Section 2: Carying Capacity

Defining Carrying Capacity

The main difference between the logistic and exponential equations is the constant K.

K stands for carrying capacity defined as the maximum population size that a given environment can support.

Carrying capacity is determined by any factors that can limit a population in a particular environment by lowering birth rates, increasing death rates, and/or encouraging migration. Examples of limiting factors include availability of food and other resources such as habitat space and water, competition, and prey/predators numbers.

In this graph, the x-axis demonstrates the time (t), the y-axis shows the fish population size (N), and the carrying capacity (K) is demonstrated by the horizontal line. The carrying capacity (K) represents the maximum size the fish population can attain in the habitat. When the fish population reeached its carrying capacity (K), birth rates decrease, death rates increase and/or fish could migrate to other locations (if possible) since the habitat cannot sustain more fish.

Graphical representation of the logistic growth in the fish population, demonstrating the carrying capacity (K)