Types of ecosystems. General characteristics of ecosystems

*The term "ecosystem" is applicable to biocenoses and biotopes of various sizes, for example, the trunk of a dead tree, a forest or a pond, an ocean. All of these are natural ecosystems. As an example of a natural, relatively simple ecosystem, consider an ecosystem small pond. The pond ecosystem can be thought of as two main components.

**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.

Aquarium as an artificial ecosystem

There is a misconception regarding "balance" in an aquarium. It is possible to achieve an approximate balance in the aquarium in terms of gas and food regimes only on 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 a few goldfish and snails. In addition, he planted a large number of perennial aquatic plants vallisneria, serving 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).

***Maybe, The best way to imagine an artificial ecosystem is to think about space travel, since a person, leaving the biosphere, must take with him a clearly defined system that would provide all his vital needs, using sunlight as energy coming from the surrounding space environment.

Spaceship as an artificial ecosystem

Distinguish between open and closed types of spacecraft.

IN open system (without regeneration) the flow of matter 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 closed according to all parameters (except energy), the system undergoes a circulation of substances, which, like the energy flow, can be regulated using external mechanisms. Today, almost all spaceships system is used open type with different degrees of regeneration.

Unlike a natural ecosystem, an artificial ecosystem is characterized. Write your answer in numbers without spaces.

1) a wide variety of species

2) diverse supply chains

3) open circulation of substances

4) the predominance of one or two species

5) the influence of the anthropogenic factor

6) closed circulation of substances

Explanation.

Differences of agrocenoses from natural biogeocenoses. Between natural and artificial biogeocenoses, along with similarities, there are also big differences that are important to take into account in agricultural practice.

The first difference is in the different direction of selection. In natural ecosystems, there is natural selection that rejects non-competitive species and forms of organisms and their communities in the ecosystem and thereby ensures its main property - sustainability. In agrocenoses, mainly artificial selection operates, directed by man primarily to maximize the yield of agricultural crops. For this reason, the ecological stability of agrocenoses is low. They are not capable of self-regulation and self-renewal, they are subject to the threat of death during the mass reproduction of pests or pathogens. Therefore, without the participation of a person, his tireless attention and active intervention in their lives, agrocenoses of grain and vegetable crops exist for no more than a year, perennial grasses - 3-4 years, fruit crops- 20-30 years. Then they disintegrate or die.

The second difference is in the source of energy used. For natural biogeocenosis, the only source of energy is the Sun. At the same time, agrocenoses, in addition to solar energy, receive additional energy that a person spent on the production of fertilizers, chemicals against weeds, pests and diseases, for irrigation or drainage of lands, etc. Without such an additional expenditure of energy, the long-term existence of agrocenoses is practically impossible.

The third difference is that the species diversity of living organisms is sharply reduced in agroecosystems. One or several species (varieties) of plants are usually cultivated in the fields, which leads to a significant depletion of the species composition of animals, fungi, and bacteria. In addition, the biological uniformity of cultivated plant varieties occupying large areas (sometimes tens of thousands of hectares) is often the main reason for their mass destruction by specialized insects (for example, the Colorado potato beetle) or damage by pathogens (powdery hummock, rust, smut fungi, late blight and etc.).

The fourth difference is the different balance of nutrients. In natural biogeocenosis, the primary production of plants (crop) is consumed in numerous food chains (networks) and is again returned to the biological cycle system in the form of carbon dioxide, water and mineral nutrition elements.

In the agrocenosis, such a cycle of elements is sharply disturbed, since a person removes a significant part of them with the harvest. Therefore, in order to compensate for their losses and, consequently, to increase the yield of cultivated plants, it is necessary to constantly apply fertilizers to the soil.

Thus, in comparison with natural biogeocenoses, agrocenoses have a limited species composition of plants and animals, are not capable of self-renewal and self-regulation, are subject to the threat of death as a result of mass reproduction of pests or pathogens, and require tireless human activity to maintain them.

Under the numbers 3, 4, 5 - characterizes agrocenosis; 1, 2, 6 - natural biogeocenosis.

Answer: 345.

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 adaptation of living beings to the entire spectrum 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 between living and non-living things»;. 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: connections with such academic disciplines as 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, nitric and phosphoric acid, 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 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 in terms of gas and food regimes 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 detritus-eating 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 spacecraft use an open-type system with different degrees of regeneration.

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 all of them are 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 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:

• Agro-ecosystems, that is, those that are associated with human activities.
• 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 production organic matter before their decomposition into inorganic components.
• The interaction of species in ecosystems ensures stability and self-regulation.

Whole the world 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 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 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 is necessarily present in any ecosystem, but it can differ 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 cannot compete 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 ecologists of the world are already shouting with one voice that the world has come. Most scientists are sure that natural disasters, which have recently begun to occur more often, are nature's response 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.

No. 3. Among several indoor plants find monocot and dicot, name their distinguishing features.

The main feature of indoor plants is the venation of leaves.

Ticket number 12

No. 1. Pre-nuclear and nuclear organisms, their characteristics ika.

Biological diversity, its role in maintaining the sustainability of the biosphere.

No. 2. biological variety - variety species inhabiting the Earth, the diversity of natural ecosystems on the globe. 2. The diversity of species in nature is the reason for the variety of food, territorial relationships between them, the most full use natural resources, closed circulation of substances in natural ecosystem. The rainforest is a stable ecosystem due to the wide variety of species in it, the adaptability of organisms to cohabitation, and the optimal use of natural resources. An ecosystem consisting of a small number of species, such as a small reservoir, a meadow, is an example of unstable natural communities. 3. Reduction of species diversity as a result of human activity: the construction of cities, railways and highways, the cutting down of large tracts of forest, the construction of industrial enterprises, the plowing of land for agricultural land. Extinction is currently about 10% of higher plant species on Earth. Deforestation of tropical forests, in which a significant part of plant and animal species are concentrated, is a problem requiring application special measures forest protection. Over 60 species of mammals and over 100 species of birds have disappeared over the past 400 years. 4. Impact of pollution environment on species diversity, the reasons for its reduction. Thus, water pollution in rivers by industrial waste is the reason for the reduction in the number of crayfish, freshwater pearl mussel (mollusk), and some species of fish. The treatment of fields and gardens with pesticides is the cause of the death of birds that feed on insects infected with poisons. The ecosystem-dark nature of the reduction in species diversity: each extinct plant species takes with it five species of invertebrates, the existence of which is inextricably linked with this plant. 5. The role of biodiversity in maintaining the sustainability of the biosphere. The dependence of human existence on the state of the biosphere, on its biological diversity. Conservation of species diversity, habitats of plants and animals. Protected areas: nature reserves, biosphere reserves, National parks, monuments of nature, their role in preserving the diversity of life on Earth.

No. 3. Among tubes with seeds, choose the one that contains the seeds sown to a depth of 1-2 cm. Explain your choice.

If you sow the seeds to a depth of 1-2 cm, then you need to choose a test tube with small seeds, as they contain a small supply of nutrients. If such seeds are sown deep, then the plants developed from them will not be able to break through to the light due to a lack of nutrients. Small and rapidly germinating seeds (lettuce, radish, cabbage, etc.) are sown to a depth of 1-2 cm, and small, but slowly germinating seeds (onions, parsley, carrots, etc.) - to a depth of 2.0-3.0 see large (beans, peas) - to a depth of 6-7 cm.

Ticket number 13

No. 1. biological nature and social entity human.

1. Biosocial essence of a person. The subordination of human life to both biological and social laws. The formation of a person, as well as other organisms, in the process of evolution, the subordination of his life processes (nutrition, etc.) to biological laws. Significant differences between humans and animals are upright posture and labor, associated changes in the structure and life activity - the presence in the skeleton of a spine with four bends, an arched foot, structural features of the pelvis, hand, skull; an increase in the brain, the ability to work, create tools, communicate with each other, speak articulately, think abstractly, create science and art, accumulate and use the experience of previous generations, and pass it on to descendants. The impossibility of explaining these features only by the laws of biological evolution. The existence of the laws of development of human society, in accordance with which truly human traits are formed in the process of a person's life in society, his upbringing. Children raised from an early age among animals do not speak well developed speech can't think abstractly. 2. The role of man in the biosphere. Purposeful human impact on both inanimate nature and its inhabitants. Creation of new varieties of plants and animal breeds, changing the habitats of wild plants and wild animals, hunting for animals, collecting medicinal herbs, the use of meadows and steppes as pastures. Negative impact on the nature of industrial development, Agriculture, transport, land use for roads, housing construction on fertile soils, soil erosion, pollution of soil, air, water bodies, reduction in the number of species, the death of many of them. Reduction of biological diversity, increase in the number of species of insects, bacteria, fungi and other organisms as a result of human activities. Deterioration of environmental conditions necessary for the life of not only humans, but also plants, animals, fungi. The need to preserve the biological gene pool of man himself, to take into account the laws of nature in his economic activity, to develop measures to regulate the number of species, to preserve the habitat of organisms.

No. 2. Evolution of the organic world, its causes and results.

1. Causes of evolution. The existence of a huge variety of species on Earth (about 0.5 million plant species and about 2 million animal species). Formation of the diversity of the organic world in the process of its historical development- evolution. The influence of natural factors on the evolution of the organic world was first studied by the English scientist C. Darwin. His theory of evolution, proving that all organisms have the properties of variability and heredity. Variability is a property due to which organisms develop a variety of new features. Heredity - the transmission of traits by inheritance, their appearance in offspring. Death under the influence of various factors of animate and inanimate nature of a significant part of individuals, surviving to adulthood and leaving offspring only a small part of the most adapted individuals. Natural selection is the process of survival of individuals that are most adapted to specific environmental conditions. The emergence gradually, through many generations, from one species of new species, more adapted to life in changed conditions. 2. Results of evolution. The formation of new species, an increase in their diversity, as well as the formation of their traits of adaptability to the environment.

No. 3. Using tables and figures, describe the mole's adaptations to life in the soil. Explain how these adaptations could have arisen.

Living organisms living in the soil have various adaptations to the soil environment. In a mole, for example, the front legs are short and do not turn down, like in land animals, but to the sides: wide brushes are turned back. Fingers with strong sharp claws are connected by a leathery membrane. With such legs, the mole easily loosens the soil and makes holes in it. The eyes of the mole are underdeveloped and hidden by hair. With them, he distinguishes only light from darkness. Moles constantly live in the soil. They can leave the layers in which unfavorable living conditions are created, to other layers of the soil. In drought and winter, they move to deeper layers.

High soil density (compared to water and ground-air environments). In this regard, the habitation of highly specialized species in it, for example, an ordinary mole, in which, in the process of evolution, a body was formed that has the shape of a cylinder, pointed in front, covered with short thick hair, reduction of the auricles and organs of vision occurred. Development in connection with the burrowing lifestyle of short but strong forelimbs, intensive metabolism. The formation of adaptations for movement in the soil (for example, well-developed muscles, bristles - elastic formations on the ventral side of each segment in an earthworm - and other features of their structure) is the main direction in the evolution of soil inhabitants. The role of heredity, variability and natural selection in the formation of signs of adaptability to the environment.

Ticket number 14

No. 1. food, it importance in the life of the organism. Features of plant nutrition

1. Methods of nutrition. Nutrition is the process of absorption of substances from the environment, their transformation in the body and the creation of substances that are digestible by the body, specific to each particular organism. 2. Autotrophic and heterotrophic modes of nutrition. Creation of organic substances from inorganic in the autotrophic mode of nutrition. The use of ready-made organic substances in the heterotrophic mode of nutrition. The autotrophic method is characteristic of green plants and some types of bacteria, while the heterotrophic method is characteristic of all other organisms.