BIOL 2060 Lecture Notes - Lecture 22: Climax Community, Superorganism, Pioneer Species
16 Mar 2018
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Document Summary
Similar to the predictable development of an organism (mechanism of succession) Single climax community = superorganism: each wave of species facilitated the establishment of the next wave, predictable serial replacement until climax community. Objection of clements #1: too simplistic, several possible endpoints (polyclimax) Cross of pine and fir in middle: pattern-climax. Objection of clements #2: not always predictable, dispersal affects sequence and climax, chance events. Egler (1954: presented two alternative views of how succession may work, based on clements and gleason, relay-floristics: based on facilitation, thick band = species present. Initial-floristics: based on tolerance: tolerant species become more abundant over time due to environment becoming more tolerable. Inhibition: any species initially - but early arrivals inhibit later arrivals until another disturbance occurs (-: q: which mechanism of succession do you think is most supported by evidence from nature, ex. Glacial moraine, yellowstone park (facilitation: early species, facilitation later species by improving soil quantity and quality.
