Population density
The number of individuals per unit area (varies depending on species and ecosystem)
Immigration
The movement of individuals into an area, is another factor that can cause a population to grow
Emigration
The movement of individuals out of an area, can cause a population to decrease in size
Exponential growth
Occurs when the individuals in a population reproduce at a constant rate (at first the population grows exponentially but after a while it hits a "maximum
Logistic growth
Occurs when a population's growth slows or stops following a period exponential growth
Carrying capacity
The number that represents the largest number of individuals that a given environment can support
What characteristics are used to describe a population?
Three important characteristics of a population are its geographic distribution, density, and growth rate
What factors affect a population size?
Three factors can affect population size: the number of births, the number of deaths, and the number of individuals that enter or leave the population
What are exponential growth and logical growth?
Exponential growth is when a population increases until it reaches infinity and logical growth is when a population increases exponentially until it stops or slows as resources become less available