Environmental problems are currently among the most pressing and priority on the planet. Much attention is paid to how people use lake ecosystems and forests. Behind great science lie terms that today not only schoolchildren, but also every self-respecting adult should know. We often hear "ecosystem pollution", what does this mean? What parts does an ecosystem consist of? The basics of discipline are taught already in elementary school. As an example, we can highlight the topic “Forest Ecosystem” (grade 3).

Why did ecology emerge as a science?

This is a relatively young biological discipline that emerged as a result of the rapid development of human labor activity. Intensified use of natural resources has led to disharmony between people and the surrounding world. The term "ecology", proposed by E. Haeckel in 1866, is literally translated from Greek as "the science of home, habitat, shelter." In other words, this is the doctrine of the relationship between living organisms and their environment.

Ecology, like any other science, did not arise immediately. It took almost 70 years for the concept of “ecosystem” to emerge.

Stages of development of science and first terms

In the 19th century, scientists accumulated knowledge, described environmental processes, generalized and systematized existing materials. The first naki terms began to appear. For example, K. Mobius proposed the concept of “biocenosis”. It is understood as a collection of living organisms that exist in the same conditions.

At the next stage of development of science, the main measuring category is identified - the ecosystem (A. J. Tansley in 1935 and R. Linderman in 1942). Scientists have been studying energy and trophic (nutrient) metabolic processes at the level of living and non-living components of the ecosystem.

At the third stage, the interaction of various ecosystems was analyzed. Then they were all combined into such a concept as the biosphere.

In recent years, science has mainly focused on the interaction of humans with the environment, as well as the destructive influence of anthropogenic factors.

What is an ecosystem?

This is a complex of living beings with their habitat, which is functionally united into a single whole. There is necessarily interdependence between these environmental components. There is a connection between living organisms and their environment at the level of substances, energy and information.

The term was first proposed in 1935 by the British botanist A. Tansley. He also determined what parts the ecosystem consists of. Russian biologist V.N. Sukachev introduced the concept of “biogeocenosis” (1944), which is less voluminous in relation to the ecosystem. Variants of biogeocenoses can be a spruce forest or a swamp. - ocean, Volga river.

All living organisms can be influenced by biotic, abiotic and anthropogenic environmental factors. For example:

• a frog ate a mosquito (biotic factor);
• a person gets wet in the rain (abiotic factor);
• people cut down the forest (anthropogenic factor).

Components

What parts does an ecosystem consist of? There are two main components or parts of an ecosystem - biotope and biocenosis. A biotope is a place or territory in which a living community (biocenosis) lives.

The concept of biotope includes not only the habitat itself (for example, soil or water), but also abiotic (non-living) factors. These include climatic conditions, temperature, humidity, etc.

Structure

Each one has a specific structure. It is characterized by the presence of certain varieties of living organisms that can comfortably exist in this environment. For example, the stag beetle lives in mountainous areas.

All types of living organisms are distributed in an ecosystem in a structured way: horizontally or vertically. The vertical structure is represented by plant organisms, which, depending on the amount of solar energy they need, are built into tiers or floors.

Often, in tests, schoolchildren are given the task of distributing floors in a forest ecosystem (grade 3). The lower floor is the litter (basement), which is formed by fallen leaves, pine needles, dead organisms, etc. The next tier (ground) is occupied by mosses, lichens, and mushrooms. A little higher there is grass; by the way, in some forests this floor may not exist. Next comes a layer of bushes and young tree shoots, followed by small trees, and the topmost floor is occupied by large, tall trees.

The horizontal structure represents a mosaic arrangement of different types of organisms or microgroups depending on their food chains.

Important Features

Living organisms inhabiting a certain one feed on each other in order to preserve their vital functions. This is how food or trophic chains of an ecosystem are formed, which consist of links.

The first link includes producers or organisms that produce (produce), synthesize organic substances from inorganic ones. For example, a plant consumes carbon dioxide and releases oxygen and glucose, an organic compound, during photosynthesis.

The intermediate link is decomposers (saprotrophs or decomposers). These include organisms that are capable of decomposing the remains of non-living plants or animals. As a result, the transformation of organic matter into inorganic occurs. Reducers are microscopic fungi and bacteria.

The third link is represented by the group of consumers (consumers or heterotrophs), which includes humans. These living beings cannot synthesize organic compounds from inorganic ones, so they receive them in finished form from the environment. These include herbivorous organisms (cow, hare, etc.), the subsequent orders include carnivorous predators (tiger, lynx, lion), omnivores (bear, human).

Types of ecosystems

Any ecological system is open. It can also exist in an isolated form, its boundaries are blurred. Depending on the size, very small or microecological systems (human oral cavity), medium or mesoecological systems (forest edge, bay) and macroecological systems (ocean, Africa) are distinguished.

Depending on the method of origin, ecosystems are classified as spontaneously created or natural and artificial or man-made. Examples of ecosystems of natural formation: sea, stream; artificial - pond.

Based on their location in space, they distinguish between aquatic (puddle, ocean) and terrestrial (tundra, taiga, forest-steppe) ecological systems. The former, in turn, are divided into marine and freshwater. Freshwater can be lotic (stream or river), lentic (reservoir, lake, pond) and wetland (swamp).

Examples of ecosystems and their use by humans

Humans can have an anthropogenic effect on the ecosystem. Any use of nature by humans has an impact on the ecological system at the regional, national or planetary level.

As a result of excessive grazing, irrational environmental management and deforestation, two meso-ecosystems (field, forest) are destroyed at once, and in their place an anthropogenic desert is formed. Unfortunately, there are many such examples of ecosystems that can be cited.

How people use lake ecosystems is important on a regional scale. For example, with thermal pollution as a result of the discharge of heated water into a lake, it becomes swamped. Living creatures (fish, frogs, etc.) die, blue-green algae actively reproduce. The world's main supply of fresh water is concentrated in lakes. Consequently, pollution of these water bodies leads to disruption not only regional, but also the global ecosystem of the world.

From an ecosystem perspective, a lake, forest or some other element of nature seems to us to consist of two main components: autotrophic component(autotrophic means self-feeding), capable of capturing light energy and using simple inorganic substances for food, and gerotrophic component(heterotrophic means feeding on ready-made organic substances), which decomposes, rearranges and uses complex substances synthesized by autotrophic organisms.

These functional components are arranged in overlapping layers, with the largest number of autotrophic organisms located in the upper layer, where light energy enters, while intense heterotrophic activity is concentrated in places where organic matter accumulates in the soil and silt.

From the point of view of structure, it is convenient to distinguish four components of the ecosystem: 1) abiotic substances - the main elements and components of the environment; 2) producers - producers, autotrophic elements (mainly green plants); 3) large consumers, or macroconsumers, - heterotrophic organisms (mainly animals that devour other organisms or grind organic matter); 4) decomposers, or microconsumers (also called saprophytes or saprobic organisms), heterotrophic organisms (mainly bacteria and fungi) that decompose the complex components of dead protoplasm, absorb decay products and release simple substances used by producers.

These ecosystems are the most extreme types found in the biosphere; they strongly highlight the similarities and differences of all ecosystems. A terrestrial ecosystem (represented by a field, depicted on the left) and an open aquatic system (represented by either a lake or sea, depicted on the right) are inhabited by completely different organisms, with the possible exception of some bacteria that can live in both environments.

Despite this, basic ecological components are present and active in both types of ecosystems. On land, autotrophs are usually represented by large plants with roots; whereas in deep reservoirs the role of autotrophs is taken over by microscopic plants suspended in water, called phytoplankton(phyton - plant; plankton - suspended). Given a certain amount of light and minerals over a certain period of time, the smallest plants can produce the same amount of food as large plants. Both types of producers provide life to the same number of consumers and decomposers. In the future, the similarities and differences between land and aquatic ecosystems will be examined in more detail.

In order to understand the relationship between structure and function, it is necessary to evaluate the structure of the ecosystem from different points of view. The connection between producers and consumers is one type of structure called trophic(trophe - nutrition), and each “food” level is called a trophic level. The amount of living material at different trophic levels or in a population is called the “yield of a field,” a term that applies equally to plants and animals. “Crop in the field” can be expressed either by the number of organisms per unit area, or by the amount of biomass, i.e. body weight of organisms (live weight, dry weight, dry weight without ash residue, carbon weight, number of calories), or in some or other units suitable for comparison purposes. The "crop in the field" not only represents potential energy, but plays a large role in reducing fluctuations in physical conditions, and also as a habitat, or living space, for organisms. Thus, trees in a forest not only act as energy reserves that provide food or fuel, but they also change the climate and provide refuges for birds and people.

The amount of lifeless material, such as phosphorus, nitrogen, etc., available at a given time may be considered a state of stability, or a stable quantity. It is necessary to distinguish between the quantities of materials and organisms available at one time or another on average over a certain period, and the rate of change in the state of stability and “harvest in the field” per unit of time. The functions of changing speeds will be discussed in detail after becoming familiar with some other aspects of ecosystem structure.

The amount and distribution of both inorganic and organic substances concentrated either in the biomass or in the environment should be considered an important characteristic of any ecosystem. We could talk about this in general terms as a biochemical structure. For example, knowledge of the amount of chlorophyll per unit of land or water surface is of great ecological interest. It is also extremely important to know the amount of organic matter dissolved in the water. In addition, it is necessary to represent the species structure of the ecosystem. The ecological structure reflects not only the number of certain species, but also the species diversity of the ecosystem. The latter manifests itself in the form of relationships between species and the number of individuals or biomass and in the form of dispersion (spatial distribution) of individuals of all species that make up the community.

It should be emphasized that ecosystems can be limited to different sizes. The objects of research can be a small pond, a large lake, a plot of forest, or even a small aquarium. Any unit can be considered an ecosystem if it contains leading and interacting components that create functional stability at least for a short time. Our biosphere as a whole is a series of transitions - gradients (from mountains to valleys, from coasts to the depths of the sea, etc.), which together create a “chemostat”, namely the constancy of the chemical composition of air and water over a long period of time. It is not particularly important where to draw the boundaries between the gradients, since the ecosystem is primarily a functional unity. It must, of course, be pointed out that in nature there are often discontinuities in gradients that provide convenient and functionally logical boundaries. Thus, for example, the shore of a lake can be understood as the proper boundary between two sharply different ecosystems, namely the lake and the forest. The larger and more diverse the ecosystem, the more stable it is and relatively independent of the actions of adjacent systems. Thus, the entire lake can be considered as a more independent unit than part of the lake, but for the purposes of the study, even a separate part of the lake can be considered an ecosystem.

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

All living organisms live on Earth not in isolation from each other, but forming communities. Everything in them is interconnected, both living organisms and Such a formation in nature is called an ecosystem, which lives according to its own specific laws and has specific characteristics and qualities that we will try to get acquainted with.

Ecosystem concept

There is such a science as ecology, which studies But these relationships can only be carried out within a certain ecosystem and do not occur spontaneously and chaotically, but according to certain laws.

There are different types of ecosystems, but they are all a collection of living organisms that interact with each other and with the environment through the exchange of substances, energy and information. That is why the ecosystem remains stable and sustainable over a long period of time.

Ecosystem classification

Despite the great diversity of ecosystems, they are all open; without this, their existence would be impossible. The types of ecosystems are different, and the classification may be different. If we keep in mind the origin, then ecosystems are:

1. Natural or natural. In them, all interaction is carried out without direct human participation. They in turn are divided into:

• Ecosystems that are completely dependent on solar energy.
• Systems that receive energy from both the sun and other sources.

2. Artificial ecosystems. They are created by human hands, and can only exist with his participation. They are also divided into:

• Agroecosystems, that is, those that are associated with human economic activities.
• Technoecosystems appear in connection with the industrial activities of people.
• Urban ecosystems.

Another classification identifies the following types of natural ecosystems:

1. Ground:

• Rainforests.
• Desert with grassy and shrubby vegetation.
• Savannah.
• Steppes.
• Deciduous forest.
• Tundra.

2. Freshwater ecosystems:

• Stagnant bodies of water
• Flowing waters (rivers, streams).
• Swamps.

3. Marine ecosystems:

• Ocean.
• Continental shelf.
• Fishing areas.
• River mouths, bays.
• Deep-sea rift zones.

Regardless of the classification, one can see the diversity of ecosystem species, which is characterized by its own set of life forms and numerical composition.

Distinctive features of an ecosystem

The concept of ecosystem can be attributed to both natural formations and artificially created ones. If we talk about natural ones, then they are characterized by the following signs:

• In any ecosystem, the required elements are living organisms and abiotic environmental factors.
• In any ecosystem there is a closed cycle from the production of organic substances to their decomposition into inorganic components.
• The interaction of species in ecosystems ensures stability and self-regulation.

The entire surrounding world is represented by various ecosystems, which are based on living matter with a certain structure.

Biotic structure of an ecosystem

Even if ecosystems differ in species diversity, abundance of living organisms, and their life forms, the biotic structure in any of them is still the same.

Any type of ecosystem includes the same components; without their presence, the functioning of the system is simply impossible.

1. Producers.
2. Second-order consumers.
3. Decomposers.

The first group of organisms includes all plants that are capable of photosynthesis. They produce organic substances. This group also includes chemotrophs, which form organic compounds. But for this purpose they do not use solar energy, but the energy of chemical compounds.

Consumers include all organisms that require the supply of organic substances from the outside to build their bodies. This includes all herbivorous organisms, predators and omnivores.

Reducers, which include bacteria and fungi, transform the remains of plants and animals into inorganic compounds suitable for use by living organisms.

Ecosystem functioning

The largest biological system is the biosphere; it, in turn, consists of individual components. You can make the following chain: species-population - ecosystem. The smallest unit included in ecosystems is a species. In each biogeocenosis, their number can vary from several tens to hundreds and thousands.

Regardless of the number of individuals and individual species in any ecosystem, there is a constant exchange of matter and energy not only among themselves, but also with the environment.

If we talk about the exchange of energy, then the laws of physics can be applied here. The first law of thermodynamics states that energy does not disappear without a trace. It just changes from one type to another. According to the second law, in a closed system energy can only increase.

If physical laws are applied to ecosystems, then we can come to the conclusion that they support their vital functions thanks to the presence of solar energy, which organisms are able not only to capture, but also to transform, use, and then release into the environment.

Energy is transferred from one trophic level to another; during the transfer, one type of energy is converted into another. Some of it, of course, is lost in the form of heat.

Whatever types of natural ecosystems exist, such laws apply in absolutely every one.

Ecosystem structure

If you consider any ecosystem, you will definitely see that various categories, such as producers, consumers and decomposers, are always represented by a whole set of species. Nature provides that if something suddenly happens to one of the species, the ecosystem will not die from this; it can always be successfully replaced by another. This explains the stability of natural ecosystems.

A large variety of species in an ecosystem, diversity ensures the stability of all processes that occur within the community.

In addition, any system has its own laws, which all living organisms obey. Based on this, we can distinguish several structures within the biogeocenosis:

Any structure is necessarily present in any ecosystem, but it can differ significantly. For example, if you compare the biogeocenosis of a desert and a tropical forest, the difference is visible to the naked eye.

Artificial ecosystems

Such systems are created by human hands. Despite the fact that they, like natural ones, necessarily contain all the components of the biotic structure, there are still significant differences. Among them are the following:

1. Agrocenoses are characterized by a poor species composition. Only those plants that humans grow grow there. But nature takes its toll, and you can always, for example, see cornflowers, daisies, and various arthropods in a wheat field. In some systems, even birds manage to build a nest on the ground and raise their chicks.
2. If people do not take care of this ecosystem, then cultivated plants will not be able to withstand competition with their wild relatives.
3. Agrocenoses also exist due to the additional energy that humans bring, for example, by applying fertilizers.
4. Since the grown plant biomass is removed along with the harvest, the soil is depleted of nutrients. Therefore, for further existence, human intervention is again necessary, who will have to apply fertilizers in order to grow the next crop.

It can be concluded that artificial ecosystems do not belong to sustainable and self-regulating systems. If a person stops caring for them, they will not survive. Gradually, wild species will displace cultivated plants, and the agrocenosis will be destroyed.

For example, an artificial ecosystem of three species of organisms can easily be created at home. If you set up an aquarium, fill it with water, place a few sprigs of elodea and add two fish, your artificial system is ready. Even something as simple as this cannot exist without human intervention.

The importance of ecosystems in nature

Speaking globally, all living organisms are distributed across ecosystems, so their importance is difficult to underestimate.

1. All ecosystems are interconnected by the cycle of substances that can migrate from one system to another.
2. Thanks to the presence of ecosystems, biological diversity is preserved in nature.
3. All the resources that we draw from nature are given to us by ecosystems: clean water, air,

It is very easy to destroy any ecosystem, especially considering human capabilities.

Ecosystems and people

Since the advent of man, his influence on nature has increased every year. Developing, man imagined himself to be the king of nature, and without hesitation began to destroy plants and animals, destroy natural ecosystems, thereby beginning to chop down the branch on which he himself sits.

By interfering with age-old ecosystems and violating the laws of existence of organisms, man has led to the fact that all the ecologists of the world are shouting with one voice that the world has come. Most scientists are confident that natural disasters, which have recently begun to occur more and more often, are nature’s response to thoughtless human intervention in its laws. It's time to stop and think that all types of ecosystems were formed over centuries, long before the advent of man, and existed perfectly well without him. But can humanity live without nature? The answer suggests itself.

Community- this is a collection of certain living organisms, for example, the plant community of the steppe.

Ecosystem (biocenosis) is a set of living organisms and their habitat, characterized by the cycle of substances and the flow of energy (pond, meadow, forest).

Biogeocenosis- an ecosystem located in a specific area of ​​land and inextricably linked with this specific area. (Temporary, artificial and aquatic ecosystems are not considered biogeocenoses.)

Processes in ecosystems

Cycle of substances in the ecosystem occurs through food chains: producers take inorganic substances from inanimate nature and make organic substances from them; at the end of the food chain, decomposers do the opposite.

Energy flow: most ecosystems receive energy from the sun. Plants store it in organic matter during photosynthesis. This energy is used for the life of all other organisms in the ecosystem. Passing through food chains, this energy is gradually consumed (10% rule), and in the end all solar energy absorbed by producers is converted into heat.

Self-regulation- the main property of ecosystems: due to biotic connections, the number of all species is maintained at a constant level. Self-regulation allows ecosystems to withstand adverse impacts. For example, a forest can survive (recover) after several years of drought, rapid reproduction of cockchafers and/or hares.

Ecosystem sustainability. The more species there are in an ecosystem, the more food chains there are, and the more stable (balanced) the cycle of substances and the ecosystem itself are. If the number of species (biological diversity) decreases, the ecosystem becomes unstable and loses the ability to self-regulate.

Change of ecosystem (succession). An ecosystem that produces more organic matter than it consumes is unsustainable. She overgrown, this is a normal process of self-development of an ecosystem (living organisms themselves change their habitat). For example, a forest pond turns into a swamp, a steppe into a forest-steppe, a birch forest into an oak grove, etc. External influences, such as fire or deforestation, can also lead to a change in ecosystem. All these were examples of secondary succession; the primary one occurs in a lifeless area.

Choose one, the most correct option. Thanks to self-regulation in the ecosystem
1) no species is completely destroyed by another species
2) population numbers are constantly declining
3) there is a circulation of substances
4) organisms reproduce

Answer

Choose one, the most correct option. The main reason for the instability of ecosystems is
1) fluctuations in ambient temperature
2) lack of food resources
3) imbalance in the circulation of substances
4) increased abundance of some species

Answer

Choose one, the most correct option. The circulation of oxygen between various inorganic objects of nature and communities of living organisms is called
1) population waves
2) self-regulation
3) gas exchange
4) the cycle of substances

Answer

Choose one, the most correct option. An example of a biocenosis is a collection
1) trees and shrubs in the park
2) plants grown in a botanical garden
3) birds and mammals living in the spruce forest
4) organisms living in the swamp

Answer

Choose one, the most correct option. One of the factors maintaining balance in the biosphere
1) diversity of species and relationships between them
2) adaptability to the environment
3) seasonal changes in nature
4) natural selection

Answer

ECOSYSTEM SIGNS
1. Choose three options. What are the essential features of an ecosystem?
1) high number of consumer species of the third order
2) the presence of a circulation of substances and energy flow
3) seasonal changes in temperature and humidity
4) uneven distribution of individuals of the same species
5) the presence of producers, consumers and destroyers
6) relationship between abiotic and biotic components

Answer

2. Choose three correct answers out of six and write down the numbers under which they are indicated. Biogeocenoses are characterized
1) complex food chains
2) simple food chains
3) lack of species diversity
4) the presence of natural selection
5) dependence on human activity
6) steady state

Answer

3. Choose three correct answers out of six and write down the numbers under which they are indicated. The biogeocenosis of a river's fresh water body is characterized by
1) the presence of producers of organic matter - autotrophs
2) the absence of organic destroyers - decomposers
3) the presence of flowering plants in shallow waters
4) absence of predatory fish
5) the constant number of animal populations inhabiting it

Answer

4. Choose three correct answers out of six and write down the numbers under which they are indicated. In a broad-leaved forest ecosystem - oak grove
1) short food chains
2) sustainability is ensured by the diversity of organisms
3) the initial link of the food chain is represented by plants
4) the population composition of animals does not change over time
5) source of primary energy - sunlight
6) there are no decomposers in the soil

Answer

CYCLE
Choose three correct answers out of six and write down the numbers under which they are indicated. The cycle of substances in the ecosystem ensures
1) its stability
2) repeated use of the same chemical elements by organisms
3) seasonal and daily changes in nature
4) accumulation of peat
5) continuity of life
6) speciation

Answer

SELF-REGULATION
Choose three correct answers out of six and write down the numbers under which they are indicated. Self-regulation in natural ecosystems is manifested in the fact that
1) populations of first-order consumers are completely destroyed by third-order consumers
2) third-order consumers perform a sanitary role and regulate the number of first-order consumers
3) mass reproduction of first-order consumers leads to mass death of producers
4) the number of producers is reduced as a result of the action of abiotic environmental factors
5) the number of first-order consumers depends on the number of producers
6) the number of first-order consumers is regulated by second-order consumers

Answer

Establish the sequence of events characterizing self-regulation in biogeocenosis. Write down the corresponding sequence of numbers
1) a surge in the number of herbivores
2) high feed yield
3) return to normal numbers of predators and herbivores
4) increase in the number of predators
5) drop in the number of herbivores
6) slowing down the reproduction of predators

Answer

SUSTAINABILITY
1. Choose three options. Ecosystem sustainability is ensured
1) variety of types and food chains
2) closed cycle of substances
3) high numbers of individual species
4) fluctuations in the number of species
5) self-regulation
6) short power circuits

Answer

2. Choose three correct answers out of six and write down the numbers under which they are indicated. What signs indicate the stability of biogeocenosis?
1) species diversity
2) relief
3) climate
4) closed cycle
5) branched food chains
6) number of energy sources

Answer

3. Choose three correct answers out of six and write down the numbers under which they are indicated. The sustainability of the equatorial rainforest ecosystem is determined by
1) great species diversity
2) absence of decomposers
3) a large number of predators
4) branched food networks
5) fluctuations in population numbers
6) closed cycle of substances

Answer

4. Choose three correct answers out of six and write down the numbers under which they are indicated. What characteristics ensure the sustainability of a natural ecosystem?
1) high number of individuals of functional groups of organisms
2) balance of the cycle of substances
3) short food chains
4) self-regulation
5) reduction of energy in the food chain
6) application of mineral fertilizers

Answer

5. Choose three correct answers out of six and write down the numbers under which they are indicated. The sustainability of the equatorial moist forest is determined by
1) balanced circulation of substances
2) the ability to self-regulate
3) rich species diversity of organisms
4) dominance of tree forms in the phytocenosis
5) high air humidity
6) lack of a clear change of seasons

Answer

SUCCESSION EXAMPLES
1. Choose three correct answers out of six and write down the numbers under which they are indicated. Examples of natural change of ecosystems in the process of community development are
1) swamping of floodplain meadows after the construction of hydraulic structures
2) the formation of farmland on site from a plowed area of ​​the steppe
3) overgrowing of rocks with lichens
4) overgrowing of the pond and formation of a swamp
5) the formation of burning in a forest site as a result of a fire from an unextinguished cigarette
6) change of birch forest to spruce forest

Answer

2. Choose three correct answers out of six and write down the numbers under which they are indicated. From the list given, select examples that illustrate succession.

2) acclimatization of introduced cultivated plants
3) development of small-leaved forest in place of a grass-shrub community
4) movement of salmon fish to the spawning site
5) overgrowing of the volcano slope with lichens
6) establishing a tea plantation on the slopes of the mountain

Answer

PRIMARY SUCCESSION
1. Choose three correct answers out of six and write down the numbers under which they are indicated. Primary succession is characterized by:
1) begins after deforestation
2) a biogeocenosis is formed in a sand quarry
3) starts on rich soils
4) the soil takes a long time to form
5) crustose lichens settle on stones
6) felling turns into forest

Answer

2. Choose three correct answers out of six and write down the numbers under which they are indicated. Give examples of the initial stages of primary succession.
1) the formation of a swamp in place of a stagnant body of water
2) development of small-leaved forest at the site of felling
3) overgrowing of the volcano slope with lichens
4) formation of soil on rock
5) colonization of the rocky seashore by lichens
6) overgrowing of the fire with grasses

Answer

SUCCESSION PRIMARY SEQUENCE
1. Establish the sequence of processes that occur during the overgrowing of rocks
1) bare rocks
2) overgrowing with mosses
3) colonization by lichen
4) formation of a thin layer of soil
5) formation of herbaceous community

Answer

2. Establish the sequence of processes occurring during the change of biogeocenoses (succession)
1) colonization by shrubs
2) colonization of bare rocks by lichens
3) creating a sustainable community
4) germination of seeds of herbaceous plants
5) colonization of the territory with mosses

Answer

3. Establish the sequence of succession processes. Write down the corresponding sequence of numbers.
1) formation of soil as a result of erosion of the parent rock and the death of lichens
2) formation of an extensive power network
3) germination of seeds of herbaceous plants
4) colonization of the territory with mosses

Answer

4. Establish the sequence of appearance and development of ecosystems on bare rocks. Write down the corresponding sequence of numbers.
1) crustose lichens and bacteria
2) herbaceous-shrub community
3) forest community
4) herbaceous flowering plants
5) mosses and fruticose lichens

Answer

5. Establish the sequence of events that occur when living organisms colonize new lifeless territories. Write down the corresponding sequence of numbers.
1) colonization of mosses and fruticose lichens
2) the appearance of herbaceous plants and shrubs
3) the emergence of forest communities
4) the formation of a thin layer of soil
5) the appearance of bacteria, algae and crustose lichens
6) weathering of rocks

Answer

SECONDARY SUCCESSION
1. Establish the sequence of stages of restoration of a spruce forest after a fire. Write down the corresponding sequence of numbers.
1) the appearance of shrubs and deciduous trees
2) overgrowth of the fire with light-loving herbaceous plants
3) development of young spruce trees under the canopy of deciduous trees
4) formation of small-leaved forest
5) formation of the upper tier by mature spruce trees

Answer

2. Establish the sequence of secondary succession processes after cutting down a spruce forest damaged by the typograph beetle. Write down the corresponding sequence of numbers.
1) growth of shrubs with birch and aspen undergrowth
2) formation of a spruce forest
3) development of deciduous forest with spruce undergrowth
4) overgrowing of clearings with perennial light-loving grasses
5) formation of mixed forest

Answer

3. Establish the sequence of ecosystem changes during secondary succession. Write down the corresponding sequence of numbers.
1) swamp
2) deciduous forest
3) mixed forest
4) lake
5) coniferous forest
6) meadow

Answer

SUCCESSION PRIMARY - SECONDARY
Establish a correspondence between the examples and types of succession: 1) primary, 2) secondary. Write numbers 1 and 2 in the order corresponding to the letters.
A) proceeds quickly
B) forest restoration after a fire
B) proceeds slowly
D) develops after a disturbance of the biocenosis
D) development of territories where no living beings previously existed

Answer

==========================
Below is a list of terms. All of them, except two, are used to describe environmental patterns. Find two terms that “fall out” from the general series and write down the numbers under which they are indicated.
1) parthenogenesis
2) symbiosis
3) succession
4) aromorphosis
5) consumer

Answer

© D.V. Pozdnyakov, 2009-2019

There are various ecosystems on our planet. Ecosystem types are classified in a certain way. However, it is impossible to connect together all the diversity of these units of the biosphere. That is why there are several classifications of ecological systems. For example, they are distinguished by origin. This:

Natural (natural) ecosystems. These include those complexes in which the circulation of substances occurs without any human intervention.

Artificial (anthropogenic) ecosystems. They are created by man and are able to exist only with his direct support.

Ecological system (ecosystem)– a spatially defined set of living organisms and their habitat, united by material-energy and information interactions.

There are aquatic and terrestrial natural ecosystems.

Aquatic ecosystems These are rivers, lakes, ponds, swamps - freshwater ecosystems, as well as seas and oceans - bodies of salt water.

Terrestrial ecosystems– these are tundra, taiga, forest, forest-steppe, steppe, semi-desert, desert, mountain ecosystems.

Each terrestrial ecosystem has an abiotic component - a biotope, or ecotope - an area with the same landscape, climatic, and soil conditions; and the biotic component - community, or biocenosis - the totality of all living organisms inhabiting a given biotope. A biotope is a common habitat for all members of the community. Biocenoses consist of representatives of many species of plants, animals and microorganisms. Almost every species in the biocenosis is represented by many individuals of different sexes and ages. They form a population of a given species in an ecosystem. It is very difficult to consider a biocenosis separately from a biotope, so a concept such as biogeocenosis (biotope + biocenosis) is introduced. Biogeocenosis is an elementary terrestrial ecosystem, the main form of existence of natural ecosystems.

Each ecosystem includes groups of organisms of different species, distinguished by the way they feed:

Autotrophs (“self-feeding”);

Heterotrophs (“feeding on others”);

Consumers are consumers of organic matter of living organisms;

Ditritophages, or saprophages, are organisms that feed on dead organic matter - the remains of plants and animals;

Reducers - bacteria and lower fungi - complete the destructive work of consumers and saprophages, bringing the decomposition of organic matter to its complete mineralization and returning the last portions of carbon dioxide, water and mineral elements to the ecosystem environment.

All of these groups of organisms in any ecosystem closely interact with each other, coordinating the flows of matter and energy.

Thus , a natural ecosystem is characterized by three features:

1) an ecosystem is necessarily a collection of living and nonliving components.

2) within the ecosystem, a full cycle is carried out, starting with the creation of organic matter and ending with its decomposition into inorganic components.

3) the ecosystem remains stable for some time, which is ensured by a certain structure of biotic and abiotic components.

Examples of natural ecosystems are: a fallen tree, the corpse of an animal, a small body of water, a lake, a forest, a desert, tundra, land, ocean, biosphere.

As can be seen from the examples, simpler ecosystems are included in more complexly organized ones. At the same time, a hierarchy of organization of systems, in this case environmental, is realized. Therefore, ecosystems are divided according to spatial scale into microecosystems, mesoecosystems and macroecosystems.

Thus, the structure of nature should be considered as a systemic whole, consisting of ecosystems nested within one another, the highest of which is a unique global ecosystem - the biosphere. Within its framework, energy and matter are exchanged between all living and nonliving components on a planetary scale.