Natural community definition. What is a natural community?

1. What is a community called?

A community is a collection of animals and plants, in which each individual organism has an influence on all the others and at the same time experiences their influence on itself as well. This coexistence benefits all and it allows each individual species to survive. Examples of such communities are moss hummock, meadow, old stump, marsh, steppe, desert, lake, forest.

2. What connections exist in the communities?

In a community, living organisms are connected not only among themselves, but also with inanimate nature. Living beings that make up a community and their environment constantly exchange substances and energy.

3. What is an ecosystem?

An ecosystem is a community of living organisms and the environment in which they live, forming together a single whole.

4. How do ecosystems cycle?

Due to the ability to photosynthesis, green plants (producers) store a large amount of solar energy, transforming it into the energy of chemical bonds of organic substances, and therefore make it available to all other living organisms (consumers).

Destroyers, feeding on the remnants of dead plants, animals, and their secretions, convert organic matter into mineral, which again can be absorbed by plants. Thus the circulation of substances takes place.

Yes, the lake can be called an ecosystem, because in it both the inanimate environment and the community of organisms form a single whole and the circulation of energy and substances takes place.

6. What groups of organisms exist in each ecosystem?

In the ecosystem can be divided into three groups of organisms. These are producers, consumers and destroyers.

7. Who are the manufacturers?

Producers are green plants. Due to the ability to photosynthesis, they store a huge amount of solar energy, converted into energy of chemical bonds of organic substances, and therefore available to all other living organisms.

8. What is the role of consumers?

Consumers are various herbivorous, omnivorous, and predatory animals. They consume organic matter formed by plants. Consumers are the most important link in the circulation of substances.

9. What animals are destroyers?

Destroyers include numerous bacteria, fungi, and soil worms, grave diggers and some other animals. They feed on the remains of dead plants, animals, and their secretions. As a result of their activity, organic substances are converted into minerals and can be re-absorbed by plants.

10. What is the power circuit?

The food chain is a series of organisms in which each previous link is used as food for the next (grass - grasshopper - bird - snake). These food links are established between the organisms that make up the ecosystem. Food chains can intertwine with each other, forming power networks in which many living organisms participate.

Everything that forms the world around us — natural communities characteristic of certain conditions — is an integral system. The elements of this structure directly or indirectly interact with each other. What are the communities? How do they differ from each other? How do natural communities of organisms interact? About this - further in the article.

Biogeocenosis

This definition was first introduced by Vladimir Sukachev, a Russian scientist, a geobotanist. The concept of biogeocenosis (bios - "life", "earth" - ge, koinos - "common") is considered to be a system of a higher level than the biostructure of the "organism". This is due primarily to the fact that the interaction inside is not between organs. Within the framework of biogeocoenosis, relationships occur between different types of living organisms. Together they perform specific functions, ensure the integrity of the biogeocenosis.

Ecosystem

Different types of plants spread across the surface of the planet not evenly, but in accordance with local conditions. As a result, they form natural "groupings." The interaction of living organisms, the conditions of the abiotic zone ensures the unity of the components of the community. This integrity is also called this concept, along with the definition of "biogeocenosis", acts as a description of the natural community. But while these definitions are different characteristics of the system. Thus, the concept of "ecosystem", as a rule, is used in cases where the relationship of elements within a natural community is considered. "Biogeocenosis" is usually used to characterize a specific, defined natural system that occupies a given territory, and its interaction with other "groups". Examples of natural communities are: field, continent, river and others.

Animals and plants

Considering examples of natural communities, it is impossible not to take into account the influence that animals have in these structures. It is often believed that wild animals can freely choose their habitat, live as and where they want. But actually it is not. If we consider examples of natural communities, the composition of animal groups in certain conditions, then we can see not a random, but a quite specific set of species characteristic of a particular system. As a result, concrete relationships between plants and animals are clearly visible. In turn, representatives of flora and fauna interact with microorganisms, which are also located within the boundaries of a single natural range. Natural communities of the seas and oceans differ in species diversity, the conditions in which their members exist, from other ecosystems. But despite this, the general principles of interaction are maintained regardless of the circumstances.

general information

Any natural community is a complex of different organisms. Within the same conditions there are animals, plants, microorganisms. All of them have an impact on each other and are adapted to certain conditions of existence in a particular territory. Inside this "ecosystem" the circulation of various substances is formed and maintained. The scale may be different. The largest can be attributed to the natural community of the seas and oceans. At the same time, smaller ecosystems are included in the larger ones. Thus, the natural community of the swamp may be part of the taiga ecosystem. In addition to natural systems, there are artificial. They are created by man. Such examples of natural communities are ponds, aquariums, zoos and others.

Nutritional relationship within the ecosystem

Regardless of what the natural community is considered (marsh, continent, pond, etc.), various interactions take place within it. The main relationship is food interaction. The main, initial link contributing to the formation of the energy reserve, which includes any natural natural community (seas, taiga and others), are plants. Only they, using the energy of the sun, are able to form from mineral substances, carbon dioxide, present in the water or in the soil, to form Plants are food for phytophagous vertebrates and invertebrates. They, in turn, feed on predators - carnivorous individuals. So there are food links. The food chain looks, in general, as follows: animal plants (herbivorous) are predators. In some cases, such a chain may be complicated by the addition of intermediates. For example, the first predators can be food for the second, those, in turn, for the third and so on. Thus, the natural community may include caterpillars eating plants. These creatures, in turn, are food for any predatory insects that are eaten by insectivorous birds, which are prey for predatory birds. Considering various examples of natural communities, one can see that there are creatures in any ecosystem whose food is waste: dead plants or parts of them (leaves, branches), dead bodies of animals or their excrement. These include, in particular, earthworms, grave beetles, and others. However, the main role in the decomposition of organic substances belongs to bacteria and mold fungi. It is thanks to them that organic substances are changed to mineral compounds, which can be used by plants again. So is the circulation of substances.

Microclimate

Considering any natural community (ocean, continent), one can see, in addition to food, and other connections. So, plants form a certain climate, microclimate. Different factors of the non-living environment — humidity, temperature, air movement, light exposure, and others — under the vegetation cover will have significant differences from those common in the same area. Thus, the natural community is characterized by high humidity during the day. During the day it is cooler and shady, at night, on the contrary, it is much warmer than in open space. Or in the meadow, for example, the humidity and temperature of the earth's surface will differ from those observed on a bare surface. Among other things, vegetation cover prevents erosion - erosion and spraying of the soil. Microclimate affects the livelihoods and species composition of animals that inhabit this area. Individuals choose for their habitat places in which not only there is the necessary food, but in general the climate, temperature, humidity and other conditions will be optimal.

The impact of animal activity on the ecosystem

First of all, many flowering plant varieties are pollinated by insects, and in some cases they are determined by certain species and, if they are absent, plants cannot reproduce. The distribution of seeds in some representatives of the flora is also carried out by animals. In addition, the activities of some species of living beings have a significant impact on the safety of certain conditions in the ecosystem. For example, the leading burrowing lifestyle contributes to the loosening of the soil, as a result of which air and water penetrate deeper and easier, and the decomposition of various organic residues takes place more quickly.

Change of ecosystems with the result of species changes

Such processes can occur under the action of abiotic, biotic factors, as well as as a result of human activity. The change of natural communities due to the influence of the vital activity of different organisms lasts hundreds, thousands of years. The main role in all these processes belongs to plants. There are various examples of natural communities that have been modified by external factors. The rate of change depends on various circumstances. You can consider the ecosystem "lake". The natural community - in this case the reservoir - gradually begins to decrease and shallow. Over time, silt appears on the bottom. Its layer begins to increase: remains of coastal and aquatic animals and plants accumulate, soil particles being washed off the slopes. In the course of how the pond grows shallower, reeds and reeds begin to grow along the banks, and then sedge. So the lake - a natural community of the same type - is modified and becomes a qualitatively different ecosystem. The accumulation of organic residues occurs faster, forming peat deposits. Some species of plants and animals are replaced by others, more adapted for life in new conditions. As a result, a new natural community is formed - a swamp. However, it should be said that changes in the ecosystem continue. As a result, quite unpretentious trees and shrubs can appear. And gradually, a forest will appear on the site of the reservoir.

Ecosystem change due to human activity

Above were examples of natural communities that have changed under natural conditions due to species substitution. It should be noted that the emergence of new plants, animals, microorganisms, fungi and the formation of new conditions is a rather long process, and can last for dozens, hundreds, or even thousands of years. But the change of ecosystems under the influence of human activity occurs much faster. In some cases, it may even be enough for several years to replace another ecosystem instead of one. So, if in the same lake - a natural community with a specific species composition of plants and living beings - they begin to discharge wastewater, household waste, fertilizer from the fields, oxygen present in the water, begins to be spent on oxidation. As a result, the species inhabiting this ecosystem begin to receive less oxygen and other nutrient compounds. This provokes the death of many plants and living beings. As a result, species diversity is significantly reduced. Some plants begin to replace others, water begins to "bloom." Commercial fish are replaced by "low-value" species, many insects, mollusks, and microorganisms disappear. As a result, the once rich ecosystem turns into a decaying reservoir.

Ecological system restoration

If the influence of a person at a certain stage stops (when the state is not completely neglected), then the process of self-restoration begins within the natural community. And in it the main role is again assigned to plants. For example, tall grasses begin to appear on pastures at the end of grazing. A natural process of purification from common single-celled algae, blue-green, is launched in the lake, as a result of which crustaceans, mollusks, and fish begin to appear again. If the trophic and species structure is too simplified and the self-healing process is simply impossible, the person again has to intervene in the ecosystem. But in this case his activity is not aimed at destruction. So, for example, on grasslands they begin to plant grasses, in the forest they plant trees. Reservoirs are cleaned, then they run young fish. Thus, we can conclude that the restoration of the natural community is possible only with partial violations. In this regard, human activity should not exceed the threshold, after which the processes of self-regulation are impossible.

The influence of abiotic factors

The development and change of natural communities occur under the influence of abrupt changes in climatic conditions, fluctuations in solar activity, volcanic eruptions, and mountain-building processes. These and other factors of inanimate nature are called abiotic. They provoke violations of the stability of the habitat of living organisms. It should be said that ecosystems have infinite ability to recover. And if the external influence is above a certain limit, the natural community will be destroyed. The area on which changes will occur will act as a source of environmental imbalance. And even if it is possible to restore the ecosystem, then it can do much more expensive than modern conservation measures.

Factors responsible for the ability of self-regulation of ecosystems

Independent restoration of natural communities becomes possible due to the natural diversity of living beings, which as a result of a long joint evolution adapted to each other. In the case of a decrease in the number of any of the species, the ecological niche vacated by them takes for a while a similar look to it, preventing the development of certain destabilizing processes. But another situation occurs if some link has completely dropped out of the chain. In this case, the "mutual safety net" of the species may not work, some of the resources will no longer be used - an ecological imbalance occurs. In the process of subsequent depletion of the existing species composition, conditions are created for excessive accumulation of organic compounds, colonization of alien species, a sharp increase in the number of insects and other things. As a rule, rare species begin to disappear first. Their scarcity is determined by the demanding of environmental conditions and sensitivity to changes. In a stable natural community, such categories should be present among other groups of organisms. Their presence in the chain is an indicator of the preservation of natural biodiversity in general, the ecological usefulness of the entire system.

Circulation of substances

This process is provided by species that occupy different trophic levels:

1. Producing from inorganic substances organic - producers. First of all, these are green plants.
2. Consumption of phytomass of the 1st order. These include invertebrates and vertebrates herbivores living creatures.
3. Consumers of the 1st order, consumers of the 2nd and higher orders. These include, in particular, predatory fish, spiders, insects, reptiles, amphibians, insectivores, mammals, and carnivorous birds.
4. Decomposing decomposed organic elements decomposers. These mainly include soil organisms.

Studies of full-fledged natural communities show that rare species are present at every trophic level. The highest indicator of ecosystem stability is considered the presence of viable populations of consuments of a higher order. These species are located at the very top of the trophic structure, and their condition largely depends on the state of the system as a whole. One of the most important characteristics for a species is the size of the territory, which is minimally necessary for the existence and development of a viable population.

The concept of a natural community.

In nature, all organisms do not exist alone, but live together, together, interacting with each other - in a community. At the same time, they form peculiar natural complexes of living organisms. They usually contain many different types of plants, fungi and diverse bacteria. They also have many different animals. Such natural communities of living organisms do not arise by chance. They are always due to specific natural conditions - an abiotic environment (i.e., non-living nature).

The naturally occurring community of living organisms, which is characteristic of these specific conditions, is a single natural integrity. Such an interacting unity of diverse organisms and abiotic environment conditions is called natural community   or biogeocenosis   (from the Greek. bios - "life", ge - "earth", koinos - "common").

The concept of biogeocenosis was introduced into science by Russian geo-botanist Vladimir Nikolayevich Sukachev.

Biogeocenosis is a system of a different, higher level than the "organism" biosystem. This is explained by the fact that the biogeocenosis is formed not by the interaction of organs (as in an organism), but by the interaction of different species of living organisms, performing together certain functions in the biogeocenosis and thus ensuring its integral existence.

The structure of the natural community distinguishes four important interacting links. The first link is inorganic substances of the habitat and solar energy. The second link is a large group of various green plants (autotrophs), which create organic substances and store energy in them. The third link is heterotrophs (animals and fungi), which consume organic matter and energy created by plants. The fourth link is also heterotrophs (these are bacteria, fungi, animals), but they decompose dead organic matter to inorganic substances (salts, carbon dioxide, water), return them back to the environment, where they can again be absorbed by green plants (Fig. 1 ).

Fig. one.

The implementation of the circulation of substances and energy flow - the main feature of the natural community (biogeocenosis).

The concept of the ecosystem.

This interaction of living organisms and the conditions of the abiotic environment in the community ensures the unity of its components, which is also called ecological system   or ecosystem .

The concept of "ecosystem" and "biogeocenosis" applies to the same natural phenomenon - the natural community as its different characteristics. The concept of "ecosystem" is usually used when considering the interaction between the individual components within the community itself. And the concept of "biogeocenosis" is usually used when it comes to a given, specific, natural community occupying a certain territory, its interaction with other natural communities.

The value of plants in the natural community.

An essential part of biogeocenosis (ecosystems) are green plants, including trees, shrubs, shrubs and grasses. Growing together and interacting with each other, they appear in the ecosystem as a unity that performs certain functions in the circulation of substances - they create organic substances.

In addition to the main autotrophic function, green plants in the biogeocenosis also perform others: they determine its appearance, affect the condition of the habitat, and participate in determining the species composition of the entire population.

The name of numerous plant species is called biogeocenosis. The plants define the boundaries of the natural community. That is why in the characterization of any biogeocenosis, its important part is the totality of green plants, which is called plant community   or phytocenosis   (from the Greek. Fiton - "plant" and koykos - "common").

All phytocenoses, passing one into another, form the vegetative cover of the Earth, or the vegetation of our planet. And all biogeocenoses create a living cover on Earth.

The natural community includes various plant species, but on homogeneous patches of the earth's surface, in similar soil-climatic conditions, complexes with similar plant composition are usually observed. According to them, it is relatively easy to distinguish one biogeocenosis from another.

For example, a pine forest with a large amount of blueberry growing there is noticeably different from a pine forest in which mosses grow on the soil. Otherwise it looks like a pine forest with green mosses or sphagnum. Pine and spruce forests are quite different. Other plant communities, for example coniferous and deciduous forests, meadow, steppe and marsh communities, differ significantly.

The peculiarity of the natural community   directly depends on the species composition of living organisms from which it is formed. It is characterized by the amount of species represented in it.

For example, if there is a large number of spruce in the natural community, we will not be mistaken if we call it the spruce forest. But if it is equally rich in spruce and birch (or aspen) trees, then it will be another plant community — a mixed forest (for example, birch with sprouts ate). Dubrava is a natural community in which tree species are represented mainly by oak. Oakwood, spruce, pine forest, birch wood - types of natural communities.

The uniqueness of the natural community also depends on the quality of the environmental conditions in which the community is located. The complex of bacteria, fungi, lichens, plants and animals, drawing the means of life from the surrounding abiotic environment, has a strong influence on it. This creates a unique habitat in different conditions inside the biogeocenosis - biotope   (from the Greek. bios - "life" and topos - "place"). A biotope is not a territory occupied by a community, but a complex of ecological environmental conditions inherent in it (the “internal community environment”), in the creation of which the organisms themselves also take part.

The species population in the biogeocenosis does not appear by chance. It is formed gradually over many years. As a result, species are gathered here that are mutually complementary: according to the use of the existing conditions, according to their biological needs, and according to their life forms. This allows you to accommodate a large number of different types of plants and animals in the same area.

A natural community is a living system consisting of many interacting plant species, bacteria, fungi, and animals. Visiting the forest, walking in the meadow or in the steppe, a person must remember that he is only a guest in the "house" where various living creatures dwell. Therefore, he must abide by the rules of conduct adopted in this "house" in order not to harm either the "tenants" or the conditions of their habitat.

The natural community, or biogeocenosis, is the totality of living organisms and the conditions of the abiotic environment in a certain territory. It manifests itself in nature as a whole. An important feature of biogeocenosis is the circulation of substances. The names "biogeocenosis" and "ecosystem" characterize from different positions the same natural phenomenon - the totality of living organisms and the conditions of the abiotic environment.

Natural communities

A natural community is a collection of plants, animals, microorganisms adapted to the conditions of life in a certain territory, affecting each other and the environment. It carries out and maintains the circulation of substances.

We can distinguish different-scale natural communities, for example, continents, oceans, forest, meadow, taiga, steppe, desert, pond, lake. Smaller natural communities are part of larger ones. Man creates artificial communities, such as fields, gardens, aquariums, spaceships.

Each natural community is characterized by a variety of relationships - food, by habitat, etc.

The main form of bonds of organisms in the natural community is food links. The primary, main link in any natural community that creates energy in it is plants. Only plants, using solar energy, can create organic substances from minerals and carbon dioxide in the soil or water. Herbivorous invertebrates and vertebrates feed on plants. They, in turn, feed on carnivorous animals - predators. So in natural communities there are food bonds, food chain: plants - herbivorous animals - carnivores (predators - approx. Biofile.ru). Sometimes this chain becomes more complicated: others may feed on the first predators, while others, in turn, may feed on them. For example, caterpillars eat plants, and caterpillars are eaten by predatory insects, which, in turn, serve as food for insectivorous birds, and those feed by predatory birds.

Finally, the natural community also includes various organisms that feed on wastes: dead plants or their parts (branches, leaves), as well as the corpses of dead animals or their excrement. They may be some animals - grave diggers, earthworms. But the main role in the process of decomposition of organic substances is played by mold fungi and bacteria. They bring the decomposition of organic substances to minerals, which can again be used by plants. In total, the circulation of substances takes place in natural communities.

The change of natural communities can take place under the influence of biotic, abiotic factors and humans. The change of communities under the influence of the vital activity of organisms lasts hundreds and thousands of years. The main role in these processes is played by plants. An example of a community change under the influence of the vital activity of organisms is the process of overgrowing of water bodies. Most lakes gradually grow smaller and smaller. Over time, the remains of aquatic and coastal plants and animals, soil particles washed from the slopes accumulate over time. Gradually a thick layer of silt forms at the bottom. As the lake grows shallower, its banks become overgrown with reeds and reeds, then sedges. Organic residues accumulate even faster, forming peaty deposits. Many plants and animals are replaced by species whose representatives are more adapted for life in new conditions. Over time, on the site of the lake a different community is formed - a swamp. But this change of communities does not stop. Unpretentious to the soil shrubs and trees may appear in the swamp, and eventually the swamp may be replaced by a forest.

Thus, the change of communities occurs because as a result of a change in the species composition of the communities of plants, animals, fungi, microorganisms, the habitat gradually changes and conditions favorable for the habitat of other species are created.

Change of communities under the influence of human activity. If the change of communities under the influence of vital activity of the organisms themselves is a gradual and long process, covering a period of tens, hundreds and even thousands of years, then the change of communities caused by human activity occurs quickly, over several years.

Removal of seeds from the mother plant for a long distance. Methods of distribution of fruits and seeds. Fetus. Bloom. What is the role in the life of the plant flower. The development and ripening of seeds. Collect a logical chain of concepts. Check yourself. What is the fruit. Why the fruits are so different. Guess what. Describe the natural objects of the plan. You pass by a flower. Name the juicy single-seeded fruit. What is the biological meaning in the distribution of seeds.

"Features of early flowering plants" - Chamber opened. Danger of not being pollinated. Violet field. Coltsfoot ordinary. Biological features of early flowering plants. Ozhika hairy. Noble liverwoman. Hairy sedge. Flowers usually have large sizes. Lyutichny anemone. Chistyak spring. Common goose onions. Primroses. Spleen stem leaves. Butterbur is false. Wolf hair

"Shrubs" - Flora. Familiarity with species diversity. Rosehip cinnamon. Types of shrubs. Raspberry garden. Double name. Bird cherry. Vonder Shrubs. Gooseberry ordinary. Common Hawthorn. Black currant. Barberry ordinary. Spiraea hybrid. Mountain ash. Common lilac. Species variety of shrubs.

"Plant Moss" - Aquariums. Annual wanderers. The value of moss in nature. Spread. Forest. Environmental conditions. Compare and complete the table. The structure of moss. The colonists. Mossy. Laboratory work. Moss classes. Sedentary long-livers. Rocks and stones. Compare. Value. Formation of knowledge. Dressing. Cost material. Complete the test. Bryology. Perennial wanderers. Short-time wanderers.

"Lessons of biology" - A bit of theory: the types of dialogues. Stage 6 - the choice of the maximum. ADDITIONAL MATERIAL is used if time is left in the lesson. Stage 4 - selection of tasks for the formation of a metasubject result. Stages of preparation. Setting goals and objectives of the lesson. Former goals: educational developmental educator. The joint work of the teacher and students. Understands that need more information. Objectives within the framework of the GEF: subject meta-subject personality.

"Conditions of seed germination" - the growth of the stem. Beans. Some time later. Active growth. Conditions for seed germination. Bean seeds. Water and heat. In the cold, seeds and plants die. Green color. Stem. Plants in the cold may die. Alive organisms. Plant development from a seed. Seed germination. The influence of the environment on the development of the plant.