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Population Ecology. The branches of ecology Population statics Density Distribution Population dynamics Natality Mortality Survivorship curves Life history strategy Age structures Population models Exponential growth Logistic growth The human population.
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The branches of ecology Population statics Density Distribution Population dynamics Natality Mortality Survivorship curves Life history strategy Age structures Population models Exponential growth Logistic growth The human population Population Ecology
Almost every population distribution in nature is clumped. Life history strategies are a series of tradeoffs that maximize the net reproductive rate. Exponential growth is growth at a constant rate, and therefore is rare. Human populations increase as they move through the demographic transition. Human total fertility is falling. Good or bad news? Major Ideas
Exponential Growth Growth rate (r), or rate of change of a population on a per capita basis, is the birth rate minus the death rate: r = b − d The instantaneous growth rate, dN/dt, can be expressed as: dN/dt = rN
From Exponential to Logistic dN/dt = rN The logistic equation takes into account the carrying capacity of the environment: dN/dt = rN [(K − N)/K] The element [(K − N)/K] reflects decline in growth as population size approaches its carrying capacity
Logistic Growth Curve Carrying capacity of the environment (K) Number of individuals (N) Time
