ENVR 201 Lecture Notes - Zero Population Growth, Infant Mortality, Thomas Robert Malthus
25 Nov 2012
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Natural increase in pop: doubling time: amount of time for pop to double td = 70/r where r is a percent. Immigration: people enter a local pop: emigration: people leave a local pop, biotic potential: maximum rate at which pop could increase. Makes j curve into an s: population crash: like moose of isle royale. When pop is peak 90% starves because theres not enough food. Then they recover and starve again and recover, ad infinitum: density dependent factor: environmental factor whose effect will be affected by density. Ex: predation, disease, and competition: density independent factor: environmental factor that is unaffected by pop density. Ex: severe weather: r selection: (r-strategists, r-selected species) focus energy on high growth rate. In variable/unpredictable environments where long-term survival is unlikely. Ex: dandelions: k selection: species that exist at or near carrying capacity. Therefore priority is to individual survival, not reproduction. Long life spans, slow maturation, late reprod, large body size.
