EEB321H1 Lecture 16: L16 - Ecological Drift
9 Apr 2017
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Document Summary
Neutral theory assumption: for given trophic levels all species are functionally equivalent and competitively identical, patterns emerge due to ecological drift, species relative abundances are drifting through time and space due to random chance. But this seems to not hold up in many studies: most studies show that it fails, challenges our ways of thinking, also brought role of demographic stochasticity (random variation) in structuring. Idea that we can observe pattern and infer underlying process. Looking at this in cases when communities aren"t neutral (aren"t functionally communities equivalent) [1] learn what theory predicts about importance of demographic stochasticity in non-neutral communities. [2] review empirical studies that measure prevalence and impacts of ecological drift. [1] 2 examples of how demographic stochasticity influences ecological drift via dispersal limitation and population growth rates of low abundance species: should be able to come up with scenarios in which we expect drift to increase in community.
