Bison grazing in winter in Yellowstone National Park in front of young forest recovering from 1988 fire.
In biology, the carrying capacity of an environment (area) is the maximum number of organisms of a particular species that can live there.
Resources (such as food and space) of each particular area are limited, and they limit the number of organisms that can live/survive there.
Forest fires, for example, negatively affect the carrying capacity of forest areas by destroying plants and trees which forest animals need to survive.
If too many organisms live in an environment, it is called overpopulation.
The term "carrying capacity" was originally used to determine the number of animals that could graze on a segment of land. This term is now used for humans too.
The carrying capacity of an environment can change, and humans can have an effect on the carrying capacity. For example, agriculture and irrigation allow feeding more people.
Some things that can change an environment's carrying capacity are pollution and the use of natural resources.
Images for kids
This is a graph of the population due to the logistic curve model. When the population is above the carrying capacity it decreases, and when it is below the carrying capacity it increases.
Summering of milk cows in the Swiss Alps in Valais Canton
A fishery at sunset in Cochin, Kerala, India.