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Ecological Succession. Change in an ecosystem that occurs when one community replaces another as a result of changing abiotic and biotic factors. 2 Types of Succession. Primary Succession Secondary Succession. Primary Succession.
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Ecological Succession Change in an ecosystem that occurs when one community replaces another as a result of changing abiotic and biotic factors.
2 Types of Succession • Primary Succession • Secondary Succession
Primary Succession • Establishment of a community in an area where one did not exist before. • Occurs on solidified lava flow, exposed rocks, or a cliff where NO soil is present. • Pioneer species like lichens (combination of fungus and algea) break down the rocks by secreting acids. This forms the soil. • As species die, other organisms invade.
Small weedy plants, ferns, fungi, and insects invade. • Once they die additional soil is created. • Seeds brought in by wind, water and animals begin to grow. • Eventually enough soil is present for shrubs and trees to grow.
Secondary Succession • Change that takes place after a community of organism has been removed, but soil remains intact. • Causes of secondary succession: fire, flood, windstorms, and field clearing. • Mainly plants are the first to grow in a distrubed area, followed by other species. • Occurs faster than primary succession, but still a very slow process.
Draw, Color, and Label • On the top of your page: • Figure 3.3 pg 62-63 • On the bottom of your page: • Figure 3.4 pg 64