ES101 Lecture Notes - Lecture 15: Insular Biogeography, Ecological Stability, Pioneer Species
Document Summary
Environmental change (distubance creates changes in species, populations and ecological communities. An ecological community begins to develop on a site previously unoccupied by living organisms. An existing community is disrupted (old-growth forest) and a new community (shrubs, weedy species) subsequently develops. Development of an ecological community that resist further change. Ecological communities don(cid:859)t necessarily return to the same (cid:858)state(cid:859) Living systems are (cid:858)sta(cid:271)le(cid:859) but continuously changing. There is no equilibrium to go back to! Greater complexity (species, feedbacks) can mean greater stability- but not always. Goal: resilience in ecological communities, not stability. Environment in which a particular organism lives. Role played by a species in ecosystem or its (cid:862)lifestyle(cid:863) Species naturally associated with a particular ecosystem. Double-crested cormorant & peregrine falcon top predator in their food chain. Species whose importance is crucial to ecosystem (e. g. , castor canadensis) Habitat modification, niche structure, food webs, etc.
