Constant populations always reach a certain period of time, since there are a number of restrictive factors governing the growth of their number. They are conditionally divided into two large groups depending and independent of the density.
Factors depending on the density of the population
This group includes parameters that limit the growth of the population depending on the number of its members. For example, the availability of nutrition may be a factor that controls the growth of residents. If the density of biocenosis is low, then a limited food resource can be sufficient to maintain the life of the entire population in this geographical area. However, as the density of the inhabitants increases, the availability of food will become low, and the range will soon reach the maximum throughput. Thus, the amount of food becomes a factor depending on the density that regulates the population. The process of returning the inhabitants to the original amount is usually called regulation.
Regulation of the population in the wild
Denous factors dependent on density, as a rule, are associated with biotic living organisms, and not with the physical characteristics of the environment. These include:
The regulation of the population can also take the form of behavioral or physiological changes in the organisms of the population. For example, lemmings react to high population density, emigrating in groups in search of a new, more spacious habitat.
Factors that are not dependent on the density of the population
Modification is a set of factors governing the population, which do not depend on its density. For example, wild fire can kill a large number of kangaroo, regardless of the density of its population in this area. The probability of the death of animals does not depend on their number.
Other factors that do not depend on the density that regulate the population in their habitat:
Factors independent of density do not limit the size of the population when they go beyond the throughput of the environment. They cause sharp changes in populations and can sometimes cause complete disappearance of biocenosis.
Unlike regulatory factors, modifier factors cannot maintain the number of populations at a constant level. Often they lead to sharp and unstable changes in the number of inhabitants, including the complete destruction of small groups.