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Succession and Stability. Introduction. Succession : Gradual change in plant and animal communities in an area following disturbance. Primary succession on newly exposed geological substrates. Secondary succession following disturbance that does not destroy soil.
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Introduction • Succession: Gradual change in plant and animal communities in an area following disturbance. • Primary succession on newly exposed geological substrates. • Secondary succession following disturbance that does not destroy soil. • Climax Community: Late successional community that remains stable until disrupted by disturbance.
Community and Ecosystem Stability • Stability: Absence of change. • Resistance: Ability to maintain structure and function in face of potential disturbance. • Resilience: Ability to recover from disturbance.
http://soulchaser.blogspirit.com/images/medium_pdr_0249.jpg • Are populations organized into discrete communities? • Humboldt hiked up Mt. Chimborazo to an elevation of 5878m. • He recorded vegetation along the elevational gradient. • What order? • * Ferns and palms* Grass and lichens* Oak forest* Broad-leaved herbaceous plants* Evergreen shrubs
Are populations organized into discrete communities? • Clements and others (ex. Kuchler map) felt communities were essentially superorganisms
Are populations organized into discrete communities? • Clements idea of distribution
Are populations organized into discrete communities? • Gleason argued for subtle transitions as opposed to sharp boundaries. He suggested a continuum.