4.3 ECOLOGICAL SUCCESSION Biosphere Ecosystems Communities Populations Organisms

What is succession? TIME

Is Disturbance a Good Thing? Life is always changing and then responding to that change. Plant (& therefore animal) species are constantly being replaced with more complex species This is called ecological succession

Arrange the pics in the correct order…

Ecological Succession Primary OR Secondary Succession? Depends on starting conditions: –Is there any soil present? –Does not matter if life had been there previously or not

PRIMARY SUCCESSION –Lifeless beginnings –Starts WITHOUT SOIL. Examples: –Bare rock exposed by glaciers or severe erosion –Newly cooled lava –Abandoned highway or parking lot –Newly created shallow reservoir

PRIMARY SUCCESSION Life begins with PIONEER SPECIESLife begins with PIONEER SPECIES Hardy, smallHardy, small Population grows quicklyPopulation grows quickly Grow close to the groundGrow close to the ground Ex: bacteria, moss, lichensEx: bacteria, moss, lichens

SECONDARY SUCCESSION Starts WITH SOIL. start from roots or seeds remaining or seeds carried in by wind or animals Examples: –Abandoned farms –Heavily polluted streams –Ponds from dams or flooding

Climax Community Succession is unpredictable While it generally proceeds from small to tall, each disturbance is unique and each pioneer is unique…leading to unique community developments The most mature community is called the climax community