6.3a The interrelationships and interdependencies of organisms affect the development

of stable ecosystems.

6.3b Through ecological succession, all ecosystems progress through a sequence of

changes during which one ecological community modifies the environment, making it

more suitable for another community. These long-term gradual changes result in the

community reaching a point of stability that can last for hundreds or thousands of years.

6.3c A stable ecosystem can be altered, either rapidly or slowly, through the activities of

organisms (including humans), or through climatic changes or natural disasters. The

altered ecosystem can usually recover through gradual changes back to a point of long-

term stability..