LIMITING FACTOR
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 1917 ▶ |
| Object type | General information |
An essential component, flow or condition whose absence, short supply or excessive concentration acts as a check on growth or even endangers the survival of a population or system.
According to A. LOTKA: “The significance of such limiting factors seems to have been first pointed out by J. LIEBIG: ”The yield (of the soil) depends on the nutrient whose quantity is minimum“.
LOTKA adds: “Limiting factors not only set certain bounds to the growth of the components to which they are thus related, but are competent also to give rise to the phenomenon of moving equilibrium” (1956, p. 97).
This is very important for ecosystems, which may “bounce” from one type of equilibrium to another under the influence of some positive or negative variation in a limiting factor.
G. WEINBERG proposed a “Law of limiting factors”, as a generalization from the economist's Law of Diminishing Returns.(1975, p.45). However, the latter is merely a consequence of the first one, which seems more precisely causal.
In the same vein, J. WARFIELD enounced the following “Law of Limits”: “To any activity in the universe there exists a corresponding set of limits upon that activity, which determines the feasible extend of the activity” (1991, pers.comm.).
WARFIELD states: “The limits may be active or inactive, generic or specific, fixed or movable, autonomous or responsive” (Ibid).
WARFIELD's law is very general. A frequent practical example of responsive limit is the logistic one, whose logistic equation is the mathematical formulation.
It would seem that any “autonomous” limit turns responsive when the encroaching system puts sufficient pressure on the environment.