›

The concept of an ecosystem. Ecological system: concept, essence, types and levels

The concept of ecosystems and their place in the organization of the biosphere.

The structural unit of the biosphere is the ecosystem.

ecological system is an interconnected, single functional set of living organisms and their habitat. Components Ecosystems are biocenosis (the totality of living organisms) and biotope (place of their life, inanimate components).

ECOSYSTEM = BIOCENOSIS + BIOTOP

Plants and animals occupying a certain biotope(habitat), constitute a living community - a biocenosis. You can compare a biotope with a vessel, and a biocenosis with its contents.

The term "ecosystem" was introduced by the English ecologist Arthur Tansley in 1935. In 1944, V. N. Sukachev proposed the term "biogeocenosis", and V. I. Vernadsky used the concept of "bio-inert body". The main meaning of these concepts is that they emphasize the obligatory presence of relationships, interdependence and cause-and-effect relationships, in other words, the unification of components into a functional whole. An example of an ecosystem is a lake, a forest, etc.

Biogeocenosis and ecosystem are essentially similar concepts, but given by different scientists at different times. Discussions about this among scientists continue to this day. You can also express your point of view on whether these concepts are different or equivalent. Biocenosis occurs only when each species has its own niche and its own habitat, when it has managed to adapt to the surrounding conditions.

The difference between an ecosystem and a biogeocenosis is as follows:

1. the term "ecosystem" is more often used in domestic science;

2. the concept of "ecosystem" has a broader meaning than "biogeocenosis";

3. The term "biogeocenosis" is used only in relation to natural communities, the ecosystem includes the Biosphere, Man and its influence on other components of the community.

Components and composition of the ecosystem

Communities of organisms are connected with the inorganic environment by the closest material and energy ties. Plants can only exist due to the constant supply of carbon dioxide, water, oxygen, and mineral salts.



Heterotrophs live off autotrophs , but need the intake of such inorganic compounds as oxygen and water. The return of biogenic elements to the environment occurs both during the life of organisms and after their death, as a result of the decomposition of corpses. The community forms a certain system with the inorganic medium, in which the flow of atoms, caused by the vital activity of organisms, tends to be closed in a cycle.

A. Tansley considered ecosystems as the main units of nature on the surface of the Earth, covering space of any length (stump and entire Earth). To maintain the circulation of substances in the system, it is necessary to have a stock of inorganic molecules in an assimilated form and four functionally different components: an abiotic environment, producers, consumers, and decomposers.

1. Non-living (abiotic) environment - these are water, minerals, gases, as well as inanimate organic substances and humus.

2 Producers (manufacturers) - living beings capable of building organic substances from inorganic materials of the environment. This work is carried out mainly by green plants, which produce organic compounds from carbon dioxide, water and minerals with the help of solar energy. This process is called photosynthesis. It releases oxygen. Organic substances produced by plants are used for food by animals and humans, oxygen is used for respiration.

3. Consumers - consumers of plant products. Organisms that feed only on plants are called first-order consumers. Animals that eat only (or mainly) meat are called second-order consumers.

4. Reducers (destructors, decomposers) - a group of organisms that decompose the remains of dead creatures, for example, plant remains or animal corpses, turning them back into raw materials (water, minerals and carbon dioxide), suitable for producers, turning these components back into organic substances. Decomposers include many worms, insect larvae and other small soil organisms. Bacteria, fungi and other microorganisms that convert living matter into mineral matter are called mineralizers.

Food chains and ecological pyramids

The sun provides a constant supply of energy, and living organisms eventually dissipate it in the form of heat. In the process of vital activity of organisms, there is a constant circulation of energy and substances, and each species uses only a part of the energy contained in organic substances. The result is a supply chain food chains, food chains , which are a sequence of species that extract organic matter and energy from the original food substance, with each previous link becoming food for the next (Fig. 1).

In 1934, C. Elton proposed the concept of a food chain.

Food chains- this is the transfer of matter and energy through trophic levels (they are built on the principle that each subsequent link feeds on the previous one).

At each trophic level of the ecosystem, there is a struggle for primacy in the possession of food. This allows populations with greater competitiveness (survivability) to survive. The competitiveness of plants depends on the growth rate, fertility, adaptability to abiotic factors, and animals - on fertility, development of the sense organs, speed of movement, endurance, lifestyle.

Picture 1. General scheme the food chain

In any food chain, the body occupies a certain location - an ecological niche. An ecological niche can be occupied by different types of organisms that are similar in nature of nutrition.

The famous ecologist Lindemann in 1942. formulated the law of energy transformation in ecosystems - " law 10%».

Ecological pyramid - it is a graphical representation of relationships in food chains. They are distinguished: by number, by biomass and by energy.

Figure 2 - Ecological pyramid

An ecosystem is any set of interacting living organisms and environmental conditions. The term "ecosystem" was introduced by A. Tensley in 1935.

Basic properties:

1) the ability to carry out the cycle of substances

2) resist external influences

3) produce biological products

Types of ecosystems:

1) microecosystems (a tree trunk in the breeding stage, an aquarium, a small pond, a drop of water, etc.)

2) mesoecosystem (forest, pond, steppe, river)

3) macroecosystem (ocean, continent, natural area)

4) global ecosystem (biosphere as a whole)

The largest ecosystem is biosphere- the shell of the planet, inhabited by living organisms. The thickness of the biosphere is slightly more than 20 km (organisms live above the land surface no higher than 6 km above sea level, descend no deeper than 15 km into the land mass and 11 km into the ocean), but the bulk of living matter is concentrated in the near-surface layer with a thickness of 50 - 100 m is the height of the forest canopy and the depth of penetration of the main mass of roots. Terrestrial and soil animals and microorganisms are concentrated within these boundaries. In the ocean, the most inhabited by plants and animals are sunlit and warmed up to a depth of 10 - 20 m near-surface water layers. More than 90% of plant and animal biomass is concentrated in this thin layer of the biosphere.

Odum proposed a classification of the ecosystem based on biomes. These are large natural ecosystems corresponding to physical and geographical zones. It is characterized by some basic type of vegetation or other characteristic feature of the landscape.

Biome types:

1) terrestrial (tundra, taiga, steppes, deserts)

2) freshwater (flowing waters: rivers, streams, stagnant water: lakes, ponds, wetlands: marshes)

3) marine (open ocean, shelf waters, deep water zones)

Ecologists also use the term "biogeocenosis", proposed by the Soviet botanist V.N. Sukachev. This term refers to the totality of plants, animals, microorganisms, soil and atmosphere on a homogeneous land area. Biogeocenosis is synonymous with ecosystem.

Depending on the impact of human activities, systems are divided into:

1) natural, preserved intact;

2) modified, changed from human activities;

3) transformed, transformed by man.

The ecosystem consists of four main elements:

1. Non-living (abiotic) environment is water, minerals, gases, as well as non-living organic substances and humus.

2. Producers (manufacturers) - living beings capable of building organic substances from inorganic environmental materials. This work is carried out mainly by green plants, which produce organic compounds from carbon dioxide, water and minerals with the help of solar energy. This process is called photosynthesis. It releases oxygen. Organic substances produced by plants are used for food by animals and humans, oxygen is used for respiration.

3. Consumers - consumers of plant products. Organisms that feed only on plants are called first-order consumers. Animals that eat only (or mainly) meat are called second-order consumers.

4. Reducers (destructors, decomposers) - a group of organisms that decompose the remains of dead creatures, for example, plant remains or animal corpses, turning them back into raw materials (water, minerals and carbon dioxide), suitable for producers that convert these components parts back into organic matter. Decomposers include many worms, insect larvae and other small soil organisms. Bacteria, fungi and other microorganisms that convert living matter into mineral matter are called mineralizers.

Nature is extremely economical. The biomass created by organisms (the substance of their bodies) and the energy contained in it are transferred to the rest of the ecosystem: animals feed on plants, predatory animals eat the former, humans eat plants and animals. This process is called the food chain.

In terms of energy input, natural and anthropogenic (man-made) ecosystems are similar. Both natural and artificial (houses, cities, transport systems) ecosystems require energy supply from outside. But natural ecosystems receive energy from an almost eternal source - the Sun, which, moreover, "producing" energy, does not pollute the environment. Man, on the contrary, feeds the processes of production and consumption mainly at the expense of final energy sources - coal and oil, which, along with energy, emit dust, gases, heat and other wastes that are harmful to the environment and cannot be processed within the artificial ecosystem itself. It should not be forgotten that the consumption of even such “clean” energy as electricity (if it is produced at a thermal power plant) leads to air pollution and thermal pollution of the environment.

Ecosystem is the functional unity of living organisms and their environment. The main characteristic features of an ecosystem are its dimensionlessness and lack of rank. The replacement of some biocenoses by others over a long period of time is called succession. Succession occurring on a newly formed substrate is called primary. Succession in an area already occupied by vegetation is called secondary.

The unit of classification of ecosystems is a biome - a natural zone or area with certain climatic conditions and a corresponding set of dominant plant and animal species.

Special ecosystem - biogeocenosis - site earth's surface with similar natural phenomena. The components of biogeocenosis are climatotope, edaphotope, hydrotope (biotope), as well as phytocenosis, zoocenosis and microbiocenosis (biocenosis).

In order to obtain food, a person artificially creates agro-ecosystems. They differ from natural ones in low resistance and stability, but higher productivity.

Ecosystems are the main structural units of the biosphere

The ecological system, or ecosystem, is the basic functional unit in ecology, since it includes organisms and

inanimate environment - components that mutually influence each other's properties, and the necessary conditions for maintaining life in the form that exists on Earth. Term ecosystem was first proposed in 1935 by an English ecologist A. Tensley.

Thus, an ecosystem is understood as a set of living organisms (communities) and their habitat, which, thanks to the circulation of substances, form a stable system of life.

Communities of organisms are connected with the inorganic environment by the closest material and energy ties. Plants can only exist due to the constant supply of carbon dioxide, water, oxygen, and mineral salts. Heterotrophs live off autotrophs, but need inorganic compounds such as oxygen and water.

In any particular habitat, the reserves of inorganic compounds necessary to maintain the vital activity of the organisms inhabiting it would suffice for a short time if these reserves were not renewed. The return of biogenic elements to the environment occurs both during the life of organisms (as a result of respiration, excretion, defecation) and after their death, as a result of the decomposition of corpses and plant residues.

Consequently, the community forms a certain system with the inorganic medium, in which the flow of atoms, caused by the vital activity of organisms, tends to be closed in a cycle.

Rice. 8.1. The structure of biogeocenosis and the scheme of interaction between the components

In the domestic literature, the term "biogeocenosis", proposed in 1940, is widely used. B. HSukachev. According to his definition, biogeocenosis is “a set of homogeneous natural phenomena(atmosphere, rock, soil and hydrological conditions), which has a special specificity of interactions of these constituent components and a certain type of their exchange of matter and energy between themselves and other natural phenomena and is an internally contradictory dialectical unity, which is in constant motion, development.

In biogeocenosis V.N. Sukachev singled out two blocks: ecotope- a set of conditions of the abiotic environment and biocenosis- the totality of all living organisms (Fig. 8.1). An ecotope is often considered as an abiotic environment not transformed by plants (the primary complex of factors of the physical and geographical environment), and a biotope is considered as a set of elements of the abiotic environment modified by the environment-forming activity of living organisms.

There is an opinion that the term "biogeocenosis" to a much greater extent reflects the structural characteristics of the macrosystem under study, while the concept of "ecosystem" primarily includes its functional essence. In fact, there is no difference between these terms.

It should be pointed out that the combination of a specific physical and chemical environment (biotope) with a community of living organisms (biocenosis) forms an ecosystem:

Ecosystem = Biotope + Biocenosis.

The equilibrium (sustainable) state of the ecosystem is ensured on the basis of the circulation of substances (see paragraph 1.5). All components of ecosystems are directly involved in these cycles.

To maintain the circulation of substances in an ecosystem, it is necessary to have a stock of inorganic substances in an assimilated form and three functionally different ecological groups of organisms: producers, consumers, and decomposers.

Producers autotrophic organisms act, capable of building their bodies at the expense of inorganic compounds (Fig. 8.2).

Rice. 8.2. Producers

Consumers - heterotrophic organisms that consume the organic matter of producers or other consumers and transform it into new forms.

decomposers live at the expense of dead organic matter, translating it again into inorganic compounds. This classification is relative, since both consumers and producers themselves partially act as decomposers during their life, releasing mineral metabolic products into the environment.

In principle, the circulation of atoms can be maintained in the system without an intermediate link - consumers, due to the activity of two other groups. However, such ecosystems are found rather as exceptions, for example, in those areas where communities formed only from microorganisms function. The role of consumers in nature is performed mainly by animals, their activity in maintaining and accelerating the cyclic migration of atoms in ecosystems is complex and diverse.

The scale of the ecosystem in nature is very different. The degree of closure of the cycles of matter maintained in them is also not the same, i.e. repeated involvement of the same elements in cycles. As separate ecosystems, one can consider, for example, a pillow of lichens on a tree trunk, and a collapsing stump with its population, and a small temporary reservoir, meadow, forest, steppe, desert, the entire ocean, and, finally, the entire surface of the Earth occupied by life.

In some types of ecosystems, the removal of matter outside their boundaries is so great that their stability is maintained mainly due to the influx of the same amount of matter from outside, while the internal circulation is ineffective. These are flowing reservoirs, rivers, streams, areas on the steep slopes of mountains. Other ecosystems have a much more complete cycle of substances and are relatively autonomous (forests, meadows, lakes, etc.).

An ecosystem is an almost closed system. This is the fundamental difference between ecosystems and communities and populations, which are open systems exchanging energy, matter and information with the environment.

However, not a single ecosystem of the Earth has a completely closed cycle, since the minimum exchange of mass with the environment still occurs.

The ecosystem is a set of interconnected energy consumers doing work to maintain its non-equilibrium state relative to the environment through the use of solar energy flow.

In accordance with the hierarchy of communities, life on Earth is also manifested in the hierarchy of the corresponding ecosystems. The ecosystem organization of life is one of the necessary conditions for its existence. As already noted, the reserves of biogenic elements necessary for the life of organisms on the Earth as a whole and in each specific area on its surface are not unlimited. Only a system of cycles could give these reserves the property of infinity, necessary for the continuation of life.

Only functionally different groups of organisms can support and carry out the cycle. The functional-ecological diversity of living beings and the organization of the flow of substances extracted from the environment into cycles are the most ancient property of life.

From this point of view, the sustainable existence of many species in an ecosystem is achieved through natural habitat disturbances that constantly occur in it, allowing new generations to occupy the newly vacated space.

Ecosystem concept

The main object of study of ecology are ecological systems, or ecosystems. The ecosystem occupies the next place after the biocenosis in the system of levels of wildlife. Speaking of biocenosis, we had in mind only living organisms. If we consider living organisms (biocenosis) in conjunction with environmental factors, then this is already an ecosystem. Thus, an ecosystem is a natural complex (bio-inert system) formed by living organisms (biocenosis) and their habitat (for example, the atmosphere is inert, the soil, the reservoir is bio-inert, etc.), interconnected by the metabolism and energy.

The term "ecosystem" generally accepted in ecology was introduced in 1935 by the English botanist A. Tensley. He believed that ecosystems, “from the point of view of an ecologist, are the basic natural units on the surface of the earth”, which include “not only a complex of organisms, but also the whole complex of physical factors that form what we call the environment of a biome - habitat factors in in the broadest sense." Tensley emphasized that ecosystems are characterized by various kinds of metabolism not only between organisms, but also between organic and inorganic matter. It is not only a complex of living organisms, but also a combination of physical factors.

Ecosystem (ecological system)- the main functional unit of ecology, which is a unity of living organisms and their habitat, organized by energy flows and the biological cycle of substances. This is a fundamental commonality of the living and its habitat, any set of living organisms living together and the conditions for their existence (Fig. 8).

Rice. 8. Various ecosystems: a - ponds of the middle belt (1 - phytoplankton; 2 - zooplankton; 3 - swimming beetles (larvae and adults); 4 - young carps; 5 - pikes; 6 - larvae of horonomids (twitching mosquitoes); 7 - bacteria; 8 - insects of coastal vegetation; b - meadows (I - abiotic substances, i.e. the main inorganic and organic components); II - producers (vegetation); III - macroconsumers (animals): A - herbivores (fillies, field mice, etc.); B - indirect or detritus-eating consumers, or saprobes (soil invertebrates); C - "riding" predators (hawks); IV - decomposers (putrefactive bacteria and fungi)

The concept of "ecosystem" can be applied to objects of varying degrees of complexity and size. An example of an ecosystem would be a rainforest at a particular place and time, inhabited by thousands of species of plants, animals, and microbes living together and bound by the interactions that take place between them. Ecosystems are such natural formations as the ocean, sea, lake, meadow, swamp. An ecosystem can be a hummock in a swamp and a rotting tree in a forest with organisms living on them and in them, an anthill with ants. The largest ecosystem is the planet Earth.

Each ecosystem can be characterized by certain boundaries (a spruce forest ecosystem, a lowland swamp ecosystem). However, the very concept of "ecosystem" is rankless. It has a sign of dimensionlessness, it is not characterized by territorial restrictions. Ecosystems are usually delimited by elements of the abiotic environment, such as topography, species diversity, physicochemical and trophic conditions, etc. The size of ecosystems cannot be expressed in physical units (area, length, volume, etc.). It is expressed by a systemic measure that takes into account the processes of metabolism and energy. Therefore, an ecosystem is usually understood as a set of components of the biotic (living organisms) and abiotic environment, during the interaction of which a more or less complete biotic cycle occurs, in which producers, consumers and decomposers participate. The term "ecosystem" is also used in relation to artificial formations, for example, a park ecosystem, an agricultural ecosystem (agroecosystem).

Ecosystems can be divided into microecosystems(tree in the forest, coastal thickets of aquatic plants), mesoecosystems(swamp, pine forest, rye field) and macroecosystems(ocean, sea, desert).

On the balance in ecosystems

Equilibrium ecosystems are those that "control" the concentrations of nutrients, maintaining their balance with solid phases. The solid phases (the remains of living organisms) are the products of the vital activity of the biota. Equilibrium will be those communities and populations that are part of an equilibrium ecosystem. This type of biological balance is called mobile, since the processes of dying off are continuously compensated by the appearance of new organisms.

Equilibrium ecosystems obey Le Chatelier's principle of sustainability. Consequently, these ecosystems have homeostasis, in other words, they are able to minimize external impact while maintaining internal balance. The stability of ecosystems is achieved not by shifting chemical equilibria, but by changing the rates of biogen synthesis and decomposition.

Of particular interest is the way to maintain the sustainability of ecosystems, based on the involvement in the biological cycle of organic substances previously produced by the ecosystem and deposited "in reserve" - ​​wood and mortmass (peat, humus, litter). In this case, the wood serves as a kind of individual material wealth, while the mortmass serves as a collective wealth that belongs to the ecosystem as a whole. This “material wealth” increases the margin of ecosystem resilience, ensuring their survival in the face of adverse climate change, natural disasters, etc.

The stability of an ecosystem is the greater, the larger it is in size and the richer and more diverse its species and population composition.

Ecosystems of different types use various options individual and collective ways of storing stability with a different ratio of individual and collective material wealth.

Thus, the main function of the totality of living beings (communities) included in the ecosystem is to ensure an equilibrium (sustainable) state of the ecosystem based on a closed circulation of substances.

ecological system

Ecosystem or ecological system(from the Greek óikos - dwelling, location and system), a natural complex (bio-inert system) formed by living organisms (biocenosis) and their habitat (inert, for example, the atmosphere, or bio-inert - soil, water, etc.), associated interchange of matter and energy. One of the basic concepts of ecology, applicable to objects of varying complexity and size. Examples of Ecosystems - a pond with plants living in it, fish, invertebrates, microorganisms, bottom sediments, with its characteristic changes in temperature, the amount of oxygen dissolved in water, the composition of water, etc., with a certain biological productivity; a forest with forest floor, soil, microorganisms, with birds, herbivores and predatory mammals inhabiting it, with its characteristic distribution of temperature and humidity of air, light, soil water, and other environmental factors, with its inherent metabolism and energy. A rotting stump in the forest, with organisms and living conditions living on it and in it, can also be considered as an Ecosystem

Basic information

Ecological system (ecosystem) - a set of populations of various species of plants, animals and microbes interacting with each other and their environment in such a way that this set is preserved indefinitely. Examples of ecological systems: meadow, forest, lake, ocean. Ecosystems exist everywhere - in water and on land, in dry and humid areas, in cold and hot areas. They look different, include different types of plants and animals. However, in the "behavior" of all ecosystems there are also common aspects related to the fundamental similarity of the energy processes occurring in them. One of the fundamental rules that all ecosystems obey is Le Chatelier-Brown principle :

with an external influence that brings the system out of a state of stable equilibrium, this equilibrium is shifted in the direction in which the effect of the external influence is weakened.

When studying ecosystems, first of all, the flow of energy and the circulation of substances between the corresponding biotope and biocenosis are analyzed. The ecosystem approach takes into account the common organization of all communities, regardless of habitat. This confirms the similarity of the structure and functioning of terrestrial and aquatic ecosystems.

According to the definition of V. N. Sukachev, biogeocenosis (from the Greek bios - life, ge - Earth, cenosis - society) - it is a set of homogeneous natural elements (atmosphere, rocks, vegetation, wildlife and the world of microorganisms, soil and hydrological conditions) in a certain area of ​​the Earth's surface. The contour of the biogeocenosis is established along the border of the plant community (phytocenosis).

The terms "ecological system" and "biogeocenosis" are not synonymous. An ecosystem is any collection of organisms and their habitat, including, for example, a flower pot, an anthill, an aquarium, a swamp, a manned spaceship. At listed systems a number of signs from Sukachev's definition are missing, and first of all, the element "geo" - the Earth. Biocenoses are only natural formations. However, the biocenosis can be fully considered as an ecosystem. Thus, the concept of "ecosystem" is broader and fully covers the concept of "biogeocenosis", or "biogeocenosis" - this is a special case of "ecosystem".

The largest natural ecosystem on Earth is the biosphere. The boundary between a large ecosystem and the biosphere is as arbitrary as between many concepts in ecology. The difference mainly consists in such a characteristic of the biosphere as globality and a large conditional closure (with thermodynamic openness). Other ecosystems of the Earth are practically not closed materially.

Structure of ecosystems

Any ecosystem can first of all be divided into a set of organisms and a set of non-living (abiotic) factors of the natural environment.

In turn, the ecotope consists of the climate in all its diverse manifestations and the geological environment (soils and soils), called the edaphotope. Edaphotope is where the biocenosis draws its livelihood and where it releases waste products.

The structure of the living part of the biogeocenosis is determined by tropho-energy connections and relationships, according to which three main functional components are distinguished:

complex autotrophic producer organisms that provide organic matter and, consequently, energy to other organisms (phytocenosis (green plants), as well as photo- and chemosynthetic bacteria); complex heterotrophic consumer organisms living off nutrients created by producers; firstly, it is a zoocenosis (animals), secondly, chlorophyll-free plants; complex decomposer organisms that decompose organic compounds to a mineral state (microbiocenosis, as well as fungi and other organisms that feed on dead organic matter).

As a visual model of the ecological system and its structure, Yu. Odum suggested using a spacecraft during long journeys, for example, to planets solar system or even further. Leaving the Earth, people should have a clearly limited closed system that would provide all their vital needs, and use the energy of solar radiation as energy. Such a spacecraft must be equipped with systems for the complete regeneration of all vital abiotic components (factors) that allow their repeated use. It must carry out balanced processes of production, consumption and degradation by organisms or their artificial substitutes. In fact, such an autonomous ship will be a micro-ecosystem that includes a person.

Examples

A forest area, a pond, a rotting stump, an individual inhabited by microbes or helminths are ecosystems. The concept of an ecosystem is thus applicable to any set of living organisms and their habitats.

Literature

  • N.I. Nikolaikin, N.E. Nikolaykina, O.P. Melekhov Ecology. - 5th. - Moscow: Drofa, 2006. - 640 p.

see also

Links

  • Ecosystem - Ecology News

Wikimedia Foundation. 2010 .

  • Ecologist
  • Environmental factors

See what "Ecological system" is in other dictionaries:

    ecological system- a single natural or natural-anthropogenic complex formed by living organisms and their habitat, in which living and inert ecological components interconnected by causal relationships, metabolism and distribution ... ... Financial vocabulary

    ecological system- ENVIRONMENTAL, oh, oh. Dictionary Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

    ecological system- a single complex natural complex formed by living organisms and their habitat (atmosphere, soil, water bodies, etc.), in which living and non-living components are interconnected by the exchange of matter and energy, forming together a stable integrity ... Emergencies Dictionary

    ECOLOGICAL SYSTEM- ECOLOGICAL SYSTEM, an ecosystem, a natural complex formed by living organisms and their habitat, interconnected by the exchange of substances and energy. One of the main concepts of ecology, applicable to objects of varying complexity and size. ... ... Demographic Encyclopedic Dictionary

    ECOLOGICAL SYSTEM- A single natural or natural anthropogenic complex formed by living organisms and their habitat, in which living and inert ecological components are interconnected by causal relationships, metabolism and distribution ... ... Glossary of business terms

    ecological system- ecosystem - [A.S. Goldberg. English Russian Energy Dictionary. 2006] Topics energy in general Synonyms ecosystem EN ecological system ... Technical Translator's Handbook

    ECOLOGICAL SYSTEM- ECOSYSTEM... Legal Encyclopedia

The ecosystem includes all living organisms (plants, animals, fungi and microorganisms), which, to one degree or another, interact with each other and their inanimate environment (climate, soil, sunlight, air, atmosphere, water, etc.) .).

The ecosystem has no definite size. It can be as big as a desert or a lake, or as small as a tree or a puddle. Water, temperature, plants, animals, air, light and soil all interact together.

The essence of the ecosystem

In an ecosystem, each organism has its own place or role.

Consider the ecosystem of a small lake. In it, you can find all kinds of living organisms, from microscopic to animals and plants. They depend on things like water, sunlight, air, and even the amount of nutrients in the water. (Click to learn more about the five basic needs of living organisms).

Lake ecosystem diagram

Any time an "outsider" (a living being(s) or an external factor such as rising temperatures) is introduced into an ecosystem, catastrophic consequences can occur. This is because the new organism (or factor) is capable of distorting the natural balance of interaction and causing potential harm or destruction to the non-native ecosystem.

Generally, the biotic members of an ecosystem, together with their abiotic factors, depend on each other. This means the absence of one member or one abiotic factor can affect the entire ecological system.

If there is not enough light and water, or if the soil is low in nutrients, the plants may die. If the plants die, the animals that depend on them are also at risk. If animals that depend on plants die, other animals that depend on them will also die. The ecosystem in nature works the same way. All of its parts must function together to maintain balance!

Unfortunately, ecosystems can be destroyed by natural disasters such as fires, floods, hurricanes, and volcanic eruptions. Human activity also contributes to the destruction of many ecosystems and.

Main types of ecosystems

Ecological systems have indefinite dimensions. They are able to exist in a small space, for example, under a stone, a rotting tree stump or in a small lake, and also occupy large areas (like the entire rainforest). From a technical point of view, our planet can be called one huge ecosystem.

Diagram of a small rotting stump ecosystem

Types of ecosystems depending on the scale:

  • microecosystem- a small scale ecosystem like a pond, puddle, tree stump, etc.
  • mesoecosystem- an ecosystem, such as a forest or a large lake.
  • Biome. A very large ecosystem or collection of ecosystems with similar biotic and abiotic factors, such as an entire rainforest with millions of animals and trees, and many different water bodies.

Ecosystem boundaries are not marked with clear lines. They are often separated by geographical barriers such as deserts, mountains, oceans, lakes, and rivers. Since boundaries are not strictly fixed, ecosystems tend to merge with each other. This is why a lake can have many smaller ecosystems with their own unique characteristics. Scientists call this mixing "Ecoton".

Types of ecosystems by type of occurrence:

In addition to the above types of ecosystems, there is also a division into natural and artificial ecological systems. A natural ecosystem is created by nature (forest, lake, steppe, etc.), and an artificial one is created by man (garden, garden plot, park, field, etc.).

Ecosystem types

There are two main types of ecosystems: aquatic and terrestrial. Every other ecosystem in the world falls into one of these two categories.

Terrestrial ecosystems

Terrestrial ecosystems can be found anywhere in the world and are subdivided into:

forest ecosystems

These are ecosystems in which there is an abundance of vegetation or a large number of organisms living in a relatively small space. Thus, the density of living organisms in forest ecosystems is quite high. A small change in this ecosystem can affect its entire balance. Also, in such ecosystems you can find a huge number of representatives of the fauna. In addition, forest ecosystems are divided into:

  • Tropical evergreen forests or tropical rainforests: receiving an average rainfall of more than 2000 mm per year. They are characterized by dense vegetation dominated by tall trees located at different heights. These territories are a refuge for various species of animals.
  • Tropical deciduous forests: Along with a huge variety of tree species, shrubs are also found here. This type of forest is found in quite a few parts of the world and is home to great variety representatives of flora and fauna.
  • : They have quite a few trees. It is dominated by evergreen trees that renew their foliage throughout the year.
  • Broad-leaved forests: They are located in humid temperate regions that have sufficient rainfall. During the winter months, the trees shed their leaves.
  • : Located directly in front, the taiga is defined by evergreen conifers, sub-zero temperatures for six months and acidic soils. In the warm season, you can meet a large number of migratory birds, insects and.

desert ecosystem

Desert ecosystems are located in desert regions and receive less than 250 mm of precipitation per year. They occupy about 17% of the entire land mass of the Earth. Due to the extremely high air temperature, poor access to and intense sunlight, and not as rich as in other ecosystems.

grassland ecosystem

Grasslands are located in the tropical and temperate regions of the world. The area of ​​the meadow mainly consists of grasses, with a small number of trees and shrubs. The meadows are inhabited by grazing animals, insectivores and herbivores. There are two main types of meadow ecosystems:

  • : Tropical grasslands that have a dry season and are characterized by singly growing trees. They provide food for a large number of herbivores, and are also a hunting ground for many predators.
  • Prairies (temperate grasslands): This is an area with a moderate grass cover, completely devoid of large shrubs and trees. In the prairies, forbs and tall grass are found, and arid climatic conditions are also observed.
  • Steppe meadows: Territories of dry grasslands, which are located near semi-arid deserts. The vegetation of these grasslands is shorter than in the savannas and prairies. Trees are rare, and usually found on the banks of rivers and streams.

mountain ecosystems

The highlands provide a diverse range of habitats where a large number of animals and plants can be found. At altitude, harsh climatic conditions usually prevail, in which only alpine plants can survive. Animals that live high in the mountains have thick fur coats to protect them from the cold. The lower slopes are usually covered with coniferous forests.

Aquatic ecosystems

Aquatic ecosystem - an ecosystem located in an aquatic environment (for example, rivers, lakes, seas and oceans). It includes aquatic flora, fauna, and water properties, and is divided into two types: marine and freshwater ecological systems.

marine ecosystems

They are the largest ecosystems that cover about 71% of the Earth's surface and contain 97% of the planet's water. Sea water contains a large amount of dissolved minerals and salts. The marine ecological system is divided into:

  • Oceanic (relatively shallow part of the ocean, which is located on the continental shelf);
  • Profundal zone (deep water area not penetrated by sunlight);
  • Bental region (area inhabited by benthic organisms);
  • intertidal zone (a place between low and high tides);
  • Estuaries;
  • Coral reefs;
  • Salt marshes;
  • Hydrothermal vents where chemosynthetic feeders.

Many types of organisms live in marine ecosystems, namely: brown algae, corals, cephalopods, echinoderms, dinoflagellates, sharks, etc.

Freshwater ecosystems

Unlike marine ecosystems, freshwater ecosystems cover only 0.8% of the Earth's surface and contain 0.009% of the world's total water supply. There are three main types of freshwater ecosystems:

  • Stagnant: Waters where there is no current, such as pools, lakes or ponds.
  • Flowing: Fast moving waters such as streams and rivers.
  • Wetlands: places where the soil is permanently or intermittently flooded.

Freshwater ecosystems are home to reptiles, amphibians and about 41% of the world's fish species. Fast moving waters usually contain a higher concentration of dissolved oxygen, thereby supporting more biodiversity than the stagnant waters of ponds or lakes.

Structure, components and factors of the ecosystem

An ecosystem is defined as a natural functional ecological unit consisting of living organisms (biocenosis) and their inanimate environment (abiotic or physico-chemical), which interact with each other and create a stable system. Pond, lake, desert, pasture, meadow, forest, etc. are common examples of ecosystems.

Each ecosystem consists of abiotic and biotic components:

Ecosystem structure

Abiotic components

Abiotic components are unrelated factors of life or the physical environment that influence the structure, distribution, behavior and interaction of living organisms.

Abiotic components are mainly represented by two types:

  • climatic factors which include rain, temperature, light, wind, humidity, etc.
  • Edaphic factors, including soil acidity, topography, mineralization, etc.

Importance of abiotic components

The atmosphere provides living organisms carbon dioxide(for photosynthesis) and oxygen (for respiration). The processes of evaporation, transpiration and occur between the atmosphere and the surface of the Earth.

Solar radiation heats the atmosphere and evaporates water. Light is also essential for photosynthesis. provides plants with energy for growth and metabolism, as well as organic products to feed other life forms.

Most living tissue is made up of a high percentage of water, up to 90% or more. Few cells are able to survive if the water content falls below 10%, and most of them die when the water content is less than 30-50%.

Water is the medium through which mineral food products enter the plants. It is also essential for photosynthesis. Plants and animals get water from the Earth's surface and soil. The main source of water is atmospheric precipitation.

Biotic Components

Living things, including plants, animals, and microorganisms (bacteria and fungi) present in an ecosystem are biotic components.

Based on their role in the ecological system, biotic components can be divided into three main groups:

  • Producers produce organic substances from inorganic substances using solar energy;
  • Consumers eat ready organic matter produced by producers (herbivores, predators and);
  • Reducers. Bacteria and fungi that destroy dead organic compounds of producers (plants) and consumers (animals) for nutrition, and emit simple substances (inorganic and organic) into the environment, formed as by-products of their metabolism.

These simple substances are re-produced as a result of cyclical exchange of substances between the biotic community and the abiotic environment of the ecosystem.

Ecosystem levels

To understand the layers of an ecosystem, consider the following figure:

Ecosystem Tier Diagram

Individual

An individual is any living being or organism. Individuals do not breed with individuals from other groups. Animals, unlike plants, are usually included in this concept, since some representatives of the flora can interbreed with other species.

In the diagram above, you can see that the goldfish is interacting with environment and will breed exclusively with members of its own species.

population

A population is a group of individuals of a given species that live in a particular geographic area at a given time. (An example is the goldfish and representatives of its species). Note that a population includes individuals of the same species that may have various genetic differences such as coat/eye/skin color and body size.

Community

The community includes all living organisms in a certain area at a given time. It may contain populations of living organisms different types. In the diagram above, notice how goldfish, salmon, crabs, and jellyfish coexist in a particular environment. A large community usually includes biodiversity.

Ecosystem

An ecosystem includes communities of living organisms interacting with the environment. At this level, living organisms depend on other abiotic factors such as rocks, water, air, and temperature.

Biome

In simple terms, it is a collection of ecosystems that have similar characteristics with their abiotic factors adapted to the environment.

Biosphere

When we look at different biomes, each of which transitions into another, a huge community of people, animals and plants is formed, living in certain habitats. is the totality of all ecosystems present on Earth.

Food chain and energy in an ecosystem

All living beings must eat to get the energy they need to grow, move, and reproduce. But what do these living organisms eat? Plants get their energy from the sun, some animals eat plants and others eat animals. This ratio of feeding in an ecosystem is called the food chain. Food chains generally represent the sequence of who feeds on whom in a biological community.

The following are some of the living organisms that can fit in the food chain:

food chain diagram

The food chain is not the same as. The trophic web is a combination of many food chains and is a complex structure.

Energy transfer

Energy is transferred along food chains from one level to another. Part of the energy is used for growth, reproduction, movement and other needs, and is not available for the next level.

Shorter food chains store more energy than longer ones. The spent energy is absorbed by the environment.

If you find an error, please highlight a piece of text and click Ctrl+Enter.