Types of Succession Succession is the natural change of an ecosystem over time. As time passes new species will be introduced to ecosystems. The rate of change depends on the previous environment.

Primary Succession There is no previous community There are rocks, no soil. Rocks must break down into soil. This occurs by lichens breaking apart the rock material. Lichens are a symbiotic relationship between a fungus and a photosynthetic partner (usually an algae). Takes a very long time for this succession to occur. Thousands of years EX: Barren land, glaciers, new volcanic islands (Hawaii) 1

Example of when Primary Succession occurs New Volcanic Islands

Another example Glaciers Succession will occur on the new land that is left after the glacier retreats.

Secondary Succession There was a previous community that was destroyed somehow The soil remains from the previous community This means lichens do not need to break down the rocks. Secondary succession is faster than primary succession Hundreds of years EX: forest fire, Flood

Forest Fire in Yellowstone National Park, 1988 The red on the map is the extent of the fire

This photo was taken in Yellowstone National Park near the Old Faithful Geyser in June of 1999, eleven years after the fires. Burned out trees remain standing, although new trees are rising to take their place.

Mount St. Helens before and after the 1980 eruption

Trees were flattened by the shear force of the blast

Mt. St. Helen 1988 Mt. St. Helen 2001

Mt. Saint Helen is not the only volcano The largest volcano in North America is Yellowstone. The red line indicates the size of the volcano caldera

Primary Succession Mature Trees Small trees Small plants and shrubs Rock Lichen: Pioneer species Small plants and shrubs Small trees Mature Trees

Secondary Succession Small sun loving plants Small shrubs and bushes Small trees Mature Trees What step is missing? (What has to happen first for secondary succession to happen?)

Order of Succession Pioneer Organisms  Serel Stages  Climax Community Pioneer Organisms are the first organisms to grow in an area after the land is exposed. Serel Stages are the stages of growth in between the beginning and the mature area. Climax Community is the mature community that will grow in an area.