BIO130H1 Lecture Notes - Lecture 5: Net Reproduction Rate, Infinitesimal, Exponential Growth
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BIO130H1 Full Course Notes
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Lecture 5: population ecology: models without age structure. Dandelions have no sex and undergo asexual reproduction. Logistic growth model (has time models and allee effects). Growth is stepwise and best for episodic reproduction. In differential equations, time steps are infinitely small. Use calculus, growth is smooth and best suited for speices with continuous reproduction. Per capita change of population change = birth-death=r this is exponential growth. dn/dt = rn r= growth rate. N t = n 0 e r t is exponential growth if r>0. N t = n 0 t is geometric growth if lambda ( ) >0. Both have similar outcome, but have different mathematical expressions. r and lambda in both are constants. No species has kept lambda > or < 1. 0 for a long period. Can"t always grow (verhulst), so there"s a go and a stop term. dn/dt = rn * (k-n)/k where (k-n)/k is the stopping term. K is the carrying capacity of the environment.
