ECOLOGICAL SUCCESSION

Question: What are the types of Ecological Succession and what are the main causes?

By: Nada Moawad

Grade: 9th

April 28,2012

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.

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.

Primary Succession

Secondary Succession

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.

Compare and Contrast

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

Ecological Succession Over Time

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.