ENVB 305 Lecture Notes - Lecture 4: Maximum Sustainable Yield, Logistic Function, Density Dependence
28 Aug 2016
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Document Summary
Determinism- the parameters are set to come up with a determinate answer (due to 0 variance) Environmental stochasticity- unpredictable spatiotemporal fluctuation in environmental conditions. One of the main sources of fluctuation in ecological processes. Demographic stochasticity- unpredictable internal changes in populations which particularly affect small populations (ex: a string of deaths before a birth rather than 1 death followed by 1 birth followed by 1 death etc ) Density dependence- r depends on density (there are limits on growth) Carrying capacity- k, the maximum population that can be supported. Maximum sustainable yield- since maximum growth occurs at k, harvesting populations to maintain them around this level creates the highest yield. There are limited resources (linear density dependence) b" = b an d" = d cn dn/dt = n(b"-d") = n(b - an - d - cn) N(b - an - d - cn) * (b-d/b-d) Use a bell curve with normal distribution x, 62.
