ENVB 305 Lecture Notes - Lecture 1: Population Ecology, No Age, Doubling Time
29 Aug 2016
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Document Summary
Ecology- positive or negative interactions in abiotic and biotic components of ecosystems in space and time. Population- the number of individuals of a single species in an ecosystem. Community- a group of multiple species in an ecosystem. Modeling to predict changes in numbers over time. Nt = number (n) of individuals at time (t) Nt+1 = nt + b(irths) d(eaths) + i(mmigration) - e(migration) N = b - d is used for closed systems. Birth rate (per capita): b = offspring / (n * t) Death rate (per capita): d = deaths / (n * t) dn/dt = population rate of change = bn dn = (b-d)n = rn r = instantaneous rate of growth per capita. All populations have the potential for exponential (malthusian) growth. Nt = n0 * ert = n0 * t. Doubling time: td = r/ln(2), tripling time: td = r/ln(3) Nt+1 = nt + nt * rd = nt (1+rd) = nt er = .
