To maintain a healthy environment, natural processes must be allowed to continue – even when humans have become part of the landscape. Nature is not static. Rather, it is characterized by continual change, this change coming in the form of different kinds of disturbances. Large scale disturbance, such as fire, sets back the successional clock and many pine savanna species require its presence. Small-scale disturbances also play an important role in the ecology of a forest. These disturbances set the stage where essential natural processes can occur. For example, each time a large tree crashes to the ground it creates a gap that allows sunlight to reach a patch of otherwise shady forest floor. This sunlight will nourish a small shrub thicket in the understory, providing cover for nesting songbirds as well as host plants for insect species.