BIOL 2060 Lecture Notes - Lecture 22: Pioneer Species, Floristics, Softwood
19 Apr 2016
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Clements (1916): likened succession to the predictable development of an organism, and called the climax community a superorganism . Each wave of species in a successional sequence facilitated the establishment of the next wave. Gleason (1926): argued that succession proceeded more dynamically and. Individualistic : less predictable and interdependent, based on species" individual characteristics, external conditions and even chance, outcome not always the same climax community, even under similal environmental conditions. Polyclimax: several possible endpoints: aspen birch rich soil: fir/ poor soil: pine. Most modern ecologists lean towards gleason"s succession model: (1) outcome of succession is influenced by: Chance events (2) communities are groups of individuals, not a superorganism (3) climax concept useful, but not a deterministic model. Egler (1954): presented two alternative views of how succession may work, based on. Inhibition: all species may colonize initially, but early arrivals inhibit later arrivals, which only come to colonize when a disturbance occurs (-)
