How do ecosystems change?

Flexi Says:
Ecosystems are dynamic, which means they are almost always changing. Sometimes, they change very rapidly, and other times, change happens very slowly, but they are virtually never static. Often, ecosystems change in response to some type of disturbance, such as a fire or flood. Disturbances lead to ecological succession, a process in which the numbers and types of species in an ecosystem change through time. Important cases of ecological succession include primary and secondary succession.