From the very beginning of our planet’s existence, various processes of energy transfer between living organisms and the environment constantly occur. It is transformed, passes into other forms, binds and dissipates again. The same can be said of any substance that forms the basis of life. Each of them goes through many instances, undergoes repeated changes and eventually returns.
These processes give an idea of what the cycle of substances in nature is. They allow you to track the movement of not only compounds, but also of individual elements. We will try to understand this issue in more detail.
The general concept of the cycle of substances
What is the substance cycle? These are cyclic transitions from one form to another, accompanied by partial loss or dispersion, but having a constant, stable character. That is, any substance or element makes a series of transitions along the steps, while transforming and changing, but in the end it still returns to its original form.
Naturally, over time, there may be partial losses in the amount of the compound or element in question. However, the general scheme is constant and has been preserved for many millennia.
What is the cycle of substances, you can consider an example. The simplest of them is the conversion of organic substances. Initially, all multicellular living beings consist of them. After the completion of their life cycle, their bodies are decomposed by special organisms, and organic compounds are converted into inorganic ones. After these compounds are absorbed by other creatures and inside their body they are restored to their organic form again. Further, the process is repeated and cyclically continues all the time.
The scheme of the cycle of substances in nature makes it clear that nothing arises from nowhere and does not disappear to nowhere. Everything has its beginning, end and transitional forms. These are the basic rules of life. Energy submits to them. Consider the examples of transformations that occur in ecosystems, living things. And also we will understand what is the cycle of substances based on one specific element.
Living matter in nature
The most important substance of the biosphere is living. What it is? This is every representative of wildlife. Together they form biomass. Naturally, it undergoes changes, is a participant in all processes taking place in the environment.
The cycle of living matter can be illustrated by an example of the following kind.
- The first creatures that directly capture the energy of sunlight and transform it into the energy of chemical bonds are plants, blue-green bacteria. This happens due to the chlorophyll pigment during photosynthesis. The result is the synthesis of organic matter from inorganic components. So the first link was formed among the living matter of the biosphere.
- Next are animals that are able to feed directly on plants. As well as omnivores, which include man as well. They consume the first link and transform the organic matter within themselves into another form - inorganic.
- Herbivorous creatures are eaten by carnivores. So substances are already transferred to other organisms.
- Next are those organisms that are able to feed on carnivorous forms. Higher predators. They are the final link in the circulation of organic matter. After their death, the following organisms come into play.
- Detritophages are microorganisms, fungi, protozoa that decompose the dead remains of living things and translate all substances into an inorganic form.
- These compounds (carbon dioxide, water, mineral salts) are used again by plants in the process of creating organic compounds.
Thus, the above scheme of the cycle of substances in nature reflects the transformation of the living component of the biosphere. It all starts with plants and ends with them. A complete cyclic process that has a lot of branches and complex curls.
The circulation of substances in the ecosystem
Any ecosystem is a whole community of various organisms, interconnected by complex relationships in food terms, as well as under the influence of similar environmental conditions.
The cycle of substances in an ecosystem is subject to certain environmental laws. So, a strict subordination of the supply chains is required. The exchange of energy, substances, the circulation of many elements - all this happens between individuals within this ecological group.
Moreover, they are all divided into several groups:
- producers;
- Consumers of the first order;
- second order consumers;
- third-party consumers;
- omnivores;
- reducers or detritophages.
The circuit of the substance cycle may look something like this:
- a plant (producer) produces organic matter;
- herbivorous animal (first-order consumer) converts it into inorganic and other organics;
- a carnivore (second-order consumer) converts to another organics;
- the highest predator (third-order consumer) again partially dissipates it in the form of heat, and partially concentrates it in the form of internal organic substances;
- microorganisms, for example bacteria, fungi and others (reducers or detritophages), decompose dead animal remains and form a mass of inorganic compounds;
- Plants absorb inorganics and again create a number of important organic compounds during photosynthesis, that is, they produce.
Ecosystem substances
Obviously, in one ecosystem in close interaction are two main types of matter: organic and inorganic. From organics it is:
- proteins;
- fats
- carbohydrates.
Inorganic compounds are as follows:
- water;
- carbon dioxide;
- mineral salts;
- a number of important macrocells.
A very important condition for the normal functioning of any ecosystem is a constant influx of solar energy. After all, plants can carry out photosynthesis only under this condition. In addition, the energy, which is the chemical bonds of the compounds, is dissipated in the form of heat in sufficiently large quantities. Therefore, substances cannot circulate unchanged without loss.
The circuit of substances in the meadow
Meadow is a special natural community. After all, it has some differences from all others, for example, from the forest one. What are these differences?
- In the meadow only grass vegetation prevails, consisting of perennial and annual low grasses. Moreover, they differ from each other. The more photophilous are tall, and those that can live in the shade are short.
- Within this community there are no large representatives of the animal world. This is due to the fact that they simply will not have anywhere to hide, because there are no trees.
- Periodically during heavy rains the entire space of the meadow is flooded with water. Hence their other name - jellied or liquid. Under such conditions, far from all living things can exist.
If we talk about the similarities of the meadow and forest, for example, community, then we should highlight the main feature: representatives of plants, insects, rodents, birds, reptiles, amphibians and mammals live in both territories.
The scheme of the cycle of substances in the meadow may have the following form:
- minerals and water that the plant directly consumes from the earth;
- insects that pollinate flowers and allow them to multiply, while eating nectar, that is, organic matter produced by the plant;
- birds and mammals that eat insects and plants, that is, consume organic matter;
- microorganisms that decompose the dead remains of plants and animals and release inorganic substances (mineral salts, water, carbon dioxide).
Meadow cycle example
All links in the example are important. The circulation of substances in the meadow is a necessary condition for the existence of this community. The soil is able to be enriched with useful substances and elements only thanks to the activity of its inhabitants - detritophagous microorganisms, worms, wood lice and other creatures. Without this condition, the plants will lack inorganics for photosynthesis and growth, which means that the organic substance they produce will also be in short supply. Such as starch, cellulose, protein and others. This will lead to a reduction in the number of animals and birds, and hence the organic matter as a whole. Detritophages will suffer as a result, so the cycle will be broken.
The cycle of substances in the meadow can be illustrated by a more specific example. Let's try to make such a scheme.
- Mineral salts, water, carbon dioxide, oxygen consumes chamomile.
- A honeybee pollinates a designated plant and eats its pollen, that is, carbohydrates and proteins.
- The bee-eater and the bee-eater peck the honey bee and consume the organic matter of its body (chitin, protein, carbohydrates).
- Meadow vole and other small rodents and larger species eat the organic component of plants and insects.
- Kestrel (bird) eats rodents and consumes nutrients.
- After death, all animals and insects fall to the ground, where their body is decomposed into constituent compounds by the activity of microorganisms, worms, wood lice and other detritophages.
- As a result, the soil is again saturated with inorganic salts, water and other compounds that absorb plant roots.
Chains and Networks
The cycle of substances and energy, as has already become clear, is closely related to such an environmental concept as a circuit or a power network. After all, any substance is a material, a product that serves as a building material for the formation of the structural parts of cells, tissues and organs.
Each food chain inevitably entails cyclic transformations of substances. And any processes of synthesis and decay require costs or release of energy. Therefore, she is also involved in a single cycle in nature.
Why are there concepts of "circuit" and "power network"? The thing is that the relationship between organisms within the same environmental group is often much more complicated than just an ordinary ordinary chain. After all, the same representative of the animal world can be both a herbivore and a predator. There are omnivores. In addition, many create a competitive environment for production and subsistence, which also leaves its mark on the general plan of relationships within the biogeocenosis.
In these cases, the circuits are closely intertwined and so-called power networks are formed. This is especially noticeable in places densely populated by inhabitants: forest, lake communities, tropical forests, and others.
All power circuits can be divided into two types:
- eating, or grazing;
- decomposition, or detrital.
The main difference between them is that in the first case, everything starts with a living organism - plants. In the second - from dead residues, excrement and other deposits that are processed by microorganisms, worms, and so on.
Energy changes
Energy, like substances, undergoes a series of changes during the processes in ecosystems. All of it is divided into two main types:
During the construction of power circuits, energy just transfers from one form to another. In this case, partial losses occur. After all, it is spent on the vital processes of each creature, dissipated in the form of heat. That is why it is important that solar energy as a primary source constantly replenish the reserves of any community.
Directly in the form of light from the Sun, only such organisms can consume it, such as:
- plants;
- bacteria
- photosynthetic unicellular.
After them, all the energy goes into the following form - chemical bonds of the compounds. In this form, heterotrophic representatives of the biosphere consume it.
The water cycle
We have already indicated that the most important and historically established life process is the cycle of substances in nature. Water is that inorganic compound whose value is especially important and large-scale. Therefore, how its circulation occurs, we will consider in general terms.
- A huge amount of water is concentrated on the surface of our planet in reservoirs of various kinds. These are seas and oceans, swamps, rivers, lakes, streams, man-made structures. From their surface there is a constant evaporation of moisture, that is, water in the form of steam passes into the atmosphere.
- The soil, both its outer and inner parts, also contains a lot of moisture. This is groundwater or groundwater. From the surface, steam enters the atmosphere, from the inner layers it flows into water bodies, and from there it evaporates.
- Condensing in the atmosphere, the water gradually reaches a maximum and begins to return to the earth in the form of precipitation. In winter it is snow, in summer it is rain.
- Plants take an active part in the absorption and transpiration of water, as they carry through it a huge amount.
Thus, the water cycle and the cycle of substances in nature ensure the normal state of any ecosystem, and hence organisms.
Study of the substance cycle in elementary school
In order for children to have an idea of what cyclical changes occur in nature, they should be told about this from the initial stages of education. Children should have knowledge of what the substance cycle is. Grade 3 is a good time for this. During this period, children are old enough to fully understand and absorb information of this kind.
Many educational programs around the world present a good scheme "Cycle of Substances. Grade 3". It reflects the main types of transformations of water, substances, food chains that are characteristic of each ecosystem.
An approximate scheme of the cycle of substances for primary schoolchildren may look like: water and minerals in plants - organic matter in animals - water and mineral salts after the death of plants and animals.
Each stage should be explained by examples and a detailed description to form a clear idea of the ongoing natural processes.