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

The concept of an ecosystem

There is such a science as ecology, which studies But these relationships can only be carried out within the framework of a certain ecosystem and occur not 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 environment through the exchange of matter, 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 which 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 the direct participation of a person. 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. Created by human hands, and can only exist with his participation. They are also divided into:

• Agroecosystems, that is, those associated with economic activity person.
• Technoecosystems appear in connection with the industrial activities of people.
• urban ecosystems.

Another classification distinguishes the following types of natural ecosystems:

1. Ground:

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

2. Freshwater ecosystems:

• stagnant reservoirs
• Flowing waters (rivers, streams).
• Swamps.

3. Marine ecosystems:

• Ocean.
• continental shelf.
• Fishing areas.
• Mouths of rivers, bays.
• Deep water rift zones.

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

Distinguishing features of an ecosystem

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

• In any ecosystem, the essential 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.

Whole the world It 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, their life forms, the biotic structure in any of them is still the same.

Any types of ecosystems include the same components; without their presence, the functioning of the system is simply impossible.

1. Producers.
2. Consumers of the second order.
3. Reducers.

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

Consumers include all organisms that need organic matter from outside to build their bodies. This includes all herbivorous organisms, predators and omnivores.

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

Functioning of ecosystems

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

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

If we talk about the exchange of energy, then it is quite possible to apply the laws of physics. The first law of thermodynamics states that energy does not disappear without a trace. It only changes from one species 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 activity due 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. Part of it, of course, is lost in the form of heat.

Whatever types of natural ecosystems exist, such laws operate absolutely in each.

Ecosystem structure

If we consider any ecosystem, then we can definitely see in it that various categories, for example, 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, then 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 the ecosystem, diversity ensures the stability of all processes that take place within the community.

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

Any structure in without fail present in any ecosystem, but it can vary significantly. For example, if we compare the biogeocenosis of the desert and the rainforest, the difference is visible to the naked eye.

artificial ecosystems

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

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

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 types of organisms can easily be created at home. If you put an aquarium, pour water into it, place a few branches of elodea and settle two fish, here you have an artificial system ready. Even such a simple one cannot exist without human intervention.

The value of ecosystems in nature

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

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

Any ecosystem is very easy to destroy, especially given the capabilities of man.

Ecosystems and man

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

By interfering with centuries-old ecosystems and violating the laws of the existence of organisms, man has led to the fact that all the ecologists of the world are already shouting with one voice that the world has come. Most scientists are sure that natural disasters, which in recent times began to occur more often, are the answer of nature to the thoughtless interference of man in its laws. It's time to stop and think that any kind of ecosystems were formed for centuries, long before the appearance of man, and perfectly existed without him. Can humanity live without nature? The answer suggests itself.

Ecosystems are one of the key concepts of ecology, which is a system that includes several components: a community of animals, plants and microorganisms, a characteristic habitat, a whole system of relationships through which the interchange of substances and energies is carried out.

In science, there are several classifications of ecosystems. One of them divides all known ecosystems into two large classes: natural, created by nature, and artificial, those created by man. Let's look at each of these classes in more detail.

natural ecosystems

As noted above, natural, natural ecosystems were formed as a result of the action of the forces of nature. They are characterized by:

• The close relationship between organic and inorganic substances
• A complete, vicious circle of the circulation of substances: starting from the appearance of organic matter and ending with its decay and decomposition into inorganic components.
• Resilience and ability to self-heal.

All natural ecosystems are defined by the following features:

• 1. species structure: the number of each species of animal or plant is regulated by natural conditions.
  2. Spatial structure: all organisms are arranged in a strict horizontal or vertical hierarchy. For example, in a forest ecosystem, tiers are clearly distinguished, in an aquatic ecosystem, the distribution of organisms depends on the depth of the water.
  3. Biotic and abiotic substances. The organisms that make up an ecosystem are divided into inorganic (abiotic: light, air, soil, wind, humidity, pressure) and organic (biotic - animals, plants).
  4. In turn, the biotic component is divided into producers, consumers and destroyers. Producers include plants and bacteria, which, with the help of sunlight and energy, create organic matter from inorganic substances. Consumers are animals and carnivorous plants that feed on this organic matter. Destroyers (fungi, bacteria, some microorganisms) are the crown of the food chain, as they produce the reverse process: organics are converted into inorganic substances.

The spatial boundaries of each natural ecosystem are very conditional. In science, it is customary to define these boundaries by the natural contours of the relief: for example, a swamp, lake, mountains, rivers. But in the aggregate, all the ecosystems that make up the bioenvelope of our planet are considered open, as they interact with the environment and space. In the very general idea the picture looks like this: living organisms receive energy, cosmic and terrestrial substances from the environment, and at the output - sedimentary rocks and gases that eventually escape into space.

All components of the natural ecosystem are closely interconnected. The principles of this connection are formed over the years, sometimes centuries. But that is why they become so stable, because these connections and climatic conditions and determine the species of animals and plants that live in this area. Any imbalance in the natural ecosystem can lead to its disappearance or attenuation. Such a violation can be, for example, deforestation, extermination of a population of a particular species of animals. In this case, the food chain is immediately disrupted, and the ecosystem begins to "fail".

By the way, the introduction of additional elements into ecosystems can also disrupt it. For example, if a person starts breeding animals in the selected ecosystem that were not there initially. A vivid confirmation of this is the breeding of rabbits in Australia. At first it was profitable, because in such a fertile environment and excellent climatic conditions for breeding, rabbits began to multiply with incredible speed. But in the end it all came crashing down. Countless hordes of rabbits devastated pastures where sheep used to graze. The number of sheep began to decline. A person receives much more food from one sheep than from 10 rabbits. This case even entered the proverb: "Rabbits ate Australia." It took an incredible effort of scientists and great expenses before they managed to get rid of the rabbit population. It was not possible to completely exterminate their population in Australia, but their numbers declined and no longer threatened the ecosystem.

artificial ecosystems

Artificial ecosystems are communities of animals and plants that live in conditions created for them by man. They are also called noobiogeocenoses or socioecosystems. Examples: field, pasture, city, society, spaceship, zoo, garden, artificial pond, reservoir.

by the most simple example artificial ecosystem is an aquarium. Here, the habitat is limited by the walls of the aquarium, the influx of energy, light and nutrients is carried out by man, he also regulates the temperature and composition of the water. The number of inhabitants is also initially determined.

First feature: all artificial ecosystems are heterotrophic, i.e. consuming prepared food. Take, for example, a city, one of the largest man-made ecosystems. The influx of artificially created energy (gas pipeline, electricity, food) plays a huge role here. At the same time, such ecosystems are characterized by a high yield of toxic substances. That is, those substances that in the natural ecosystem later serve for the production of organic matter often become unusable in artificial ones.

Another one distinguishing feature artificial ecosystems - an open cycle of metabolism. Take, for example, agro-ecosystems - the most important for humans. These include fields, orchards, vegetable gardens, pastures, farms and other agricultural lands on which a person creates conditions for the removal of consumer products. A part of the food chain in such ecosystems is taken out by a person (in the form of a crop), and therefore the food chain becomes destroyed.

The third difference between artificial ecosystems and natural ones is their species scarcity.. Indeed, a person creates an ecosystem for the sake of breeding one (rarely several) species of plants or animals. For example, in a wheat field, all pests and weeds are destroyed, only wheat is cultivated. This makes it possible to get the best harvest. But at the same time, the destruction of organisms "unprofitable" for humans makes the ecosystem unstable.

Comparative characteristics of natural and artificial ecosystems

It is more convenient to present a comparison of natural ecosystems and socio-ecosystems in the form of a table:

natural ecosystems	artificial ecosystems
The main component is solar energy.	Mainly gets energy from fuel and cooked food (heterotrophic)
Forms fertile soil	Depletes the soil
All natural ecosystems absorb carbon dioxide and produce oxygen.	Most artificial ecosystems consume oxygen and produce carbon dioxide.
Great species diversity	Limited number of species of organisms
High stability, ability to self-regulation and self-healing	Weak sustainability, as such an ecosystem depends on human activities
closed metabolism	Unclosed metabolic chain
Creates habitats for wild animals and plants	Destroys wildlife habitats
Accumulates water, using it wisely and purifying	High water consumption, its pollution

lesson type - combined

Methods: partially exploratory, problem presentation, reproductive, explanatory-illustrative.

Target:

Students' awareness of the importance of all the issues discussed, the ability to build their relationship with nature and society based on respect for life, for all living things as a unique and priceless part of the biosphere;

Tasks:

Educational: to show the multiplicity of factors acting on organisms in nature, the relativity of the concept of "harmful and beneficial factors", the diversity of life on planet Earth and the options for adapting living beings to the whole range of environmental conditions.

Developing: develop communication skills, the ability to independently acquire knowledge and stimulate their cognitive activity; the ability to analyze information, highlight the main thing in the studied material.

Educational:

To cultivate a culture of behavior in nature, the qualities of a tolerant person, to instill interest and love for wildlife, to form a stable positive attitude towards every living organism on Earth, to form the ability to see beauty.

Personal: cognitive interest in ecology. Understanding the need to gain knowledge about the diversity of biotic relationships in natural communities in order to preserve natural biocenoses. The ability to choose the target and semantic settings in their actions and deeds in relation to wildlife. The need for fair evaluation of one's own work and the work of classmates

cognitive: the ability to work with various sources of information, convert it from one form to another, compare and analyze information, draw conclusions, prepare messages and presentations.

Regulatory: the ability to organize independently the execution of tasks, evaluate the correctness of the work, reflection of their activities.

Communicative: participate in the dialogue in the classroom; answer questions from a teacher, classmates, speak to an audience using multimedia equipment or other means of demonstration

Planned results

Subject: know - the concepts of "habitat", "ecology", "environmental factors" their influence on living organisms, "connections of living and non-living";. Be able to - define the concept of "biotic factors"; characterize biotic factors, give examples.

Personal: make judgments, search and select information; analyze connections, compare, find an answer to a problematic question

Metasubject: links with such academic disciplines like biology, chemistry, physics, geography. Plan actions with a set goal; find the necessary information in the textbook and reference literature; to carry out the analysis of objects of nature; draw conclusions; formulate your own opinion.

Form of organization learning activities - individual, group

Teaching methods: visual and illustrative, explanatory and illustrative, partially exploratory, independent work with additional literature and textbook, with DER.

Receptions: analysis, synthesis, conclusion, transfer of information from one type to another, generalization.

Learning new material

Natural and artificial ecosystems

The term "ecosystem" is applicable to biocenoses and biotopes of various sizes. Can be distinguished:

microecosystems(for example, the trunk of a dead tree);

mesoecosystems(for example, a forest or a pond);

macroecosystems(for example, the ocean).

All of these are natural, ecosystems. As an example of a natural, relatively simple ecosystem, consider the ecosystem of a small pond.

Pond ecosystem can be represented in the form of several main components.

Abiotic component.

These are the main organic and inorganic compounds - water, carbon dioxide, oxygen, calcium salts, salts of nitric and phosphoric acids, amino acids, humic acids, as well as air and water temperature and its fluctuations in different time years, water density, pressure, etc.

Biotic component.

Producers.

In the pond, they are presented in the form of large plants, usually living only in shallow water, small floating plants (algae), called phytoplankton, and finally, bottom flora - phytobenthos, also represented mainly by algae. With an abundance of phytoplankton, the water acquires a greenish color.

Consumers.

This group includes animals (insect larvae, crustaceans, fish). Primary consumers (herbivores) feed directly on living plants or plant residues. They are divided into two types: zooplankton and zoobenthos. Secondary consumers (carnivores), such as predatory insects and predatory fish, feed on primary consumers or on each other.

Saprotrophs.

Aquatic bacteria, flagella and fungi are ubiquitous in the pond, but they are especially abundant at the bottom, on the border between water and silt, where dead plants and animals accumulate.

Natural ecosystems are quite complex, and it is very difficult to study them using the traditional scientific method of "experience and control". Therefore, environmental scientists use laboratory artificial microecosystems that simulate processes occurring in natural conditions. The next page shows two examples of laboratory microecosystems. Try to explain the mechanism of their functioning.

There is a misconception regarding "balance" in an aquarium. It is possible to achieve an approximate balance in the aquarium with regard to the gas and food regime only under the condition that there will be few fish in it, and a lot of water and plants. Back in 1857, J. Warrington established "this wonderful and delightful balance between the animal and vegetable kingdoms" in a 12 gallon (54.6 l) aquarium, settling in it several goldfish and snails. In addition, he planted a large number of perennial aquatic plants, Vallisneria, which serve as food for fish. J. Warrington correctly assessed not only the interaction of fish and plants, but also the importance of detritivorous snails "for the decomposition of plant remains and mucus", as a result of which "what could act as a poisonous principle turned into a fertile environment for plant growth. Most hobbyist attempts to balance the aquarium fail because too many fish are placed in the aquarium (an elementary case of overcrowding). Therefore, amateur aquarists have to periodically artificially maintain the balance in the aquarium (additional nutrition, aeration, periodic cleaning of the aquarium).

Distinguishopen and closed types of space ship.

In an open system (without regeneration), the flow of substances and energy goes in one direction, and the life of the system will depend on the supply of water, food and oxygen. Used materials and waste are stored on the spacecraft until they return to earth or are thrown into space (!).

In a system that is closed in all respects (except for energy), the circulation of substances occurs, which, like the flow of energy, can be regulated using external mechanisms. Today, almost all spaceships an open type system with different degrees of regeneration is used.

The basic concept that is studied by ecology. This is a science that studies all the relationships between living organisms and the environment. This includes the relationship of people and animals, people and plants, and also considers the treatment of mankind with the environment.

What is an ecosystem?

This term was first considered in 1935. It was proposed by A. Tensley, dividing the ecological system into several main components:

The exchange of substances between living organisms in the environment.

The community of all living organisms, which is called biocenosis.

Habitat - biotope.

All connections and types of connections between organisms in each individual habitat.

Each habitat has its own climatic, energy and biological features. It depends on them which organisms will live in one ecosystem.

The earth is considered one large ecosystem, which is divided into subspecies - various environments a habitat. The most important source of energy for it is the sun.

In all artificial ecosystems, the consumers are the organisms that live there.

artificial ecosystems

Let's first understand what an artificial habitat is. This is an ecosystem that was created by man. The main consumers in artificial ecosystems are living organisms that have been placed there.

If you ask any person about an artificial ecosystem, then the thought of a home aquarium immediately comes to mind. Although it is not a large habitat, it belongs to artificial ecosystems created by man.

It is rather limited, and all its internal conditions are regulated by the owner. He independently chooses what nutrients the aquarium fish will receive. In addition, he adjusts the light, temperature, regulates the main components of the water, and also selects the plants that will grow inside the aquarium.

Main types of artificial ecosystems

In the 21st century, everywhere you look, there is an artificial habitat everywhere. For example, the aquarium, which we wrote about above.

Types of ecosystems:

Field. This can be attributed to the usual wheat field. The difference from an aquarium is that the main energy for living organisms is the sun, which is not subject to human control. However, people themselves choose which plants will grow on the field, what they will fertilize, and also what they will eat.

Pasture. Very similar to a field, as solar energy is also an important input for livestock. The difference from the field is that the main living organisms are animals, not plants. A person chooses what they will eat. He can grow certain nutritious plants in the pasture, but this is already a hybrid of field and pasture.

City. One of the main ecosystems of mankind. All settlements are artificial ecosystems, the main consumer is man. Again, the energy of the sun is the only thing that is not subject to it. The rest is his job, from food to electricity.

Features of artificial ecosystems

The main difference is heterotrophy. That is, all the main consumers of artificial ecosystems eat pre-cooked food.

In addition, all food chains in artificial ecosystems are destroyed. For example, a garden. The man himself harvests, not allowing insects and other types of pests to eat. This leads to the destruction of the food chain.

The difference between artificial ecosystems and natural ones

There are quite a few differences. The first is that in natural ecosystems, all the nutrients for living organisms are provided by wildlife.

Also, in artificial ecosystems, the main consumers are much smaller than in natural ones. This is due to the fact that people plant only one, sometimes several types of plants in the fields. Only certain types of animals are bred on their pastures.

In addition, not all representatives of the animal world are suitable for life in an artificial habitat.

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 a rise in temperature) 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.

Typically, 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 tropical forest). 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 that have 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 areas are a haven for various kinds 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

An aquatic ecosystem is an ecosystem located in 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 total world water reserves. 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 typically contain a higher concentration of dissolved oxygen, thereby supporting more biodiversity than stagnant water 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 high percentage water, up to 90% or even 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 food, and are released into the environment simple substances(inorganic and organic) 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 interacts with the 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 on certain territory, at this point in time. It may contain populations of living organisms of different species. 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.