| A | B |
|---|
| population | a group of individuals from a species that live in a habitat |
| growth rate | the change in the number of a population |
| birthrate | the number of births in a population in a time period |
| death rate | the number of deaths in a population in a time period |
| population density | the number of individuals in a certain amount of area |
| dispersion | how the individuals are arranged in a space |
| random dispersion | type of dispersion where there is no pattern |
| uniform dispersion | type of dispersion where individuals are spaced evenly |
| clumped dispersion | type of dispersion where individuals are in clusters |
| immigration | individuals move INTO a population |
| emigration | individuals move OUT of a population |
| demography | the scientific study of human populations |
| age structure | the number of males and females of each age in the population |
| demographic transition | a population with high birth and death rates transitions to one of low birth and death rates |
| density-independent | factors that are NOT dictated by the density of a population |
| density-dependent | factors that ARE dictated by the density of a population |
| limiting factors | any factor that places limits on a population |
| carrying capacity | the largest population the ecosystem can sustain |
| biodiversity | all of the genetically based variety of organisms in the biosphere |
| extinction | a species disappears from all of its range |
| endangered species | a species whose population size is declining and it in danger of extinction |
| invasive species | a species that comes from another area and has no natural predators to control its population |
| ecological succession | series of predictable changes that occurs in a community over time resulting in changing abiotic and biotic factors |
| primary succession | succession that occurs on surfaces where no previous community or soil exists |
| pioneer species | first species to grow or populate an area |
| climax community | stable community that take hundreds of years to develop and will remain unchanged |
| secondary succession | in an area where the natural community has been disturbed but the soil remains |
