AP BIOLOGY

Detailed explanation-1: -Ecosystems only change slowly after natural disturbances. Changes in ecosystems proceed in a fairly predictable way after a disturbance occurs. Ecosystems eventually stop changing.

Detailed explanation-2: -Disturbances act to disrupt stable ecosystems and clear species’ habitat. As a result, disturbances lead to species movement into the newly cleared area (secondary succession). Once an area is cleared there is a progressive increase in species richness and competition between species takes place.

Detailed explanation-3: -Natural disturbances are one way an ecosystem can become unbalanced. As the name implies, natural disturbances have natural causes, such as weather, geological forces, or biological changes. Fires and floods are examples of natural disturbances that force change upon an ecosystem.

Detailed explanation-4: -Disturbance intensity and the pace of recovery The change a terrestrial ecosystem experiences as it recovers from a disturbance depends on the intensity and magnitude of the disturbance. The major mechanisms of recovery in such ecosystems are primary and secondary succession.

Detailed explanation-5: -Ecosystems change, often independently of humans. 2. Natural changes occur continually.