SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystem. c. Relate environmental conditions to successional changes in ecosystems.

LEQ4: How do ecosystems recover from environmental changes?

Ecological Succession Ecological succession is a process of change in the species that make up a community.

Ecological Succession Succession occurs following a disturbance in an ecosystem. Succession regenerates or creates a community after a disturbance. A sequence of biotic changes Damaged communities are regenerated New communities arise in previously uninhabited areas.

Ecological Succession There are two types of succession: Primary Succession Secondary Succession

Ecological Succession Primary Succession is the establishment and development of an ecosystem in an area that was previously uninhabited. Started by pioneer species First organisms to live in a previously uninhabited area. Able to breakdown solid rock into smaller pieces. Example: Lichens, mosses Results in a climax community

Ecological Succession Pioneer species 0-15 years: Moss, lichens, grasses 15-80 years: Shrubs, cottonwoods, Alder thicket 80-115 years: Transition to mature forest 115-200 years: Climax community

Ecological Succession Secondary Succession is the reestablishment of a damaged ecosystem in an area where the soil was left intact. Plants and other organisms that remain start the process of re-growth. Results in climax community Never ends, ecosystems are continuously changing.

Ecological Succession 0-2 years: Horseweed, crab, grass 2-18 years: Shrubs, pine seedlings 18-70 yrs: Forest and young hardwoods 70-100 yrs: Climax community Oak forest