- Biotic potential
Biotic potential is the maximum
reproductive capacity of apopulation under optimum environmental conditions. Full expression of the biotic potential of an organism is restricted byenvironmental resistance , any condition that inhibits the increase in number of the population. It is generally only reached when environmental conditions are very favorable. A species reaching its biotic potential would exhibit exponentialpopulation growth and be said to have a highfertility , that is, how many offspring are produced per mother.Biotic Potential is a fundamental species characteristic, defined by Chapman (1925) as "the inherent power of organisms to reproduce and survive" [Chapman, R. N., 1925. Animal Ecology with Special Reference to Insects. Burgess Brook Inc.,Minneapolis. 370 pp. See pp.158-161.] . In 1931, Chapman redescribed it as: "It is a sort of algebraic sum of the number of young produced at each reproduction, number of reproductions over a period of time, sex ratio of the species, and their general ability to survive under given physical conditions." [Chapman, R. N. (1931) Animal Ecology. McGraw-Hill, New York]
Chapman relates to a "vital index": :Vital Index = (number of births/number of deaths)*100
Biotic potential is the highest possible vital index of a species; therefore, when the species has its highest birthrate and lowest mortality rate.
ignificance of Biotic Potential
If the potential value of population increase can be determined, the impact of the environment upon the population also can be determined.
*Compute the biotic potential (potential increase) and subtract the actual or observed value of decrease; this difference represents how effective the environment is in preventing the species from attaining its full potential.
*Chapman called difference between potential and actual value the environmental resistance.Components of Biotic Potential
*Reproductive potential - potential
natality : It is the upper limit to biotic potential (in the absence of mortality.)
*Survival potential: Because reproductive potential does not account for the number of gametes surviving, survival potential is a necessary component of biotic potential; it is thereciprocal ofmortality (in the absence of mortality biotic potential = reproductive potential).Chapman identified two components:
* nutritive potential - the ability to acquire and utilize food for growth and energy.
* protective potential - potential ability of the organism to protect itself against the dynamic forces of the environment.
** assuring successful fertilization (mating).
** care of young.References
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