Succession 4.3 Respond to questions in red.

Key Questions 1.How do communities change over time? 2.Do ecosystems return to normal following a disturbance?

Ecological Succession An observable, predictable change in species and community structure over time.

Two types of succession Primary succession begins in an area that has no existing community. The first species to colonize are the pioneer species.

Two types of succession Secondary succession happens when an existing community is destroyed or disturbed by a natural or man-made disaster. Examples fire, hurricane, clear cut logging. This process occurs faster in secondary succession than in primary succession.

Climax communities The end product of succession is usually a specific and stable community called a climax community. What happens to the number of species as succession progresses towards the climax community?

Why does the process of succession occur? The Earth is a dynamic, ever changing landscape. As change occurs, opportunities for new species present themselves. What process between species allows certain species to be more successful? Why are the “winners” more successful?

Ecosystem recovery Healthy ecosystems often respond by replacing the original community after a natural disturbance. Human disturbance may be too great for this process to take place.

Looks and sounds like Secondary succession What is the difference between primary and secondary succession? Give examples of each.