When we speak of temperate forests, we refer to forests that occur between 250 and 500 on both sides of the Equator. During the Cenozoic Era, 65.5 million years ago the Earth started to cool. Hot wet climates became restricted to the Equatorial regions. Further North and South of the Equator the climate became distinctly cooler and drier. The four seasons became clearly distinct. Species of vegetation that could not adapt to this change became extinct. Others adapted to form the temperate forests.
Temperate forests developed over a vast latitudinal and longitudinal region, having a wide range of climatic conditions. Trees of the temperate forests adapted to suit the specific climatic conditions of their environments. Thus there are many different kinds of trees in the temperate forests.
FACT 1: Temperate forests are forests with a continuous canopy of broad leafed trees. The broad leaf is an adaptation to have a maximum surface that absorbs sunlight. As the forests spread towards the poles, they merge with the boreal forests. Trees of boreal forests have hard cones. In between the temperate and boreal forests mixed forests of both coniferous and broad leafed trees are found.
FACT 2: Temperate forests are divided into two main groups, the deciduous temperate forests and the evergreen temperate forests. Deciduous forests are found mainly in the Northern Hemisphere. Deciduous forests have thin broad leafed trees. The leaves are too thin to survive the winter frost. They photosynthesise for only one season.
FACT 3: In autumn the chlorophyll in the leaves of deciduous trees begins to break up. The leaves lose their green colour and turn beautiful shades of yellow, orange and red. They fall off as winter approaches and the spot where they were attached to the branch is sealed. During winter the trees are bare. In spring, the leaves begin to grow and the forest turns green again.
FACT 4: Animals in deciduous temperate forests either hibernate or migrate in winter. The black bear commonly found in these forests hibernates in winter. Animals that remain active need to adapt to the loss of cover, if they are to escape predators.
FACT 5: There are five zones or layers in a deciduous temperate forest. The first zone is the tree zone. Trees grow to heights of 18 to 30 meters. They include the maple, the elm and the oak. The 2nd zone has smaller trees. The 3rd zone is a shrub zone of species like laurel and huckleberry. Short herbal plants like ferns form the 4th zone. Lichen and mosses grow in the ground zone.
FACT 6: In areas of mild frost free winters, trees in the temperate forests do not shed their leaves in winter. The leaves are thicker and photosynthesise for more than one season. If the area receives a regular year round supply of rain water, the leaves of the trees are broad, as in Australia. If the rainfall is more erratic and low, the leaves are smaller, harder and thicker. These trees are called sclerophyllous and are found in the Mediterranean and Australia. The Eucalyptus, Gum, Acacia and Casurina grow here.
FACT 7: The temperate forests are the second rainiest biome after the tropical rain forests. A biome is a region having similar vegetation. Between 15 and 150 cm of precipitation occurs, including snow. The summers are mild about 210 C and winter temperatures often below freezing.
FACT 8: Most of the original temperate forests of the world have almost completely disappeared. The sclerophyllous forests of the Mediterranean have been cut for timber or cleared for agriculture. In China the broad leafed deciduous forests have suffered the same fate. The deciduous temperate forests of Europe exist only in fairy tales.
FACT 9: Destruction of the forests in Australia was caused by widespread burning by the Aboriginal peoples. In New Zealand the forests were destroyed by Polynesian invaders 1,500 years ago.
FACT 10: The Koala Bear is the best known and most loved inhabitant of the temperate forests of Australia.