the number of individuals per unit area. tremendously depending on the species and its ecosystem.
the movement of individuals into an area, another factor that can cause population to grow.
the movement of individuals OUT of a population, can cause a population to decrease.
occurs when the individuals in a population reproduce at a constant rate.
occurs when a population's growth slows or stops following a period of exponential growth.
of the environment for a particular species.
a factor that causes population growth to decrease.
density-dependant limiting factor
a limiting factor (includes competition, predation, parasitism, and disease) that depends on population size.
predator- prey relationship
one of the best-known mechanisms of population control.
density-independent limiting factor
affect all populations in similar ways, regardless of the population size. examples are unusual weather, natural disasters, seasonal cycles, and certain human activities like damming rivers and clear-cutting forests.
the study of human populations that examine the characteristics of human populations and attempts to explain how those populations will change over time.
a dramatic change in birth and death rates.
population profiles, which graph the numbers of people in different age groups