A woodland is made by a group of large perennial trees. They are adapted to the seasons in the following ways. The trunk and branches of the tree are exposed to harsh winter weather but are protected by a coating of bark. This provides a tough surface to protect the more delicate materials beneath which transports food and water through the tree. The bark is also a good insulator and protects the inside of the tree from very cold weather. If the tree did not have bark the water in the trunk would freeze and expand and cut up the wood. When the ice melted the trunk would be weakened and the tree would collapse.

Woodland trees are deciduous. This means that they grow their leaves in spring, make food with them in the spring and summer then let them fall in the fall. They do not keep their leaves all through the year because in winter the roots cannot take in enough water to keep the leaves making food. Deciduous trees have large broad leaves which need large amounts of water. In winter most of the water may be frozen and cannot be taken up by the roots. The trees adapt to this by losing their leaves and growing new ones in the following spring.

When trees grow together to make a woodland they change the conditions in the habitat. For example when the trees were small, sunlight could reach all the ground around them but as the trees grew they increased in height and their branches reached each other to make a kind of roof called a canopy. In summer the leafy canopy blocks out large amounts of sunlight and makes the floor of the wood so shady that few plants can survive there. However some woodland plants are adapted for this and grow flowers and leaves earlier in the year before the trees come into leaf. These plants such as the snowdrop and the bluebell have a food store called a bulb which they use to give them the early growth they need. By the time the leaves on the trees are fully out the leaves of the snow drop and bluebell have made all the food the plants need to survive until the following spring.