The picture shows a food web in a temperate deciduous forest.|
The Temperate Deciduous Forest biome has four seasons of winter, spring, summer and fall. Animals and plants have special adaptations to cope with these yearly changes.
Deciduous trees are trees that shed their leaves once a year at the approach of a cold or dry season and later grow new leaves. (Plants that keep their foliage throughout the year are called evergreens.) Deciduous trees usually have broad leaves e.g., ash, beech, birch, maple and oak.
- In SUMMER, their broad green leaves help capture sunlight needed to make food through photosynthesis.
- As temperatures drop, the tree cuts off the supply of water to the leaves and seals off the area between the leaf stem and the tree trunk. With limited sunlight and water, the leaves are unable to continue producing chlorophyll (green pigment in leaves) causing them to change into the beautiful red, yellow and orange leaf colours of FALL.
- In WINTER, it is too cold for the trees to protect their leaves from freezing, so they simply loose them and seal up the places where the leaves attach to the branch. Losing their leaves helps trees to conserve water loss through transpiration. (Dried leaves continue to hang on the branches of some deciduous trees until the new leaves come out.)
Before the leaves die, some of the food material they contain is drawn back into the twigs and branches where it is stored and used the following spring.
- The warmer temperatures of SPRING signal to the trees that they can grow new leaves again, and restart the cycle.
Animals in temperate deciduous forests also have to adapt to the changing seasons. They must be able to cope with cold winters when food is in short supply. Migration and hibernation are two adaptations used by the animals in this biome.
Squirrels, chipmunks, and some jays often store large supplies of food (such as nuts and seeds) in the ground, under fallen leaves, or in tree hollows for use during the cold winters when food is scarce. Cold temperatures help prevent the decomposition of the nuts and seeds.
- A great variety of birds migrate to warmer places where they can find food more easily.
- Some mammals (e.g., bears) hibernate during the cold winter months.
Hibernation is an inactive, sleeplike state that some animals enter during the winter. Animals that hibernate protect themselves against the cold and reduce their need for food. A hibernating animal's body temperature is lower than normal, and its heartbeat and breathing slow down greatly. An animal in this state needs little energy to stay alive and can live off fat stored in its body. Thus, hibernating animals can more easily survive the cold winter months.