Trees are important to the ecosystem.
Trees support the lives of many large and small animals.
They are used for food, shelter, and sites for reproduction. Many animals also use trees for resting, nesting and for places from which to hunt or capture prey.
The major characteristics of a tree that benefits wildlife is size. A good tree for wildlife must be a big tree. Small, decaying trees may support wildlife, but only small animals for a short time.
The large healthy tree that has a few wounds, and a few cavities will have long term benefits for many small and large animals. When the boundaries of the territories begin to shrink, the niche loses one of its major requirements: space to live and reproduce.
Some large animals can only use large trees for shelter.