Disturbances are often times ecosystem specific.
So to best understand the different types of disturbances we must always think in terms of specific ecosystems with which they occur.
When we view disturbances in this way we see that the frequency and severity of a disturbance is often closely related to the specific site conditions.
USDA Forest Service - Rocky Mountain Region Archives, USDA Forest Service, www.forestryimages.org
There are many disturbance agents throughout the world which interact with each other as well as with the environment and the biota to create disturbance regimes.
Although we will discuss several specific types of disturbances you should always remember that there are at any one time several different types of disturbances interacting in various ways.