Intro to Biomes




Science Notes




Lesson 5




Lesson 8









Intro to Biomes



 Deciduous forest scene

The Deciduous Forest Biome

     In this temperate zone biome, rainfall varies from 30 to 60 inches a year. Humidity may be high. Summers are warm, but winters are cold, and there is often snow. There are four definite seasons.

     This biome is home to many kinds of deciduous flowering trees.  Deciduous trees need a growing season of about 120 frost-free days. In spring they draw on their reserve food to make new leaves. This takes time in the cool spring weather. By early summer their leaves have grown, and the trees can use some of the food that the leaves create to build up their energy reserves and make seeds. In the autumn, the leaves change color as the tree draws as much nourishment as possible from them. Then the leaves fall. When the snow comes, only a little of it weighs down the bare branches.

     Many of these trees rely on insects for pollination. Some have beautiful flowers, and fruit that is edible. Many of our fruit trees have come from wild varieties that grow in deciduous forests.   

Many small plants grow in the shade under the trees. Ferns and wild flowers are abundant, and there are many deciduous shrubs, including some berry bushes.  There is ample food for deer and smaller animals such as raccoons, squirrels, foxes, wood mice and chipmunks. Insects and birds abound. However, when the cold of winter comes, many birds migrate southward and some small animals hibernate.

     Larger animals include cougars and bears. Human hunting has reduced their numbers, but they some of them still live in the forests.

    Melting snow in spring, and intermittent rain during the summer, provide water for streams and ponds. Water birds, insects, and fishes are found in this biome. Amphibians such as frogs and salamanders find homes here, and so do some lizards and small snakes. Decomposers include soil bacteria and many kinds of fungi.

     The long summers of this biome support many life forms, but the cold winters still provide formidable challenges. The cold weather and scarcity of food test the endurance of the animals. Plants must find ways to ensure their survival through dormant periods, and to produce enough seeds to continue their species.

 Food Webs in the Deciduous Forest

 A Deciduous Forest Energy Pyramid

 Photographs from Corel CD-ROMs: for viewing only, not for downloading.      More Information.

Copyright ® 1999.   Elizabeth Anne Viau and her licensors.  All rights reserved. This material may be used by individuals for instructional purposes but not sold. Please inform the author if you use it at eviau@earthlink.net