Presentation on theme: "CHANGES IN AN ECOSYSTEM"— Presentation transcript:
1 CHANGES IN AN ECOSYSTEM SUCCESSIONCHANGES IN AN ECOSYSTEM
2 HOW DO WE DEFINE SUCCESSION? Natural, gradual changes in types of species that live in an area; can be primary or secondary.The gradual replacement of one plant community by another due to processes over time.
3 PRIMARY SUCCESSION-Begins in a place without any soil! (ex: sides of volcanoes, landslides, after flooding) -Starts with the arrival of living things such as lichens or mosses that do not need soil to thrive. What do we call these types of plants?
4 LIKE LICHENS….. Tiny but critical Lichens are an important indicator of air quality. They do not like air pollution…. they are very sensitive to it. They live a very long time and help create soil to initiate primary succesion.Also, they have a very cool symbiotic relationship with algae and fungus. They all three get along and use each other!They are a very important food source for animals.
6 HOW DOES SOIL COME ABOUT? The simple plants dies adding more organic material. The soil layer thickens and grasses soon grow, then widlflowers, and other shrubs can now grow. Soon, more species of plants and trees can now thrive. Next, insects, small birds, and mammals move in.
7 SECONDARY SUCCESSIONBegins in a place that already has soil and was once the home of living organisms. Occurs faster and has different pioneer species than primary succession. Example: A forest after a fire.