family psychology 

Natural and artificial biocenoses. Biocenosis - examples. Natural and artificial biocenoses What biocenoses can a person create

K. Möbius and G.F. Morozov formulated reciprocity rule, Whereby species in the biocenosis are adapted to each other so much that their community is internally contradictory, but a single and mutually interconnected whole . In other words, in natural (natural) biocenoses there are no useful and harmful birds, useful and harmful insects; there everything (even predators like the wolf) serves each other and is mutually adapted.

At the same time, changes that occur in biocenoses for one reason or another (for example, due to changes in climatic conditions) affect their stability in different ways. So, if one species displaces another, then there will be no significant changes in the biocenosis, especially if this species is not among the mass ones. Therefore, when replacing one predator (marten) in the forest with another (sable), which is able to get food both on the ground and on trees, the forest biocenosis will retain all its main features.

In case of loss of rare and small species, the main biocenotic ties also do not change significantly until a certain time. Thus, the spruce forest near the city can be preserved for a relatively long time and even regenerated despite the constant anthropogenic pressure and the disappearance of many species of plants, birds, and insects as a result. However, the species composition of such forests is gradually becoming poorer, and sustainability is weakening. Such a weakened, depleted biocenosis can collapse imperceptibly, for example, due to the depletion of mineral nutrition by trees, as well as due to a sudden and massive attack of pests. The basis of the stability of biocenoses is their complex species composition.

In those cases when the main species - environment-forming species - fall out of the composition of the biocenosis, this leads to the destruction of the entire system and the change of communities. Sometimes such changes in nature are made by a person, cutting down forests, overfishing in reservoirs, etc.

In fairness, it must be pointed out that the sudden "landslide" destruction of previously stable communities is a property inherent in all complex systems in which internal ties gradually weakened. The identification of these patterns is extremely important both for creating artificial communities and maintaining natural biocenoses. So, if it is necessary to restore forests, steppes, laying forest parks, they try to create a complex species and spatial structure of communities, for which they select species of organisms that complement each other and get along together.

Dynamism- this is one of the main properties of biocenoses. Long-term observation of an abandoned field shows that it is successively conquered first by perennial grasses, then by shrubs and, finally, by woody vegetation.

Any biocenosis depends on its biotope and, conversely, every biotope is influenced by biocenosis. Since climatic, geological and biotic factors are subject to change, the development or dynamics of biocenoses is simply inevitable. Another thing is that in each case it proceeds at a different speed.

The influence that a biotope has on a biocenosis is called share. Manifesting itself in a very diverse way, for example, through the influence of climate, it can cause a variety of consequences: morphological, physiological and ecological adaptations, the preservation or extinction of species, as well as the regulation of their numbers.

The influence exerted, in turn, by the biocenosis on the biotope is called reaction. The latter can be expressed in the destruction, creation or change of the biotope. There are many examples of destructive reactions that plants are responsible for. Mosses, lichens settle on a variety of rocks. The roots of higher plants increase the crevices formed in these rocks and, in addition, have a chemical effect with acidic secretions. Many marine invertebrates (clams, sea urchins, sponges) "drill" rocks. Digging soil animals mix it to a considerable depth. In this case, earthworms and termites play the main role here.

On the contrary, the creative reaction in terrestrial conditions is expressed in the accumulation of animal (corpses) and plant (fallen leaves) residues, which, due to a series of chemical changes (bacterial putrefaction), gradually turn into humus. Finally, biocenoses transform the local climate, creating a microclimate.

A review of the various interactions between biocenoses and biotopes shows that the main reasons that cause the development of biocenoses are climatic, geological, edaphic (soil) and biotic factors.

The level of impact of climatic factors can be assessed by the example of the changes that occurred in Europe during the ice and interglacial periods. Then, in the Quaternary period, with the maximum advance of the glacier, Central Europe was a tundra with dwarf willows, dryads and saxifrages, and the entire flora of the temperate climate was forced out to the extreme south. The fauna of the time included mammoths, hairy rhinos, musk oxen, and small rodents. The warming that occurred during the interglacial periods contributed to the return of grapes to areas north of the Alps, and the "heat-loving fauna", incl. ancient elephant and hippo managed to settle in Europe.

With regard to geological phenomena (erosion, sedimentation, mountain building and volcanism), they can also greatly change the biotope, which, in turn, will cause significant shifts in biocenoses. The ongoing development of soils (edaphic factors), which is due to the combined action of climate and living organisms, entails in parallel the development of flora.

Biological factors are the most common and fastest acting factors. One can point, for example, to the role of bison, whose number previously amounted to tens of millions of heads, in the development of the biocenoses of the American prairies. Such an ecological factor as interspecific competition also plays a huge role in this process.

At present, the determining factor in the development of biocenoses is economic, as well as military human activity. Fires, deforestation, laying roads, pipelines, rocket launches, the introduction (conscious or accidental) of new species of animals (especially microorganisms) or plants are just a few examples of human intervention in nature. They can lead to the rapid evolution of biocenoses, and sometimes to the disappearance of some species of organisms.

Question 1. What signs can you offer to characterize biogeocenosis?
Characteristics of biogeocenosis:
1) species composition;
2) population density;
3) the intensity of the impact of abiotic and biotic factors.

Question 2. How does the interaction of abiotic environmental factors manifest itself in the life of organisms?
In relation to environmental factors, there are types of heat-loving and cold-resistant, moisture- and dry-loving, adapted to high and low salinity of water. The deviation of the intensity of one of the factors from the optimal value can narrow the limits of endurance to another.
Liebig's rule
A factor that is in excess or deficiency compared to the optimal value is called a limiting factor, since it makes it impossible for the species to flourish under given conditions.
For example, low humidity makes equatorial deserts sparsely populated, although other factors (illumination, temperature, presence of trace elements) are satisfactory.

Question 3. What is the negative impact of ionizing radiation on living organisms?
Ionizing radiation has the most destructive effect on more highly developed and complex organisms, and a person is particularly sensitive to the effects. Large doses received by the body in a short time (minutes, hours) are called acute doses, as opposed to chronic doses that the body could withstand throughout its life cycle. Any excess of the radiation level in the environment above the background or even a natural high background can increase the mutation rate. In higher plants, sensitivity to ionizing radiation is directly proportional to the size of the cell nucleus. Animals do not have such a simple dependence; for them, the sensitivity of certain organs and systems is of the greatest importance. Thus, mammals are sensitive even to low doses due to the slight damage to the bone marrow and intestinal epithelium by irradiation. Radioactive substances can accumulate in soil, water, air and in the bodies of living organisms themselves. Transmitted and accumulated during transmission through the food chain.

Question 4. What is the significance for the sustainability of the biocenosis of its species diversity?
The richer the species composition of the biocenosis, the more stable the community as a whole.

Question 5. What is the ecological pyramid and what are the directions of selection at each stage?
Ecological pyramid rule
The mass of each subsequent link in the trophic chain progressively decreases.
This is because in each link of the food chain, with each transfer of energy, 80-90% of it is lost, dissipating in the form of heat. On average, 100 kg of the body of herbivorous animals is formed from 1 thousand kg of green plants. Predators can absorb only 10 kg of their body from this amount of food. Accordingly, the number of animals at each subsequent step of the pyramid is less. Graphically, this rule is reflected in the ecological pyramids. There are population pyramids that reflect the number of individuals at each stage of the food chain, biomass pyramids that reflect the amount of organic matter synthesized at each level, and energy pyramids that show the amount of energy in food at each stage.
Question 6. What are the reasons for the change of biocenoses?
In nature, less stable biogeocenoses are replaced by more stable ones over time. Their change is determined by three factors:
1) an orderly process of community development - the establishment of static relationships between species in it;
2) changing climatic conditions;
3) a change in the environment under the influence of the vital activity of the organisms that make up the community.

All wildlife that surrounds us - animals, plants, fungi and other living organisms, is a whole biocenosis or part of, for example, a regional biocenosis or a biocenosis of a separate part. All biocenoses are different in terms of conditions, and may differ in species of organisms and plants.

In contact with

Biocenosis is community, the totality of living organisms in the nature of a certain territorial area. The concept also includes environmental conditions. If a separate territory is taken, then within its limits there should be approximately the same climate. Biocenosis can extend to the inhabitants of land, water and.

All organisms in the biocenosis are closely related to each other. There are food connections, or with the habitat and distribution. Some populations use others to build their own shelters.

There is also a vertical and horizontal structure of the biocenosis.

Attention! Biocenosis can be natural or artificial, that is, man-made.

In the 19th century, biology was actively developing, like other branches of science. Scientists continued to describe living organisms. In order to simplify the task of describing groups of organisms that inhabit any particular area, Karl August Möbius was the first to introduce the term "biocenosis". This happened in 1877.

Signs of biocenosis

There are the following signs of biocenosis:

  1. There is a close relationship between populations.
  2. The biotic relationship between all components is stable.
  3. Organisms adapt to each other and groups.
  4. There is a biological cycle in the area.
  5. Organisms interact with each other, so they are mutually necessary.

Components

The components of the biocenosis are all living organisms. They are divided into three large groups:

  • consumers - consumers of finished substances (for example, predators);
  • producers - can produce nutrients on their own (for example, green plants);
  • decomposers are those organisms that are the final link in the food chain, that is, they decompose dead organisms (for example, fungi and bacteria).

Components of biocenosis

Abiotic part of the biocenosis

abiotic environment- this is climate, weather, relief, landscape, etc., that is, it is an inanimate part. In different parts of the continents, conditions will be different. The more severe the conditions, the fewer species will live on the territory. In the equatorial belt, the most favorable climate is warm and humid, so endemic species are most often found in such areas (many of them can be found on mainland Australia).

Separate area of ​​the abiotic environment called a biotope.

Attention! The richness of species within the biocenosis depends on the conditions and nature of the abiotic environment.

Types of biocenosis

In biology, the types of biocenosis are classified according to the following criteria.

By spatial arrangement:

  • Vertical (tiered);
  • Horizontal (mosaic).

Origin:

  • Natural (natural);
  • Artificial (man-made).

By type of relationship species within the biocenosis:

  • Trophic (food chains);
  • Factory (arrangement of habitats of the organism with the help of dead organisms);
  • Topical (individuals of one species serve as a habitat or influence the life of other species);
  • Phoric (participation of some species in the distribution of the habitat of others).

Spatial structure of biocenosis

Natural biocenosis

Natural biocenosis is characterized by the fact that it is of natural origin. In the processes taking place in it, a person does not interfere. For example: the Volga river, forest, steppe, meadow, mountains. Unlike artificial ones, natural ones have a larger scale.

If a person interferes with the natural environment, then the balance between species is disturbed. Irreversible processes are taking place - the extinction and disappearance of some species of plants and animals, they are indicated in "". Those species that are on the verge of extinction are listed in the "red book".

Consider examples of natural biocenosis.

River

The river is natural biocenosis. It is inhabited by various animals, plants and bacteria. The views will vary depending on the location of the river. If the river is in the north, then the diversity of the living world will be scarce, and if closer to the equator, then the abundance and diversity of the species living there will be rich.

Inhabitants of river biocenoses: beluga, perch, crucian carp, pike, sterlet, herring, ide, bream, pike perch, ruff, smelt, burbot, crayfish, asp, carp, carp, catfish, roach, path, silver carp, sabrefish, various freshwater algae and many other living organisms.

Forest

The forest is an example of a natural look. The forest biocenosis is rich in trees, shrubs, grass, animals that live in the air, on the ground and in the soil. Here you can find mushrooms. Various bacteria also live in the forest.

Representatives of the forest biocenosis (fauna): wolf, fox, elk, wild boar, squirrel, hedgehog, hare, bear, elk, titmouse, woodpecker, chaffinch, cuckoo, oriole, black grouse, capercaillie, thrush, owl, ant, ladybug, pine silkworm, grasshopper, tick and many other animals.

Representatives of the forest biocenosis (plant world): birch, linden, maple, elder, corydalis, oak, pine, spruce, aspen, lily of the valley, kupyr, strawberry, blackberry, dandelion, snowdrop, violet, forget-me-not, lungwort, hazel and many other plants.

The forest biocenosis is represented by such mushrooms: boletus, boletus, white mushroom, grebe, fly agaric, oyster mushroom, puffball, chanterelle, butterdish, honey agaric, morel, russula, champignon, camelina, etc.

Natural and artificial biocenosis

Artificial biocenosis

An artificial biocenosis differs from a natural one in that it created by human hands to meet their needs or the whole society. In such systems, the person himself designs the required conditions. Examples of such systems are: a garden, a kitchen garden, a field, a forest plantation, an apiary, an aquarium, a canal, a pond, etc.

The emergence of artificial environments has led to the destruction of natural biocenoses, the development of agriculture and the agrarian sector of the economy.

Examples of artificial classification

For example, in a field, a greenhouse, a garden or a vegetable garden, a person breeds cultivated plants (vegetables, cereals, fruit-bearing plants, etc.). So that they don't die certain conditions are created: irrigation systems for watering, lighting. The soil is saturated with the missing elements with the help of fertilizers. Plants are treated with chemicals to keep them from being eaten by pests, etc.

Forest belts are planted near fields, on the slopes of ravines, near railways and highways. They are needed near the fields in order to reduce evaporation, keep snow in the spring, i.e. to control the water regime of the earth. Trees also protect seeds from wind dispersal and soil from erosion.

Trees are planted on the slopes of ravines in order to prevent and slow down their growth, as the roots will hold the soil.

Trees along the roads are necessary in order to prevent snow, dust, and sand from drifting along the transport routes.

Attention! A person creates artificial biocenoses in order to improve the life of society. But excessive intervention in nature is fraught with consequences.

The horizontal structure of the biocenosis

The horizontal structure of the biocenosis differs from the longline one in that the abundance of species living on its territory changes not vertically, but horizontally.

For example, we can consider the most global example. Diversity, abundance and richness of the living world varies by zone. In the zone of the Arctic deserts, in the Arctic climatic zone, the animal and plant world is scarce and poor. As you approach the rainforest zone, in the tropical climate zone, the number and diversity of species will increase. So we managed to trace the changes in the number of species within the biocenosis, and even the change in their structure (since they have to adapt to different climate conditions). This is a natural mosaic.

And artificial mosaicism arises under the influence of man on the environment. For example, deforestation, sowing meadows, draining swamps, etc. In a place where a person has not changed the conditions, the organisms will remain. And those places where conditions have changed will be inhabited by new populations. The components of the biocenosis will also begin to differ.

Biocenosis

The concept of biogeocenosis and ecosystem

Output

To summarize: the biocenosis has different classifications depending on the origin, relationships between organisms and location in space. They differ in territorial scope and species that live within them. Signs of biocenosis can be classified separately for each area.

Ecology__Questions and answers of level "C"

Why can the number of commercial fish be sharply reduced when predatory fish are destroyed in the reservoir?

1) the destruction of predators leads to a sharp increase in the number of herbivorous fish and increased competition between them;

2) a large number of herbivorous fish contributes to a decrease in the food supply, the spread of various diseases among them, this will lead to mass death of fish.

What changes in the ecosystem of the meadow can be caused by a decrease in the number of pollinating insects?

1) reduction in the number of insect pollinated plants, changes in the species composition of plants;

2) reduction in the number and change in the species composition of herbivorous animals; 3) reduction in the number of insectivorous animals.

Based on the rule of the ecological pyramid, determine how much grain is needed for the forest to grow one eagle owl weighing 3.5 kg if the food chain looks like:

grain of cereals - mouse vole - polecat - eagle owl.

1) according to the rule of the ecological pyramid, the biomass of each subsequent trophic level decreases

about 10 times;

2) therefore, to feed the eagle owl, 35 kg of ferret biomass is needed (if the mass of one ferret is about 0.5 kg, then this is -

70 ferrets, 350 kg of vole mouse biomass is needed to feed the ferrets (if the vole mouse weighs about

100 g, then this is 35,000 voles), which need 3,500 kg of grain to feed.

Why is acid rain dangerous?

First of all, heavy metal oxides that enter the soil with rain are toxic. Underground waters penetrate into reservoirs and poison them. In turn, this threatens the death of the population of reservoirs. Poisonous substances also affect the composition of the soil, the root systems of plants, and this leads to the inhibition of their vital activity and death.

How does the structure of the biocenosis of a mixed forest differ from the structure of the biocenosis of a birch grove?

1) The number of species;

2) the number of tiers;

3) species composition, diversity of species.

How is a natural ecosystem different from an agroecosystem?

1. Greater biodiversity and diversity of food links and chains.

2. Balanced circulation of substances.

3. The participation of solar energy in the cycle of matter and long periods of existence.

What is the difference between biogeocenosis and ecosystem?

The ecosystem has arbitrary boundaries (from a drop of water with microorganisms to the biosphere), while the boundaries of the biogeocenosis are determined by the nature of the vegetation cover. The concept of an ecosystem is used both to describe simple parts of a biogeocenosis (a rotting stump in a forest), and for artificial complexes (an aquarium). Biogeocenosis is a purely terrestrial formation with clear boundaries.

Ecosystem and biogeocenosis are close concepts, but not identical. Any biogeocenosis is an ecosystem. For example, a forest is an ecosystem, but when we specify the type of forest - spruce forest, blueberry - this is a biogeocenosis.

Why is there sometimes an explosion in the number of individuals in populations, and then its sharp drop?

This happens for a number of reasons. For example, with an excess of food and a small number of predators, the number in the population increases. And due to the increase in the number of individuals, the amount of food decreases, the number of predators increases + the mass of animals in search of food is looking for new habitats, while some individuals die. All of the above leads to a decrease in the number of individuals.

What is an obligatory link in the agrocenosis food chain?

Man is an obligatory link in the food chain of agrocenosis.

Ants live in the stems of some plants. What is the use of the plant from the ants, and the ants from the plant?

Based on the rule of the ecological pyramid, determine how much plankton is needed for one 300 kg dolphin to grow in the sea if the food chain looks like: plankton - non-predatory fish - predatory fish - dolphin.

Response elements:

1) according to the rule of the ecological pyramid, the biomass of each subsequent trophic level decreases by approximately 10 times;

2) therefore, to feed a dolphin, 3 tons of predatory fish are needed, for its nutrition it is necessary 30 tons of non-predatory fish, which needs 300 tons of plankton to feed.

In America, many birds make nests in thorny cactus thickets. What is the name of such an interaction between living organisms and what is its biological meaning?

Response elements:

1) such interaction is mutually beneficial and is called symbiosis;

2) thickets of thorny cacti protect bird nests from predators;

3) birds destroy insects, pests of cacti, and fertilize the soil with droppings.

Based on the rule of the ecological pyramid, determine how many cereals are needed for the development of one golden eagle weighing 7 kg if the food chain looks like: cereals - grasshoppers - frogs - snakes - golden eagle.

Response elements:

2) according to the rule of the ecological pyramid, the biomass of each subsequent trophic level decreases

about 10 times;

2) therefore, to feed a golden eagle, 70 kg of snakes are needed (if the mass of one snake is 200 g, then this is 350 snakes), to feed these snakes, 700 kg of frogs are needed (if the mass of a frog is 100 g, then this is 7000 frogs), to feed these frogs 7 tons of grasshoppers are needed, and 70 tons of cereal plants are needed to feed these grasshoppers.

Fishermen know that there are more fish in the rivers and streams developed by beavers than in reservoirs where there are no beavers. Explain this fact?

Response elements:

1) beavers build dams that prevent the drift of small aquatic animals that serve as food

2) stagnant and shallow water in ponds dammed with beavers warms up well, which contributes to the creation

conditions for spawning of river fish and favorable development of fry.

What are the mechanisms of action of the anthropogenic factor on biocenoses?

Response elements:

    impact on biocenoses as a result of urban development, agriculture, deforestation, etc., which leads to a change in the ranges of species and a violation of their population structure;

    environmental pollution, which can inhibit the vital activity of individual species and their communities, cause the death of organisms and stimulate the mutation process;

    extermination of certain species (for example, valuable from a commercial or hunting point of view).

In the spruce forest, herbaceous plants are much less than in the birch grove. Explain this phenomenon.

Response elements:

1) in a grove, much more light passes through the crowns of trees than in a spruce forest, light is a limiting factor for many plants;

2) only shade-tolerant herbaceous plants can exist in a spruce forest.

What are the properties of biogeocenosis?

Biogeocenosis is an open, self-regulating system that is stable, capable of exchanging substances and energy. Biocenosis - part of the biosphere. Biogeocenosis consists of abiotic and biotic components. It is characterized by biomass, density of populations, its components, diversity of species. The living components of biogeocenosis are producers (plants), consumers (animals), decomposers (bacteria and fungi).

The food chains of natural biogeocenoses include different functional groups: producers, consumers, decomposers. Explain the role played by the organisms of these groups in the circulation of substances and the conversion of energy.

Response elements:

1) Producers - organisms that produce organic substances from inorganic ones, are the first link in the food chain and the ecological pyramid. In organic substances resulting from the processes of photo- or chemosynthesis, energy is accumulated.

2) Consumers - organisms that consume ready-made organic substances created by producers, but do not bring the decomposition of organic substances to mineral components. They use the energy of organic substances for their life processes.

3) Decomposers - organisms that in the course of life convert organic residues into inorganic substances, which are included in the cycle of substances in nature. The decomposers use the energy released at the same time for their vital processes.

What is the basis of ecosystem stability?

Response elements:

1) the diversity of plant, animal and other organisms

2) branched food chains (networks), the presence of several trophic levels

3) balanced circulation of substances

What determines the sustainability of natural ecosystems?

Response elements:

1) species diversity

2) the number of links in the food chain

3) self-regulation and self-renewal

4) closed circulation of substances

What are called population waves?

Fluctuations in the number of individuals in a population

The perch population in the river is declining as a result of water pollution by sewage, a decrease in the number of herbivorous fish, and a decrease in the oxygen content in the water in winter. What groups of environmental factors are presented in this list?

1) Anthropogenic.

2) Biotic.

3) Abiotic.

Humans use chemicals to control pests. Indicate at least 3 changes in the life of an oak forest if all herbivorous insects in it are chemically destroyed. Explain why these changes will occur.

Response elements:

1) the number of insect pollinated plants will decrease sharply, since herbivorous insects are pollinators of plants;

2) the number of insectivorous organisms (consumers of the second order) will sharply decrease or disappear due to disruption of food chains;

3) part of the chemicals used to kill insects will enter the soil, which will lead to disruption of plant life, death of soil flora and fauna, all violations can lead to the death of oak forests.

In some forest biocenoses, mass shooting of diurnal birds of prey was carried out to protect chicken birds. Explain how this event affected the number of chickens.

Answer elements: 1) at first, the number of chickens increased, since their enemies (naturally regulating the number) were destroyed; 2) then the number of chickens decreased due to lack of food; 3) the number of sick and weakened individuals increased due to the spread of diseases and the absence of predators, as a result of which their numbers decreased.

What is the ecological significance of nodule bacteria for plants?

Nodule bacteria form a symbiosis with leguminous plants and are involved in the fixation of atmospheric nitrogen into mineral compounds available to plants.

What is the name of an ecological factor, the quantitative value of which is beyond the limits of the endurance of the species, and thus it limits the distribution of the species even if all other factors are favorable?

Limiting factor / limiting factor.

What are the links between organisms called when one species uses waste products, dead remains, or even living individuals of another species for its structures?

factory connections.

What are the differences between land-air and aquatic habitats?

Response elements:

1) density;

3) amplitude of temperature fluctuations;

4) illumination.

What are the mechanisms of inhibition of the growth of the number of populations with an increase in its density?

Response elements:

1) the frequency of contacts between individuals increases, which causes them a stressful state, which reduces the birth rate and increases mortality;

2) emigration intensifies to new habitats, marginal zones, where conditions are less favorable and mortality increases;

3) there are changes in the genetic composition of the population, for example, rapidly breeding individuals are replaced by slowly breeding ones.

What are the main differences between agrocenoses and natural ny biocenoses?

Response elements:

1) insignificant species diversity;

2) incomplete circulation of substances;

3) the source of energy is not only the Sun, but also human activity;

4) lack of self-regulation.

Explain how a part of a spruce forest burnt out as a result of a forest fire will self-repair.

Response elements:

1) herbaceous photophilous plants develop first;

2) then shoots of birch, aspen, pine appear, the seeds of which fell with the help of the wind, a small-leaved or pine forest is formed;

3) under the canopy of light-loving species, shade-tolerant spruces develop, which will subsequently completely crowd out other trees.

Explain the advantage of biological pest control methods over chemical ones.

Pollution of the environment is prevented, while fauna and flora are preserved.

What is the basis for the formation of diverse food chains in ecosystems?

Response elements:

1) the diversity of species, the presence among them of producers, consumers, decomposers;

2) nutrition of species with a variety of foods (broad food specialization).

Why is the relationship between pike and perch considered competitive in the ecosystem of the river?

Response elements:

1) are predators, eat similar food;

2) live in the same reservoir, need similar conditions for life, mutually oppress each other.

Why can the number of commercial herbivorous fish be sharply reduced when predatory fish are destroyed in the reservoir?

Response elements:

1) the destruction of predators leads to a sharp increase in the number of herbivorous fish and increased competition between them;

2) a large number of herbivorous fish contributes to a decrease in the food supply, the spread of various diseases among them, this will lead to mass death

Make a food chain and identify a second-order consumer using all the named representatives: hawk, apple flowers, great tit, apple beetle.

Response elements:

1) apple flowers - apple beetle beetle - great tit - hawk

2) consumer of the second order - great tit

Why is the concentration of oxygen in the lower atmosphere decreasing now?

Response elements:

1) reduction of the green cover of the Earth as a result of deforestation and death of the phytoplankton of the World Ocean due to its pollution;

2) oxygen consumption by vehicles and industry.

What are the features of the biosphere as the shell of the Earth?

Response elements:

1) biogeochemical processes take place in the biosphere, the geological activity of all organisms is manifested;

2) continuous biogenic circulation of substances, regulated by the activity of organisms;

3) the biosphere converts the energy of the Sun into the energy of organic substances.

IN AND. Vernadsky wrote: "On the earth's surface there is no chemical force more constantly acting, and therefore more powerful in its final consequences, than living organisms taken as a whole." Explain what changes have occurred in the lithosphere due to the vital activity of living organisms.

Response elements:

1) soil formation;

2) the formation of a number of minerals: hard and brown coal, peat, limestone, etc.;

3) destruction of rocks.

Why does wet smog appear in urban environments?

The causes of wet smog in cities are high concentrations of air pollutants, dust, smoke, and damp windless weather.

Why is it necessary to maintain biodiversity to preserve the biosphere?

Response elements:

1) biodiversity - the basis of a variety of food chains and networks in ecosystems of the biosphere;

2) the diversity of food chains and networks - the basis of a balanced circulation of substances, maintaining the integrity of the biosphere;

3) a balanced circulation of substances is the basis of stability, self-regulation and conservation of the biosphere.

What organisms make up plankton?

There are three accumulations of biomass in the World Ocean: mineral, benthos and plankton. Plankton is formed in the upper layers of water, warmed up and illuminated by the sun. Plankton is very diverse. These are unicellular, as well as primitive multicellular plants and animals, united by a common property: the density of their body is equal to the density of water. Due to this, planktonic organisms do not sink and do not float, they are suspended in water, as if they are floating in it (the literal translation of this term is “soaring”).

We formulate the answer: “Plankton inhabits the upper layer of water to a depth of 100 m and is represented by organisms suspended in water. There are phytoplankton (unicellular and filamentous algae) and zooplankton (protozoa, copepods).

Why food chains are not long and usually consist of 4-5 links?

During the transfer of matter and energy, a significant part of the energy is lost (see reference material). Therefore, each new link in the food chain gets less and less energy. The complete loss of energy terminates the food chain. The reason is the lack of energy, which is lost in every link in the food chain.

How are the concepts of biotope and biocenosis related?

Biocenosis - a set of populations of different species that coexist in nature. Biotope (habitat) - the territory occupied in nature by a biocenosis. Combining with the biotope, the biocenosis creates a single system of living and non-living components - the biogeocenosis. Any biocenosis is combined with its biotope into an integral system - biogeocenosis.

What is the significance of changing daylight hours for living organisms?

Changing the length of the day (photoperiod) for most plants and animals is the main factor in the regulation of seasonal cycles. The response of organisms to changes in the length of the day is called photoperiodism. Thus, a decrease in the length of the day determines the onset of winter dormancy in plants and cold-blooded animals, the desire for flight in birds, molting in mammals, etc. Spring, lengthening day stimulates sap flow in trees and shrubs, the development of shoots from buds, the manifestation of nesting instincts in birds etc. The photoperiod serves as an accurate astronomical precursor to seasonal changes in temperature and other conditions.

What is the cause of the greenhouse effect?

The greenhouse effect is a process of gradual warming on our planet as a result of an increase in the concentration of anthropogenic impurities in the atmosphere (carbon dioxide, methane, nitrogen oxide, ozone, freons), which, passing the sun's rays, prevent long-wave thermal radiation from the earth's surface. Part of this absorbed thermal radiation is reflected by the atmosphere, returns to the earth's surface and heats the ground layer of air, creating a greenhouse effect. The main source of carbon dioxide of anthropogenic origin is the combustion of coal, oil, gas and other fuels.

What are the consequences of applying too much mineral fertilizer to the soil?

to environmental pollution.

Humans use chemicals to control pests. Indicate at least 3 changes in the life of an oak forest if all herbivorous insects in it are chemically destroyed. Explain why they will happen.

Response elements:

1) the number of insect pollinated plants will decrease sharply, since herbivorous insects are pollinators of plants;

2) the number of insectivorous organisms (consumers of the second order) will sharply decrease or disappear due to disruption of food chains;

3) part of the chemicals used to kill insects will enter the soil, which will lead to disruption of plant life, death of soil flora and fauna, all violations can lead to the death of oak forests.

What are the biochemical functions of living matter?

Biochemical functions of living matter:

1. Energy function - the accumulation of solar energy by plants (or chemical - by some bacteria) and its transfer through food chains. Green plants form 99% of the planet's primary production (about 150-200 billion tons of dry organic matter per year).

2. Gas - release and absorption of oxygen, carbon dioxide, methane, hydrogen sulfide in the process of photosynthesis, respiration, life processes.

3. Concentration function - an increase and accumulation by concentrator organisms in their veins of certain chemical elements (nitrogen, phosphorus, silicon, calcium, magnesium). As a result of this activity, accumulations of limestone, peat, coal, etc. occurred.

4. The redox function consists in the oxidation of substances containing atoms with a variable degree of oxidation. For example, the oxidation of carbohydrates to carbon dioxide and its reduction to carbohydrates.

5. The destructive function consists in the mineralization of organic remains to mineral compounds that are involved in the biological cycle.

What is the merit of the scientific ideas of V. I. Vernadsky?

The meaning of the teachings of V.I. Vernadsky about the biosphere lies in the fact that he showed the role of living organisms in the geochemical evolution of the planet Earth. This idea made it possible to realize the role of the biosphere in the fate of each individual and humanity as a whole. Since the biosphere is a global ecological system, and man is a part of this system, human activity in the biosphere can be both beneficial and detrimental to its existence.

What is the participation of functional groups of organisms in the biospheric cycle of substances?

Response elements:

1) producers synthesize organic substances from inorganic substances (carbon dioxide, water, nitrogen, phosphorus and other minerals), release oxygen;

2) all functional groups of organisms use and convert organic substances, oxidize them during respiration, absorbing oxygen and releasing

carbon dioxide and water;

3) reducers decompose organic substances to inorganic compounds of nitrogen, phosphorus, etc., returning them to the environment.

What organisms in an ecosystem contribute to the decomposition management of organic waste?

Organic waste refers to dead organic matter. Destructors (decomposers) mineralize (decompose) dead organic matter.

Answer: Decomposers - bacteria, lower fungi, some worms.

Why is the relationship between moose and bison in ecosy Is the mixed forest system considered competition?

The key concept that determines the wording of the answer is “competition”.

Competition is an antagonistic relationship between organisms (in this case, between different species) that use the same resources (food, territory, light, etc.)

Moose and bison are herbivorous animals.

Answer: They eat the same plant foods.

What governs seasonal phenomena in the life of an organization nisms?

An important role in the regulation of the activity of living organisms and their development is played by duration of exposure to light- photoperiod. A change in the length of daylight hours is, as it were, a trigger mechanism that sequentially turns on physiological processes that lead to growth, flowering of plants in spring, fruiting in summer and shedding of leaves in autumn, as well as to molting and fat accumulation, migration and reproduction in birds and mammals, and dormancy in insects.

Answer: Change in the length of the day (photoperiodism).

Mass extermination of wolves in a number of regions during led to a decrease in the number of ungulates, for example measures of deer. How can this be explained?

Answer: Wolves play the role of orderlies, destroy sick and weak animals, acting as natural selection. The disappearance of wolves leads to the spread of diseases among ungulates and a decrease in their numbers.

Why in the terrestrial food chain from link to link, as a rule, biomass decreases?

To answer it is necessary to use the rule of the ecological pyramid and the definition of the concept of "biomass".

Answer: Energy contained in organic substances is spent on vital processes in each link of the food chain, part of it (80-90%) is dissipated in space in the form of heat.

What are the reasons for the change of biogeocenoses?

Answer:

    reasons for the change of biogeocenoses: climate change, human activities, natural phenomena, as well as changes in the habitat of the species living in them;

    displacement of old species by more competitive species;

    an increase in species diversity, food chains, the formation of a closed circulation of substances - the reasons for the emergence of a more stable biogeocenosis.

Explain how self-regulation is carried out in reservoir on the example of the ratio of the number pike and roach .

Self-regulation in ecosystems is based on food connections. In this example, the pike is a predator that consumes roach for food.

Answer:

1) with an increase in the number of roaches, the number of pikes increases;

2) an increase in the number of pikes leads to a decrease in the number of roach;

3) in this way, self-regulation of fish in the reservoir is carried out

What is the difference between the ground-air environment and water Noah?

In the answer, it is necessary to highlight the properties characteristic onlyto for ground-air environment.

Answer:

    differences in temperature fluctuations (wide amplitude of fluctuations in the ground-air environment);

    degree of illumination (more than in water);

    density (less dense than water).

Clover grows in the meadow, pollinated by bumblebees. What biotic factors can lead to a decline in the clover population?

Biotic factors - factors of living nature. Answer:

1) decrease in the number of bumblebees;

    increase in the number of herbivorous animals;

    reproduction of competing plants (cereals, etc.).

Why are moose considered primary consumers?

Answer:

    feed on plants, consuming their organic matter;

    use the energy contained in organic substances;

    serve as food for predatory animals.

What is the difference between artificial and natural biocenosis?

Natural biocenoses are natural communities, and artificial ones are created by man.

What determines the stability of the biocenosis?

The stability of the biocenosis depends on the diversity of species and layering.

Questions

1. Why are there consumers of the second order, but there are no producers of the second order?

Producers form organic matter by consuming the energy of the sun. This means that they are all the first recipients of this energy, they all belong to the first order. Consumers can obtain organic matter by eating both herbivores and predators.

2. Why are cases of mass reproduction of pests observed much less frequently in natural biocenoses than in artificial ones?

Natural biocenoses are characterized by a wide variety of species. Artificial biocenoses have one or more sharply predominant species. This factor contributes to the mass reproduction of pests that have enough food.

3. Why can an aquarium, together with its inhabitants, be considered an artificial biocenosis?

The composition of the flora and fauna, as well as the number of individuals, a person regulates at his own discretion.

4. Why is the destruction of pest beetles and their larvae (for example, Colorado potato beetles) by hand collection the safest for other organisms in nature?

When using the manual collection of pest beetles and their larvae, human actions are directed specifically to a certain species, without any effect on other organisms. During chemical treatment, the impact is directed to the entire area and to all organisms located on it. At the same time, not only pests are destroyed, but also their natural enemies. This can further lead to a sharp increase in the number of pests themselves.

5. Why do organisms-producers live in the upper layers of a reservoir, consumers can live at different depths, including the bottom, and decomposers are mainly bottom dwellers? Give examples of organisms belonging to each of these groups?

Producing organisms live in the upper layers of the reservoir, since their life is directly related to the amount of sunlight. The producers of water bodies include phytoplankton and algae. Consumers feed on other organisms, so they can live at any depth. The consumers of water bodies are fish, mollusks, insects and their larvae, amphibians. Decomposers concentrate at the bottom of water bodies, as they feed on the remains of plants and animals that settle to a depth. Decomposers are represented by bacteria, worms.

6. Why is there such a sequence of events: the development of crustaceans as part of zooplankton begins after the appearance of phytoplankton, while the spawning of some fish begins only after the accumulation of a sufficient amount of phytoplankton?

Phytoplankton is the main food source for zooplankton. Fish feed on zooplankton. When there is enough zooplankton, fish spawning begins.

7. Why is a specific composition of the animal population with a predominance of insect pests formed in agrocenoses? What other features of the life of these insect pests can you name?

A lot of plants of the same species live in the agrocenosis (monoculture), therefore, good conditions are created for consumers feeding on this species. The life of these insects directly depends on the type of plants that a person will plant. Each insect pest feeds on a specific group of plants. Herbivorous animals that have switched to eating cultivated crops find favorable conditions in agrobiocenoses and can severely damage cultivated plants. Sometimes in agrobiocenoses there are outbreaks of mass reproduction of pest animals, for example, a bug of a harmful turtle in wheat fields, a Colorado potato beetle in potato fields, a cabbage white butterfly in cabbage fields, field mice and voles when growing crops. Complexes of organisms, except for cultivated plants, in agrobiocenoses, as well as in natural biogeocenoses, are formed as a result of the struggle for existence and natural selection. However, man, by creating favorable growth conditions for plants of cultivated species, suppresses organisms of other species. For example, with a large number of weeds and insect pests, people use various chemical methods for their destruction.

Tasks

Prove that spatial and temporal layering increase the stability of biocenoses.

The stability of biocenoses depends on the richness of their species composition. The more spatial tiers can be distinguished in the biocenosis, the more life niches exist in it. This means that more species will inhabit such a biocenosis. Animals change their position during the day, year, life, spending a longer time in one or another layer than in others. Various invertebrate inhabitants are associated with certain depths of the soil, but they do not have a strict confinement to the underground layers. Thus, animals are characterized by temporal layering. Temporary layering allows you to maximize the use of biocenosis resources, which also increases its stability.

Give examples known to you that confirm the presence of temporal or spatial tiering in animals.

Examples of spatial layering: In mixed forests, birds and some insects live in the crowns of tall trees. The second tier is inhabited by nesting birds and squirrels below. The third tier is inhabited by forest mammals (roe deer, elks, wolves, foxes), litter of grasses and leaves is inhabited by worms, larvae, beetles.

Temporal layering: seasonal flights of birds, nesting time, egg laying.