Succession Ecosystems are NOT static, they are constantly changing Natural forces and human activity disturb them Ecological succession - series of changes that occur over time in an ecosystem Organisms occupy a site & change the environment so that other organisms can come in Two Types: Primary succession Secondary succession

Primary Succession Primary succession - happens on surfaces where no soil exists (lifeless ground). Examples after a volcanic eruption after a glacier melts

Primary Succession Steps 1. Pioneer species arrive (lichens): don’t need soil to survive 2. Lichens die & decompose  organic matter mixes with rock to start making soil 3. Mosses & ferns can grow in new soil  die & add more nutrients to soil 4. Grasses & wildflowers can move in  die & add more nutrients to soil 5. Shrubs & trees can survive 6. End in Climax community

Pioneer species Climax Community First set of species to establish themselves Grow rapidly Short lived Do well in bright sunlight where nutrients are abundant Seeds are widely and rapidly disbursed lots of hardwood shade-loving trees

Secondary Succession Secondary succession – ecosystem is disturbed but soil is not removed (previous ecosystem remains) Examples cleared farming fields forest fires flood tornado Soil & seeds still present, so takes shorter amount of time Start with grasses  herbs, shrubs, small trees  hardwood trees (climax community)

Succession Time Line ***Be sure to label each picture Primary Succession Secondary Succession Start with a picture that represents a natural occurrence that would wipe out top soil. Ex: fire, mudslide, deforestation Start with weeds Shrubs/ bushes pine mature hardwoods Start with a picture that represents a natural occurrence that would wipe out top soil. EX: erosion, glacier movement, volcanic eruption. Rocks or Earth’s crust with no top soil. Pioneer Species Small shrubs/bushes Pines Mature hard woods ***Be sure to label each picture

When finished, write 2 paragraphs on your construction paper to describe the following: Paragraph # 1: Primary Succession Explain the steps of succession. What traumatic events would cause this re-growth to occur? What are pioneering plants? What are some examples of these? Explain why this type of succession takes longer than secondary. Paragraph #2: Secondary Succession Explain the steps of secondary succession. Why would pioneer plants not be needed? What do secondary successions have that primary successions do not?