Today, when children begin to receive environmental education in primary school, and environmental issues are not the last in the media, ecology is still a young, complex and mysterious science. Its scientific base is not so great, and complex models are intricate. Nevertheless, knowledge and understanding of the basic laws in this area is the basis of the worldview of modern man. This article will consider one of the main laws of ecology - the law of the minimum, formulated long before the formation of science itself.
To the history of discovery
The law of the minimum was formulated in 1840 by an outstanding chemist, professor at the University of Hesse (Germany) Eustace von Liebig. This scientist and outstanding teacher is also known for the invention of the Liebig refrigerator, which is still used today in chemical laboratories for the fractional separation of chemical compounds. His book "Chemistry as applied to agriculture" actually gave rise to scienceagrochemistry, and to him - the title of baron and two orders of St. Anne. Liebig studied the survival of plants and the role of chemical additives in its increase. So he formulated the law of the minimum or limiting factor, which turned out to be true for all biological systems. And not only for biological ones, which we will demonstrate with examples.
A bit of theory
In ecology, environmental factors are those that have any effect on the body. Physical and chemical factors (abiotic) are temperature, humidity, light, pressure, pH of the environment and other indicators of inanimate nature. All forms of influence and relationships between living organisms are related to biotic factors. This is competition for resources, and the presence of parasites, and intraspecific struggle for survival. In addition, there are also anthropogenic factors - the conditions created by people and their economic activities. They can also be biotic and abiotic. Environmental factors are regularly-periodic, changing strength in accordance with the change of time of day, seasons of the year or tides. In this case, the adaptation of the organism is hereditary in nature, formed over a rather long period. They can be irregular, like storms or tornadoes. And then there is a redistribution of species diversity.
Comfort zone
Most often, environmental factors are tolerated by organisms within certain limits, which are limited by threshold indicators, beyond which the inhibition of the organism's vital activity occurs. This iscritical points of existence. Between them are zones of tolerance (tolerance) and the zone of optimum (comfort) - the range of the beneficial influence of the factor. The minimum and maximum points of the influence of the environmental factor determine the possibilities of the organism's reaction to a specific factor. Going beyond the optimum zone can lead to the following:
- eliminating a species from a specific range (for example, shifting the population range or migrating a species);
- change in fertility and mortality (for example, with sudden changes in environmental conditions);
- to adaptation (adaptation) and the emergence of new species with new phenotypic and genetic characteristics.
The essence of the law of the minimum
The life of a biological system, be it an organism or a population, depends on the action of many factors of a biotic and abiotic nature. The wording of the law of the minimum may vary, but the essence remains the same: when any factor significantly deviates from the norm, then it becomes the most significant for the system and the most critical for life. At the same time, various indicators can act as limiting factors for the body in different periods of time.
Options are possible
All living organisms live and adapt to a complex of environmental factors. And the impact of the factors of this complex is always unequal. The factor can be leading (very important) or secondary. Different factors will be leading for different organisms, and in different periods of the life of one organism forcertain environmental factors may be the main ones. In addition, the same factors can be limiting for some organisms and not limiting for others. For example, sunlight for plants is a necessary element for photosynthesis processes. But for fungi, soil saprotrophs or deep-sea animals, it is not necessary at all. Or the presence of oxygen in the water will be the limiting factor, but its presence in the soil will not.
Terms of use
The Law of the Minimum is limited in its application by two subsidiary principles:
- The law is applicable without clarification only to equilibrium systems, namely, only under conditions of a stationary state of the system, when the exchange of energy and substances of the system with the environment is regulated by their leakage.
- The second principle of applying the law of the minimum is related to the compensatory capabilities of organisms and systems. Under certain conditions, the limiting factor can be replaced by a factor that is not limiting, but is present in sufficient or high content. This will lead to a change in the need for the substance that is available in the minimum amount.
Illustrative illustration
The barrel, named after the scientist, clearly shows the operation of this law. In this broken barrel, the limiting factor is the height of the planks. In accordance with the ecological law of the minimum, repairing it must begin with the smallest board. It is she who is the factor that has most moved away from normal values, optimal for the survival of the organism. Withouteliminating the impact of this factor, it makes no sense to fill the barrel - other factors do not have such a significant effect at a given time.
Where it's thin, it breaks there
It is this proverb that conveys the essence of the law of the minimum in ecology and not only. For example, in agriculture, indicators of the content of mineral substances in soils are taken into account. If the soil contains only 20% of phosphorus from the norm, calcium - 50%, and potassium -95%, then fertilizers that contain phosphorus must be applied first. In the wild, the limiting factor for a deer in summer is the amount of food, and in winter, the height of the snow cover. Or for a pine that grows in a shady forest, the limiting factor will be light, on dry sandy soil - water, and in a swampy area - temperature in summer.
Another such example, not related to ecology. If the right defender in the team is the weakest, then it is from his flank that the enemy is most likely to break through. This is true in sports, in art, in business. A significant mistake of businessmen is often the underestimation of the harm caused by a weak employee, even in secondary positions. After all, it is not for nothing that they say that the quality of a company is determined by the quality of its worst employees. And the strength of a chain always depends on its weakest link.
