The biogeochemical circulation of substances in the biosphere is the most important natural process of the continuous exchange of various elements between the inanimate environment and organisms (animals, plants, etc.). Everything is based on their fundamental characteristics. The most important include the ability to metabolism, to reproduce, to transfer hereditary properties.
Biogeochemical nitrogen cycle
Each element has its own meaning. Nitrogen plays an important role in the composition of various organic compounds. Despite the high percentage of nitrogen in the atmosphere, it is not available to plants and animals. There are reasons for this. Energetically, it is more beneficial for plants to use mineral nitrogen, and for animals - as part of organic compounds.
Molecular nitrogen from the atmosphere is bound by nitrogen-fixing microorganisms and contributes to its accumulation in the soil in the form of ammonia. Others use nitrogen from dead organisms. They also contribute to the accumulation of ammonia. It turns into nitrates, which are actively used by plants. These are, in general terms, the features of the biogeochemicalnitrogen cycle. Consider also the process of metabolism of other natural substances.
Features of the biogeochemical cycle of carbon, sulfur and phosphorus
These chemical elements are necessary for every living organism. However, their vital needs do not end there. Therefore, macroelements are involved in a small biological cycle (the need of organisms for them is quite large): potassium, magnesium, sodium; as well as trace elements: boron, manganese, chlorine, etc.
They enter plants from the soil, although often with precipitation. As part of the phytomass, carbon, sulfur, and phosphorus are consumed by herbivorous consumers and thus enter the trophic chains. However, some animals satisfy the need for these elements bypassing plants. Ungulates visit s alt licks, gnaw out the soil, or eat excrement, old bones. Marine animals absorb s alt directly from the water. In the process of mineralization of dead residues, microorganisms return chemical elements to the soil and water. Thus, their activities contribute to the enrichment of the environment with nutrients.
Ecosystem balance
In a small biogeochemical cycle in the biosphere, an important circumstance is its completeness. In the ecosystem, the input and output of elements is balanced, while difficulties arise mainly with elements that are reserved in the soil.
The balance of the flow of matter and energy determines the stability of the ecosystem - its homeostasis. The biosphere uses external sources of energy, whichensures its orderliness and rather complex structure. Scattered light energy is converted by plants into a concentrated state of chemical bond energy.
At the same time, both the removal of energy from the environment and its transformation do not lead to the formation of waste.
Influence of human activities on biospheric processes
Human intervention in biogeochemical cycles is carried out in various ways. First of all, this is the destruction of the biocomponent of the ecosystem (destruction of plants or change of the territory during the extraction of energy carriers). When organic matter is burned, energy from a concentrated state passes into a dispersed one, which leads to thermal pollution by aerosols and gaseous products of combustion. In a natural ecosystem, the atoms involved in biogeochemical cycles are repeatedly used. This is facilitated by participation in the cycles of light biogenic elements that make up the vital substance.
Human intervention entails introducing into the environment not only an additional amount of its inherent elements, but also new chemical compounds, including those synthesized by man. Many of these are taken up by plants and then fed into the food chain.
An example is lead, mercury compounds, arsenic, etc. The intake of such substances disrupts the natural cycle, changing the balance of elements, or leads to their accumulation in living organisms, reducing their productivity or causing death. Especiallypesticides and heavy metals have a strong destructive effect. Thus, the stability of an ecosystem, its homeostasis can be violated directly or indirectly by human activity.
Ecological pyramid
Let's turn to the most important patterns of functioning of the ecosystem and biogeochemical cycles. Let's use the principle of the ecological pyramid for this. It is built on the basis of the biological mass of trophic equations. The area of any part of such a pyramid is approximately equal to the mass of the substance. Since organisms build their level using the previous one, this area should gradually decrease. Such reduction of each level can be tenfold.
For example, the ecological pyramid, typical for terrestrial ecosystems, in which producers are perennial plants, have a large biomass, although the production process is not of the highest intensity. It is balanced by the annual increase in the mass of herbivorous animals. The pattern of formation of organic mass is called the pyramid rule. There are other varieties of it.
Inverted Pyramid
Take the ecosystem of water bodies. The pyramid built for them may look a little different. It looks like it's upside down. The fact is that short-lived algae multiply very quickly, but are just as intensively consumed by consumers. Therefore, the simultaneously recorded biomass in this case does not reflect the intensity of the production process in the favorable period of the year. If we take into account that large consumers (fish,crustaceans) accumulate and are eaten more slowly, the total mass of consumers is higher.
The production process in the ecosystem enables their successful functioning. It determines the nature of the energy flow in the biosphere. As you know, living organisms are its consumers. The light energy from the sun is used by green plants and leads to the formation of organic molecules, where it is stored in the form of chemical bonds. Part of it is released during the respiration of plants and is used by them for growth, absorption and movement of substances. This is how the biogeochemical cycle is carried out.
Energy Exchange
As you know, there are laws of thermodynamics. Part of the energy is lost, giving off heat. This is the operation of one of the laws. He affirms the obligatory loss of energy in the process of its transformation from one type to another. When accumulated in plant matter, it is used by animals.
The splitting of molecules is accompanied by the release of energy. A significant part of it is used in the process of life of animals, passing from one form to another. These are the processes of biosynthesis and accumulation of energy of new bonds. These are mechanical, electrical, thermal and other types of energy. During its transformation, a part is again lost, giving off heat. Energy gradually moves to another level. At the same time, its loss also occurs when throwing out a part of undigested food (excrement) and in organic waste products of metabolism (excrements).
Processenergy use
Chaos is rare in nature, usually everything is in order. Let's pay attention to some quantitative patterns of the process of using and converting energy. At the first stage, plants use on average about 1% of its income. Sometimes this figure reaches 2%. In the least favorable conditions, it drops to 0.1%. When energy is transferred from producers to consumers of the first order, the efficiency reaches 10%.
Carnivores seem to digest food more efficiently. This is due to the peculiarities of the chemical composition of food and the ease of digestion by animals. Nevertheless, already at the level of consumers of the third order, the amount of incoming energy is very small and is characterized by thousandths of the initial values.
