Population ecology

Population dispersion patterns

The dispersion of individuals in a population describes their spacing relative to each other. Different species and different populations of the same species can exhibit drastically different dispersion patterns.

Generally, dispersion can follow one of three basic patterns: random,
uniform (evenly spaced or hyper-dispersed), or clumped (aggregated or contiguous; see Figure 1.

Species traits such as territoriality, other social behaviors, dispersal ability, and allelochemistry will shape individual dispersal (i.e., movements within a population), emigration, and immigration, all of which affect population dispersion patterns. In addition to species traits, the distribution of resources or microhabitats links population dispersion patterns to the surrounding abiotic environment. 

Common dispersion patterns are represented above. Figures 1:  A, B, and C represent the spacing of individuals within a population relative to each other. The entire square indicates the entire quadrat, and each small square indicates one sub-quadrat. Figures D, E, and F indicate the number of individuals within each sub-quadrat. Note that Figure D is derived from a randomly dispersed population, and that it indicates a Poisson distribution.