ECOLOGICAL SUCCESSIONPrimary SuccessionSecondary SuccessionPrimary vs. Secondary Succession
1DefinitionNatural, gradual changes in the types of species that live in an area; can be primary or secondary The gradual replacement of one plant community by another through natural processes over time
2Primary SuccessionBegins in a place without any soil Bare rockSides of volcanoesPost landslidesFlooded areasStarts with the arrival of living things such as lichens (fungus) that do not need soil to surviveCalled PIONEER SPECIES
3Primary Succession: Sand Dune to Forest
44Primary SuccessionSoil starts to form as lichens and the forces of weather and erosion help break down rocks into smaller piecesWhen lichens die, they decompose, adding small amounts of organic matter to the rock to make soil
5Primary SuccessionSimple plants like mosses and ferns can grow in the new soil
6Primary SuccessionThe simple plants die, adding more organic material
The soil layer thickens, and grasses, wildflowers, and other plants begin to take over
7Primary SuccessionThese plants die, and they add more nutrients to the soilShrubs and trees can now survive
8Primary SuccessionInsects, small birds, and mammals have begin to move inWhat was once bare rock now supports a variety of life
9Secondary succession Begins in an area where soil is already present, (ex. a once cultivated field or after a forest fire.)
1414SuccessionOvertime organic substances build up on the lake bottom, making it shallow and warm.
Eventually the lake will turn into a marsh, and then dry land.
15The Circle of Life in Secondary Succession
16TerminologyPioneer speciesfirst species to begin a succession.Climax community the final stage in a succession.
1717Primary vs. Secondary what are the differences?PrimarySecondary1818Primary vs. SecondaryNo soilBeginning Pioneer speciesEnd Climax communitySoil already existsSeeds have suitable soil conditions.Occurs much fasterEnd Climax community