1. Question: What are the types of Ecological Succession and what are the main causes? By: Nada Moawad Grade: 9 th April 28,2012

2. What is Ecological Succession?  Ecological succession is the gradual process by which ecosystems change and develop over time. Nothing remains the same and habitats are constantly changing.

3. Types of Ecological Succession:  Primary succession: is the series of community changes which occur on an entirely new habitat which has never been colonized before. For example, a newly quarried rock face or sand dunes.  Secondary succession: is the series of community changes which take place on a previously colonized, but disturbed or damaged habitat. For example, after felling trees in a woodland, land clearance or a fire.

4. Primary Succession

5. Secondary Succession

6. Causes of Ecological Succession  Biotic factors: Interactions among the organisms in a community, as called biotic factors, influence the structure, composition and function of a community. In succession, during period of time a community makes the area less favorable for itself and more favorable for the next serial community.  Physiographic factors: Includes physical and chemical factors of the environment such as landslides, erosion, catastrophic factors, etc.

7. Compare and Contrast

8. Climax Community  A stable group of plants and animals that is the end result of the succession process  Does not always mean big trees  Grasses in prairies  Cacti in deserts

9. Ecological Succession Over Time

10. A summary of changes that occur during succession:  Pioneer species colonize a bare or disturbed site. Soil building.  Changes in the physical environment occur (e.g., light, moisture).  New species of plants displace existing plants because their seedlings are able to adapt better and become established in the changed environment.  Newly arriving species alter the physical conditions, often in ways that enable other species to become established.  Animals come in with or after the plants they need to survive.  Eventually a climax community that is more or less stable will become established and have the ability to reproduce itself.