Inverse density dependence and the Allee effect

The Allee effect describes a scenario in which populations at low numbers a re affected by a positive relationship between population growth rate and d ensity, which increases their likelihood of extinction. The importance of t his dynamic process in ecology has been under-appreciated and recent eviden ce now suggests that it might have an impact on the population dynamics of many plant and animal species. Studies of the causal mechanisms generating Allee effects in small populations could provide a key Ito understanding th eir dynamics.