What Happens Next??

Ecological Succession A disturbance is any change in a community’s environment, large or small. Some disturbances are human caused while others are natural. Following a disturbance, communities undergo succession. Ecological succession is a somewhat predictable series of changes over time.

Two Types of Succession There are two types of Ecological Succession and the type of succession can be determined by the conditions of the environment after the disturbance. The two kinds of succession are: Primary Succession Secondary Succession.

Primary Succession When a disturbance is so severe that no vegetation or soil remains, primary succession occurs. Volcano eruption, glacier moving/melting Species that colonize first and are well adapted for colonization are called pioneer species. Lichens and mosses are great at this. Pioneer species can break down the rocks and expose the dirt and make the area somewhere other species can survive. Primary succession takes hundreds of years.

Primary Succession

Secondary Succession Secondary succession occurs after a disturbance that does not get rid of all vegetation and dirt. Forest fires, logging, floods. Usually occurs faster than primary succession since the soil still remains. Starts with grasses, then shrubs, then trees.

Secondary Succession

What Happens After Succession? The end result of succession is a climax community which can be described as a stable community. Although the community is stable, that does not mean that it is not changing. Disturbances happen all the time, and each disturbance brings change to the community. Each disturbance can result in a different community.

Intermediate Disturbance Hypothesis The Intermediate Disturbance Hypothesis says that biodiversity is highest when the disturbances are moderate and are not too often or rare.

Video Succession-Crash Course (Resources Page)