Limiting factors are agents whose quantitative values go beyond the adaptive capacity of living organisms, which leads to a limitation of their distribution in the corresponding territory.
Thus, limiting
environmental factors affect the geographic distribution range of various species, can provoke a restriction of their growth or even death due to a lack of individual substances, as well as when they are excessive. It should be noted that the influence of environmental factors under certain conditions can change, be limiting or not radically affect
living organisms.Agrochemist J. Liebig established the law of minimum. He argued that the level of yield depends on a factor with minimal quantitative characteristics. I must say that this law is really fair at the level of chemical compounds, but it is limited in nature, since the crop depends on a whole range of factors: the concentration of the corresponding substances, light, temperature, humidity, etc. At the same time, limiting factors negatively affect either independently or in a certain combination.
Despite the close interconnection of environmental agents, they are not able to replace each other, which is indicated in the law of independence of factors, which was deduced by V.R. Williams. So, for example, humidity cannot be replaced by the action of light or
carbon dioxide.
The environmental influence is most clearly described by the law of the limiting factor: even one environmental agent, which is outside its optimum, can cause a stressful state of the body or even its death.
The level that corresponds to the limits of endurance of a certain factor is called the degree of tolerance. It should be noted that this value is not constant. For different organisms, it is different. This range can be narrowed significantly in cases where a factor is affected whose action is close to the body's endurance limit.
It must be said that limiting factors for one species are usual conditions of existence for others. The limit of tolerance for all organisms is the maximum or minimum lethal temperature, beyond which they die. This is due to the fact that the temperature factor is able to affect metabolism and photosynthesis.
Important agents that may have a limiting effect are water, as well as solar radiation. Their lack leads to the cessation of metabolic and energy reactions, which leads to the death of organisms.
Limiting factors are the cause of the appearance of a number of specific adaptive reactions, which are called adaptive. They develop under the influence of three important processes: the variability of living organisms, heredity and natural selection. The main source of adaptive changes are mutations in the genome. They can occur under the influence of both natural and artificial factors, which in some cases are able to change the distribution range of species.
It is worth noting that the accumulation of mutations leads to disintegration phenomena. In the process of evolution, a whole complex of abiotic and biotic factors acts on all organisms . At the same time, successful adaptations arise that help adapt to negative environmental factors, as well as unsuccessful ones that lead to the extinction of a species.