Primary succession is the migration of new species into a barren area, while secondary succession takes place where species are already established. Primary succession happens in areas denuded by lava flow, whereas secondary succession takes place when field becomes forest.

Time Frame

Primary succession usually occurs more slowly than secondary succession because there are fewer nutrients available and species present. Secondary succession sites typically have a base of more organic matter that generates faster growth.

Frequency

Secondary succession is by far the more common type of ecological succession. Few ecological disturbances wipe out all organic matter, so most sites of succession have an already existing matrix of relationships.

Process

The first plants to become established in primary succession are lichens and mosses. Plants that arise in secondary succession grow from roots and seeds already present or migrate to the community by animal or wind.

Examples

Moss growing on a stone wall is an example of primary succession, as is lichen growing on a rock. Examples of secondary succession include farmland returning to forest, grassland recovery after fire, and pine regrowth after clear-cutting.

Significance

Severe human intervention such as strip mining or concentrated pollution can set the stage for primary succession, while human-caused burning and logging gives rise to secondary succession. The study of primary and secondary succession can hold keys to ecosystem recovery.

Source:

Offland Woodland and Wildlife Trust: Secondary Succession

JRank Science Encyclopedia: Succession - Secondary Succession

University of Illinois Life Sciences: Ecosystems in Time

More Information:

Geowords:Two Types of Ecological Succession