SUCCESSION IN ECOSYSTEMS SUCCESSION defn a series of

SUCCESSION IN ECOSYSTEMS

SUCCESSION (def’n) - a series of changes in a community in which new populations of organisms gradually replace existing ones http: //www. dnr. state. mi. us/publications/pdfs/huntingwildlifehabitat/Landowners_Guide/images/vegetation/trees/forest_succession. gif

PRIMARY SUCCESSION(def’n) - colonization of new sites by communities of organisms (takes place on bare rock )

PRIMARY SUCCESSION� New bare rock comes from 2 sources: �Volcanic lava flow cools & forms rock �Glaciers retreat & expose rock

PIONEER ORGANISMS� (def’n) � ie: - first organisms to colonize a new site lichens are the first to colonize lava rocks

PRIMARY SUCCESSION - Rock

CLIMAX COMMUNITY � (def’n) -a stable, mature community that undergoes little or no succession

CLIMAX COMMUNITY FYI: In most of Virginia, the climax community would be a deciduous oak– hickory forest

PRIMARY SUCCESSION -

KNOWLEDGE CHECK � What is primary succession? � What is a pioneer organism? � Explain how primary succession takes place.

SECONDARY SUCCESSION (def’n) - sequence of community changes that takes place when a community is disrupted by natural disaster or human actions (takes place on existing soil) http: //www. geo. arizona. edu/Antevs/nats 104/00 lect 20 sucn 2. gif

SECONDARY SUCCESSION � ie: A fire levels portions of a forest

SECONDARY SUCCESSION � ie: A farmer plows his field

SECONDARY SUCCESSION -

POND SUCCESSION Question(s): Which would you classify this type of succession as: Primary or Secondary? Defend your answer.

POND SUCCESSION