evergreen, describes an important adaptation. They are always--or
ever green. Because they don't drop their leaves when temperatures cool,
they don't have to regrow them in the spring.
Growing new leaves takes a lot of energy. Plants get their energy from
the soil and from the Sun. Soil is a source of nutrients. Sunlight is
necessary for photosynthesis to take place in the plant. The taiga soil
doesn't contain many nutrients, and the Sun usually remains low in the
sky. These two factors limit the amount of energy available to the tree.
By keeping their leaves, the evergreens are able to use that limited
energy for structural growth rather than producing leaves.
Although the taiga has moderately high precipitation, the ground freezes
during the winter months and plant roots are unable to get water. The
adaptation from broadleaf to narrow needle-like structures limits water
loss through transpiration. Evergreen needles do not contain very much
sap. This limits the risk of needle damage from freezing temperatures.
The needles do, however, contain a chemical that repels animals who
would eat the needles. The dark green color of the needles absorbs the
sunlight, and since the needles are always present, once temperature
start to get warm, photosynthesis quickly begins. The conical shape
of the evergreens allows the snow to slide off the branches rather than
pile up. If the snow can't pile up on the branches, there is less risk
of broken branches due to the weight of the snow.
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