Ecosystems undergo changes in their structure and function as time passes. Some of these changes are minor and only affect a small area, others are the cause of major changes in the species present and affect the ecosystem as a whole. Major changes can be caused by changes in climate, external factors such as fire, trampling or pollution and development due to the system itself. Succession is a result of these changes and is defined …showed first 75 words of 1189 total…

…showed last 75 words of 1189 total…does not begin with pioneer species but with species from intermediate seres. Another example is in the Australian outback where forest fires regularly destroy the forested areas. After only a few days small plants take advantage of the absence of the forests to grow. When further time has passed they are replaced by shrubs which are replaced or are eventually joined by regrown or new trees to restore the climax community to its original state.