Older trees may loose branches or become diseased and develop soft spots that animals can make into nesting cavities. Wood ducks may use this hollow sycamore since it is near water. This tree can provide a vantage point for kingfishers and hawks while they hunt. Many birds and mammals may make nests high in the branches.

This dogwood shows immature berries that birds will eat in the fall. Many trees have nuts or fruit that will sustain a wild animal even though humans cannot consume them.

 

Example food webs for generas of trees are available here.

Leaves that fall into a river from trees and shrubs become food and shelter for many aquatic insects, such as dragonflies, mayflies, stoneflies and beetle larvae.

The fallen log or branch must also be recognized as a great center of wildlife. Chipmunks along with many others spend most of their time in decaying fallen logs.