LO6 population ecology part 2

explain how birth and death rates determine population change

shows the arrival and loss of individuals over time

define fertility, natality, fecundity and longevity

fertility: ability to produce offspring

natality: number of births relative to population size offspring/unit time

fecundity: number of offspring/female/unit time

longevity: life span

identify factors that could contribute to differences between potential and realized fecundity

temperature, diet, mating failure, body size limitations, and disease

define net reproductive rate and project population growth using age-specific data

net reproductive rate: average # of female offspring produced by an average female during lifetime

compare and contrast exponential, geometric, and logistic growth models, and interpret growth type from population graphs

exponential: continuous, unlimited growth, overlapping generations. favorable environments with unlimited resources. low populations densities means no competition.

geometric: predicts changes in population size in discrete intervals where birth and death are not continuous processes. found where resources are limited. growth rate not influenced by population size.

logistic: found where environmental limits exist, growth rate is influenced by population size.

explain the concept of stochasticity and analyze how demographic and environmental stochasticity affect population dynamics

stochasticity: random, unpredictable fluctuations that influence population dynamics.

demographic stochasticity: variation in birth rates and death rates occurring in populations from year to year.

environmental stochasticity: random variation in environment that can influence birth rates and death rates in population.

identify factors contributing to population extinction risk

loss of genetic variability and increased vulnerability to demographic and environmental stochasticity.