Regulating factors
Encyclopedia
In population ecology
, a regulating factor is something that keeps a population
at equilibrium
(neither increasing nor decreasing in size over time).
An example of a regulating factor would be food supply. If the population increases to a certain size, there will be less food for each organism. This will lead to fewer births (a decrease in fecundity
) and more deaths, making a negative growth rate. As there are now fewer animal
s, the amount of food for each organism will increase, meaning the growth rate will become positive. This would lead to a large population size again, and the cycle would start over. Therefore, food is a regulating factor in this scenario, as food supply keeps the population at relative equilibrium.
All regulating factors are density
-dependent, meaning they keep populations at equilibrium by counteracting fluctuations in population size. Other regulating factors of the human population at present are drinking water
supply, amount of arable land (obviously a more fundamental term for food), air pollution
and prevalence of communicable disease. The major regulating factor for the human population in current times is inadequacy of safe drinking water
, since waterborne disease is the principal environmental cause of mortality.
Population ecology
Population ecology is a sub-field of ecology that deals with the dynamics of species populations and how these populations interact with the environment. It is the study of how the population sizes of species living together in groups change over time and space....
, a regulating factor is something that keeps a population
Population
A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
at equilibrium
Punctuated equilibrium
Punctuated equilibrium is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis...
(neither increasing nor decreasing in size over time).
An example of a regulating factor would be food supply. If the population increases to a certain size, there will be less food for each organism. This will lead to fewer births (a decrease in fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
) and more deaths, making a negative growth rate. As there are now fewer animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, the amount of food for each organism will increase, meaning the growth rate will become positive. This would lead to a large population size again, and the cycle would start over. Therefore, food is a regulating factor in this scenario, as food supply keeps the population at relative equilibrium.
All regulating factors are density
Density
The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
-dependent, meaning they keep populations at equilibrium by counteracting fluctuations in population size. Other regulating factors of the human population at present are drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
supply, amount of arable land (obviously a more fundamental term for food), air pollution
Air pollution
Air pollution is the introduction of chemicals, particulate matter, or biological materials that cause harm or discomfort to humans or other living organisms, or cause damage to the natural environment or built environment, into the atmosphere....
and prevalence of communicable disease. The major regulating factor for the human population in current times is inadequacy of safe drinking water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
, since waterborne disease is the principal environmental cause of mortality.