Ecological Succession

Change and Ecosystems Succession - A series of regular, predictable changes in the structure of a community over time. Succession occurs because as organisms interact with their environment, they change it in ways that make it more suitable for other organisms - the original organisms are then replaced and the process continues

Succession Primary Succession - Begins with bare mineral surfaces or water and total lack of organisms. - new volcanic rock - receding glaciers

Primary Succesion Begins with pioneer species – organisms like lichen which can survive on bare rock and break it down to begin forming soil - as soil forms, the lichens are replaced by small annual plants (plants that live only one season before dying. - the annuals continue the development of soil, and are replaced by more substantial plants – grasses and shrubs (perennials- plants that can live for many years)

Primary Succession The process of change and replacement continues until a Climax Community is reached - once reached a climax community is considered stable – no change will occur as long as environmental conditions remain the same - the process of primary succession is slow taking hundreds of years - soil formation takes a great deal of time

Secondary Succession Occurs in areas which already have soil but which have been disturbed - an abandoned farm, burned or clear cut area are examples - Secondary Succession is much more common than primary succession - like primary succession, secondary succession continues until a climax community is reached -secondary succession occurs much more quickly than primary succession. Why?

Aquatic Succession Vegetation in a pond or lake dies and creates a rich organic sediment - the sediment along with sediment deposited by wind and streams fills in the pond. - the pond becomes a wet meadow - the wet meadow is replaced by forest and eventually climax is reached

Vocabulary to Master Succession Primary Succession Pioneer Species Secondary Succession Climax Community