EEB 3408W Lecture Notes - Lecture 19: Marchantiophyta, Prunus Pensylvanica, Continuum Concept
Document Summary
Large scale disturbances = hurricane, fire, volcanic eruption, windstorm, pathogen, floods. Small scale disturbances = individual tree death in a forest, gopher activity. Succession = gradual change of a community over time following disturbance. Primary succession = occurs on newly exposed geological substrates that have not been modified by organisms. Secondary succession = occurs after disturbances that kill members of the community. Examples : fire, windstorms, tree fall, abandoned agriculture fields, logging. Type, frequency, size of area and intensity of disturbance determines resource availability. Continuum concept (curtis) = shifting composition with changing physical factors results in climax communities. Tendency of early or late successional species dependent on. Wind or bird dispersed - many small seeds that travel long distance. Can handle low ph and periodic drought/ fire. Once they arrive, only mortality of the current residents opens space for them. Clarence lehman - succession can be predicted based off of r*