Resolving the limitation – regulation debate

Abstract

Many recent ecological studies have demonstrated that animal populations are limited by their food. Examples are presented here to refute the view that natural populations are regulated by negative feedback mortality factors. Additionally, several incorrect statements in a recent publication are discussed, specifically (1) that there is no difference between the concepts of regulation and limitation; (2) that the debate is about what causes the time it takes a population to reach the carrying capacity of its habitat, not what sets that carrying capacity; (3) that the results of a laboratory experiment using a closed population with fixed amounts of food represents what happens in natural open populations with varying supplies of food; (4) that a thermostat analogy can be used, assuming that an “equilibrium” is controlling natural populations “from above” instead of the original steam analogy which says the varying input of a resource “from below” is the controlling factor.