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

14.5 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

14.5 Ecological Succession There are two types of succession. –primary succession — started by pioneer species

14.5 Ecological Succession Primary Succession in a Hemlock-Spruce Forest 0-15 years Moss, Lichen and other pioneer species years Grass, shrubs, and alder thickets fill in years Transition to alder and spruce forest 115+ years Transition to “climax forest of Hemlock & Spruce

14.5 Ecological Succession There are two types of succession. –secondary succession — started by remaining species

14.5 Ecological Succession Secondary Succession in a Oak Hickory Forest 0-2 years Horse-weed, crabgrass, and annual species 2-18 years Grass, shrubs, and pine seedlings years Pine forest, young hardwood saplings 70+ years Transition to “climax forest of Oak and Hickory