Competitive relations. types of competitive relationships

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Predation is direct food relationships between organisms in which some organisms are destroyed by other organisms. Examples: fox eating hares, tit eating caterpillars.

Competition is a type of relationship that arises between species with similar ecological needs because of food, territory, etc. Example: competition between moose and bison living in the same forest because of food. The negative impact of competition on both competing species (for example, a decrease in the number of moose and bison due to lack of food).

Symbiosis is a type of interspecies relationship in which both organisms receive mutual benefits. Examples of symbiosis: hermit crab and sea anemone, nodule plants and bacteria, cap mushrooms and trees, lichens (symbiosis of fungus and algae).

Among the huge variety of relationships among living beings, certain types of relationships are distinguished that have much in common among organisms of different systematic groups.

Symbiosis

Symbiosis1 - cohabitation (from the Greek sim - together, bios - life) is a form of relationship from which both partners, or at least one, benefit.

Symbiosis is divided into mutualism, protocooperation and commensalism.

Mutualism2 is a form of symbiosis in which the presence of each of the two species becomes obligatory for both, each of the cohabitants receives relatively equal benefits, and the partners (or one of them) cannot exist without each other.

A typical example of mutualism is the relationship between termites and flagellated protozoa that live in their intestines. Termites eat wood, but they do not have enzymes to digest cellulose. Flagellates produce such enzymes and convert fiber into sugars. Without protozoa - symbionts - termites die of starvation. In addition to a favorable microclimate, the flagellates themselves receive food and conditions for reproduction in the intestines.

Protocooperation3 is a form of symbiosis in which coexistence is beneficial for both species, but not necessarily for them. In these cases, there is no connection between this particular pair of partners.

Commensalism is a form of symbiosis in which one of the cohabiting species receives some benefit without bringing any harm or benefit to the other species.

Commensalism, in turn, is subdivided into tenantry, co-feeding, and freeloading.

"Living"4 is a form of commensalism in which one species uses another (its body or its home) as a shelter or home. Of particular importance is the use of reliable shelters for the preservation of eggs or juveniles.

The freshwater bitterling lays its eggs in the mantle cavity of bivalve mollusks - toothless. The laid eggs develop in ideal conditions supply of clean water.

"Community eating"5 is a form of commensalism in which several species consume different substances or parts of the same resource.

"Freeloading"6 is a form of commensalism in which one species consumes the leftover food of another.

An example of the transition of freeloading into closer relationships between species is the relationship between the sticky fish, which lives in tropical and subtropical seas, with sharks and cetaceans. The front dorsal fin of the sticker has been transformed into a suction cup, with the help of which it is firmly held on the surface of the body of a large fish. The biological meaning of the attachment of sticks is to facilitate their movement and settlement.

Neutralism

Neutrality7 is a type of biotic relationship in which organisms living together in the same territory do not affect each other. When an individual is neutral different types are not directly related to each other.

For example, squirrels and moose in the same forest do not contact each other.

Antibiosis

Antibiosis is a type of biotic relationship when both interacting populations (or one of them) experience the negative influence of each other.

Amensalism8 is a form of antibiosis in which one of the cohabiting species oppresses another, receiving neither harm nor benefit from it.

Example: light-loving herbs growing under a spruce suffer from severe darkening, while they themselves do not affect the tree in any way.

Predation9 is a type of antibiosis in which members of one species feed on members of another species. Predation is widespread in nature among both animals and plants. Examples: carnivorous plants; lion eating antelope, etc.

Co-competition is a type of biotic relationship in which organisms or species compete with each other to consume the same, usually limited, resources. Competition is divided into intraspecific and interspecific.

Intraspecific co-competition10 is competition for the same resources that occurs between individuals of the same species. This important factor self-regulation of the population. Examples: Birds of the same species compete for nesting sites. During the breeding season, males of many mammal species (for example, deer) compete with each other for the opportunity to start a family.

Interspecific competition11 is competition for the same resources that occurs between individuals of different species. Examples of interspecific competition are numerous. Both wolves and foxes hunt hares. Therefore, competition for food arises between these predators. This does not mean that they directly come into conflict with each other, but the success of one means the failure of the other.

For example, lampreys attack cod, salmon, smelt, sturgeon and others large fish and even whales. Having attached itself to the victim, the lamprey feeds on the juices of its body for several days, even weeks. Many fish die from the numerous wounds it inflicts.

All of the listed forms of biological connections between species serve as regulators of the number of animals and plants in the community, determining its stability.

Various forms of interaction between individuals and populations:

Lesson 14, 15

Practical work № 1, 2 Description anthropogenic changes in the natural landscapes of your area

Relationships between various organisms, in which they begin to compete with each other - this is competition. The subject area does not matter. In biological relationships, this is a type of biotic relationship. Organisms compete to consume limited resources. There are other types of competition, such as economic competition.

Rivalry in nature

Intraspecific competition is the competition between individuals of the same species for the same resources. Thus, self-regulation of the population is influenced by intraspecific competition. Examples of such competition: the nesting site of birds of the same species, competition between male deer and other mammals for the right to a female during the breeding season.

Interspecific competition is also characterized by competition for resources. But it happens between different species of individuals. Such competition (examples: fox and wolf hunting a hare) is very numerous. Predators compete for food. They rarely come into direct confrontation. As a rule, the failure of one turns into success for the other.

Intensity of competition

Organisms at the trophic level also have their own competition. Examples: competition for the consumption of a limited resource between plants, phytophages, predators, etc. This is especially noticeable at critical moments, when plants struggle for water during drought, when predators have a bad year and they fight for prey.

IN different conditions the intensity of competition between and within populations may vary. But there are no fundamental differences between types of rivalry. It happens that intraspecific competition is more intense than interspecific competition. It happens the other way around. If conditions are unfavorable for one species, they may be suitable for another. In this case, one species is replaced by another.

But in communities where there are many species, competition most often takes place of a diffuse nature (examples: many species simultaneously compete for a certain factor environment or for several factors at once). Duels occur only among mass plant species sharing the same resources. For example: linden and oak, pine and spruce and other types of trees.

Other examples of competition

Is it competition between plants for light, for soil resources, for pollinators? Absolutely yes. On soils rich in minerals and moisture, they form plant communities. They are thick and closed. Therefore, light for them is limited. They have to compete for it. Pollinating insects also choose a more attractive plant.

The animal world also has its own examples of competition. Is the struggle of herbivores for phytomass competition? Of course yes. Surprisingly, large-ungulates can compete with insects such as locusts and mouse-like rodents, which are capable of destroying most of the grass when they reproduce en masse. Predators compete for prey, and competition for food develops into a struggle for space. This is because food availability depends not only on ecology, but also on area.

Competition between species

As in the case of relationships between individuals of the same population, interspecific competition(examples were given above) can be asymmetrical and symmetrical. At the same time, asymmetric competition occurs more often. This is due to the fact that identical environmental conditions favorable for rival species are extremely rare.

Fluctuating resources usually occur in nature. Therefore, different competing species take turns gaining advantages. This leads to the development of coexistence of species and their improvement. They alternately find themselves in more or less favorable conditions. In addition, the size of the population influences the outcome of competition. The higher it is, the higher the chances of winning.

Tough fight

If you study everything thoroughly scientific works that describe competition, it may be perceived that in systems without or where immigration and emigration are reduced, very fierce fight. Such examples of competition between organisms include laboratory cultures, communities on islands or other natural situations with difficult to overcome obstacles to exiting or entering the system. If we are talking about ordinary open natural systems, then the probability of coexistence is much higher.

How does intraspecific competition manifest itself? Examples of such rivalry

An example of competition within one species of individuals is a population of grasshoppers of the same species. In search of food, they waste energy, exposing themselves to the danger of becoming food for other individuals. When their population density increases, energy costs for life support also increase with it. Then intraspecific competition increases. Energy costs increase, the rate of food consumption decreases, and the chances of survival are reduced to a minimum.

In plants the situation is similar. If there is only one seedling, it has a better chance of surviving to reproductive maturity than one that grows in dense growth. This does not mean that it will die, but, most likely, it will be small and undeveloped. This will affect the offspring. Therefore, we can conclude that an increase in population density reduces the contribution of an individual to the offspring.

Common features

To summarize, we can say that intraspecific competition has the following common features:

• The rate of resource consumption by individual individuals decreases.
• There are limited resources, due to which there is competition.
• Rival individuals of the same species are not of equal value.
• There is a direct dependence affecting an individual on the number of competitive brothers.
• The result of competition is a decrease in the contribution to the offspring.

Aggressiveness

Competitive struggle within one species can be expressed aggressively (actively). It can be psychological, physical, chemical in nature. It happens that students are asked the question: “What is aggressive intraspecific competition? Give examples of active competition.” Then we can talk about males competing for a female. They behave actively, demonstrate the superiority of their appearance, and try to outshine their opponent. It happens that with the help of smell they keep a competitor at a distance. It happens that they enter into battle with the enemy.

Competition in the economy

In economics, competition is viewed as part of the market mechanism. It balances supply and demand. This is a classic look. There are two more approaches to the concept of competition:

• it is competitiveness in the market;
• a criterion that determines the type of industry market.

There are different degrees of perfection of competition in the market. Depending on this, different types of markets are distinguished. Each type has its own specific behavior of economic entities. With this approach, competition is understood not as rivalry, but as a degree of dependence general conditions in the market on the behavior of its participants, existing separately from each other, but one way or another having certain dependencies.

Competition can be behavioral, structural and functional. In behavioral competition, there is a struggle between competitors for cash buyer by satisfying his needs. When structural competition occurs, analysis occurs market structure in order to determine the degree of freedom of buyers and sellers in the market, as well as ways to exit it. With functional competition, there is competition between old and innovative approaches, methods and technologies.

Research methods

In modern economic science, two methods of studying competition are used: institutional and neoliberal. Institutional theory takes into account economic, social, political, organizational, socio-psychological factors and features of a particular system.

Competition is a kind of incentive, a stimulus for development. Achieve high results in economic sphere only possible if there is competition. One can cite quite a lot of facts confirming this theory from world history.

Perfect Market

In conditions modern market distinguish between perfect and imperfect competition. Freedom of choice - that's it key concept, which assumes perfect competition. You rarely see examples of such a market. In 1980, product prices fell sharply in the United States Agriculture. At first, farmers blamed government agencies. But when they began to get to the huge commodity exchange in Chicago, they became convinced that the supply was huge and no one could artificially lower prices. Fair competition worked. The market united a very large number of participants from both sides. Prices were dictated by the market. Only the balance of buyers and sellers influenced the final cost of the goods. Farmers stopped blaming the state and took measures to overcome the crisis.

Perfect competition is the absence of limitations in sellers and buyers. This is the impossibility of controlling prices. With such competition, an entrepreneur can easily enter the industry. Buyers and sellers have equal opportunities to access market information.

An example of perfect competition can be seen by studying the first stages of development of industrial society. At that time, the market was dominated by products of standard type and quality. The buyer could easily evaluate everything. Later, these properties became characteristic only of the raw materials and agricultural markets.

• prices for goods are the same for all buyers and sellers;
• access to information about the market is free for all its participants;
• the product is identical, and the number of market participants on both sides is huge;
• any manufacturer can freely enter any sphere of production;
• no seller can influence pricing individually.

Imperfect market

Imperfect competition is a market where at least one sign of perfect competition is not observed. This type of competition presupposes the presence of two or more sellers who have the ability to influence pricing in one way or another. They are the main competitors. In an imperfect market, either sellers or buyers take into account their ability to influence price.

The following types of imperfect competition are distinguished:

• monopolistic competition (there are numerous examples, such as the mobile communications market);
• oligopoly;
• monopoly.

Monopolistic competition is the leading form in modern business. With it, quite a lot of entities offer one special product, informational, service or other nature. They are both monopolists and competitors, while possessing real levers of price control for their special products.

Oligopoly refers to an industrial market. Such an example of economic competition where oligopoly occurs can be found in the field of oil and gas production and refining. This competition is characterized by the presence of several largest companies who control significant part production and sales of products. At the same time, these companies seriously compete with each other. Each of them has its own market policy, which nevertheless depends on competitors. They are forced to reckon with each other. In such a market, a product can be either differentiated or standard. There are significant barriers to entry in this industry.

Monopoly is also a type of industry market. The monopolist is the only one of its kind. It cannot be replaced, not even approximately. He controls the price and volume of production. As a rule, he receives excess profits. A monopoly can be created artificially: exclusive rights, patents, copyrights, ownership of the most important sources of raw materials. It is almost impossible to enter such an industry. The barriers are too high.

One of the leading processes shaping the species and spatial structure of a plant community is competition. In essence, this is a rivalry that arises between populations or individual plants when they interfere with each other: there is not enough light, moisture, nutrients etc. At the same time, the mutual influence of woody plants can be very different.

Competition

Competition occurs when interactions between two or more plants or populations with similar ecological needs adversely affect the growth, development, and survival of each. Basically, this happens when there is a lack of any vital resource necessary for everyone - light, moisture, nutritional components.

Competition may be symmetrical (competing plants mutually limit resource consumption approximately equally) or asymmetrical (different mutual restrictions on resource consumption, i.e. one type has a greater influence on the other).

The dominant and the oppressed

The result of competitive relationships is clearly visible in the appearance of woody plants. In any forest (mixed, single- or different-aged), differentiation of trees in growth and development is observed.

• The strongest, largest specimens and with a powerful developed crown - dominant. There are few of them, but they are distinguished by the most intensive consumption of shared resources.
• The bulk of the forest consists of less strong, but normally developed trees of average size and relatively equal needs - indeterminate.
• Along with this, there are also clearly weak specimens that are lagging behind in development - oppressed.

During long-term competitive relationships, oppressed organisms die, and indeterminate ones become either dominant or oppressed. In forestry this phenomenon is called self-destruction. Similar interactions can be observed in an old even-aged spruce forest. All types of differentiation are clearly visible here - from strong developed trees to weak, dying ones, which find themselves in conditions of strong shading and after some time die from lack of light.

Tree competition using the example of a spruce forest

Suppression of competitors can occur due to the release of toxic compounds by underground and above-ground parts, the mutual interception of mineral nutrients and soil moisture by the root system and sunlight leaf apparatus, due to mechanical interactions.

Brother on brother

Competition is noted as between plants of the same species (intraspecific struggle), and between individuals of different species (interspecific).

• Within the same species, plants are similar and have similar requirements for the environment. In this case, the result of intraspecific competition will depend on the physiological characteristics and individual heredity of each individual organism, as well as on inequality individual conditions development, in particular the conditions of the microenvironment that will surround a particular plant (micro-lows and micro-highs of relief, excess or lack of moisture, protection from frost and sun, etc.).
• For example, within the same species or breed, the hereditary properties of seeds can vary significantly. Thus, oak seedlings growing from larger mature acorns, with other equal conditions grow more energetically and quickly overtake weaker competitors. That is, even small initial differences between individuals of the same species will be decisive for their further development.

Ours and others

Competition is much more complex and varied in mixed forest phytocenoses, consisting of several species and species of trees, numerous shrubs, grasses, mosses, and lichens. In this case, the antagonism between plants is often so strong that it leads to the depression of a significant part of the species and their death.

Moreover, the outcome of interspecific competitive relationships is determined not only by environmental conditions, but also by the species characteristics of organisms and their ability to adapt. Even closely related species general similarity requirements for growing conditions are always somewhat different from each other. With more intensive development of one of them, everything is captured large quantity necessary resources and the less competitive neighbor is gradually displaced.

For example, for mixed even-aged larch-spruce crops, spruce dieback occurs during dry periods. Thanks to a deeper root system, larch could use moisture from deeper soil horizons, which were inaccessible to the spruce root system.

Often the result of competition between various types depends on their numerical ratio. Thus, with the predominance of birches in young pine-birch trees, the pine gradually dies, and the predominance of pines leads to a lag in the growth and development of young birches. In oak forests, with an increase in the proportion of ash admixture (more than 30%), a weakening of the growth of the main species is observed. Ash has a higher transpiration capacity, which leads to more intense soil drying and worsening conditions for joint development.

In forest phytocenoses, competition between entire structural units – different layers of forest vegetation – is clearly visible. The denser the tree canopy, the less developed the underlying subordinate layers and the more depressed the individual plants that form them.

Paradoxical, but what better conditions existence in a phytocenosis, the more intense the struggle for life and the more intense the competition. This pattern is confirmed by data from foresters. In a comfortable environment, arboreal trees grow faster, the processes of crown closure, separation and death of oppressed specimens begin earlier. As a result, there is a higher percentage of dead specimens per unit surface area and fewer mature trees remain, but each individual organism will be better developed and will occupy a larger area.

Unfavorable relationships between plants will affect their appearance and viability (size, leaf color, degree of foliage and decorativeness change sharply), which can lead to the destruction of the intended grouping.

What do they use to hit the enemy?

Competing plants are able to actively influence each other. Suppression of competitors can occur due to the release of toxic compounds by underground and above-ground parts, the mutual interception of mineral nutrients and soil moisture by the root system and sunlight by the leaf apparatus, due to mechanical interactions.

As the lighting plays important role in the life of plant organisms, competition for light– one of the most acute and pronounced. At varying degrees trees that provide stronger shading gradually begin to overtake and suppress competitors. Lack of light can lead to falling branches and leaves, slower growth and development, and ultimately the death of plants. Similar relationships are observed in nature between shade-tolerant and light-loving breeds. Thus, dark coniferous species (spruce, pine, cedar) with dense crowns eventually displace the fast-growing but light-loving birch.

Tree competition: displacement of light-loving trees

Mechanical interactions are characteristic of dense co-growth of trees and manifest themselves in the form of mechanical damage to buds and leaves, as well as in the form of wounds and dry holes formed due to mutual friction of trunks and branches. In species that have flexible branches (birch, aspen, alder), it is common whipping– when swayed by the wind, their branches cause strong blows to the crowns of their neighbors, as a result of which they become noticeably thinner. In this case, young conifers are especially affected; their needles and apical buds are knocked off, growth slows down, and double or triple tips are formed.

An example of a strong root competition can be observed in a swamp pine forest, where the situation is aggravated by the extreme poverty of the soil of the raised swamp in nutritional components. Under such conditions, a sparse tree stand is formed, in which the root systems of neighboring trees overlap many times, forming a dense network.

Tree competition: swamp pine roots

To live in peace and harmony

When creating artificial plantings, the principle of mitigating the severity of competition between plant organisms is used.

The problem of combining incompatible things can be solved by selecting appropriate conditions and careful care.

• When choosing plants for planting, the biological characteristics of growth, development and adaptability of their species, breeds and forms are taken into account.
• You should also pay attention to their height, depth of penetration and shape of the root system, optimal timing of vegetation, flowering and fruiting, and uneven use of habitat resources by plants.

Otherwise, unfavorable relationships between plants will affect their appearance and viability (size, leaf color, degree of foliage and decorativeness change sharply), which can lead to the destruction of the intended grouping.

• In mixed plantings, it is good to combine light-loving and shade-tolerant species, species with shallow and deep root systems, with different periods of intensification of the absorption of nutritional components, demanding and unpretentious species.
• To reduce mutual negative influence between tree species with pronounced competitive relationships, corresponding accompanying neutral species or shrubs can be planted as a kind of buffer.
• The use of sufficiently mature seedlings when planting can significantly reduce competition between them by initial stage development and avoid significant losses.
• An important role in the formation of tree plantations is played by the choice of optimal planting density and the nature of the placement of trees, taking into account not only their decorative qualities, but also individual species features transformations over time.
• It is useful to pay attention to the origin of planting material - seed or vegetative. In the first years of life, trees of vegetative origin (root shoots, coppice) grow faster; during this period they successfully compete with seedlings, which, if not cared for, can fall out of the composition. Subsequently, after reaching the upper tiers, seed trees become biologically more stable.

In general, the topic of plant compatibility with each other and the search for the most harmonious combinations is very extensive, since the nature of the relationships between plant organisms is very complex and can manifest itself in various forms and varies depending on the age of plant organisms, changes in climatic and soil conditions.

We can list only a few well-known specific examples unwanted proximity of different breeds and species.

Paradoxically, the better the living conditions in a phytocenosis, the more intense the competition.

Undesirable neighborhood

Do not create mixed plantings birch trees And some conifers. Birch, as a rule, grows faster than conifers and drowns them out. Birch waste products can have Negative influence on the intensity of enzymatic processes in pine and larch. In addition, birch has a powerful root system, consumes a lot of water and deprives all neighboring plants in this regard. Similar effects can also be had maples. It is better to plant shade-loving and unpretentious plants under them.

Ate They are capable of strongly acidifying the soil, so only lovers of acidic soils can get along with them. Among them are ferns, hydrangeas, callas, and begonias.

“Poison” the soil, i.e. cause so-called soil fatigue, decaying leaves chestnutA, nut. This is due to the fact that the leaves of these plants contain phenolic compounds, which begin to be released during the process of decomposition.

An aggressive plant is considered sea ​​​​buckthorn, clogging the space surrounding it with its growth.

Intensively growing poplar is able to quickly overtake and suppress light-loving birches, elms, ash trees, and maples mixed with it, which develop poorly and take on an ugly or curved shape.

Depending on growing conditions, adversely affects growth tree species caragana tree. On dry soils root system located in upper layers soil and when planted together with oak, pine, and ash, it displaces their roots into the lower, less fertile layers.

Under certain conditions oak can drown out ash, maple, white acacia, birch, elm.

Should not be planted among linden and maple trees rhododendrons, since these trees have a shallow root system that quickly intertwines the roots of rhododendrons and intercepts moisture. In addition, their spreading crowns retain precipitation.

Some plants ( beech, sucker, many conifers) have very high allelopathic activity (from the Greek. allelon– “mutually” and pathos- “suffering”), therefore they rarely form single-species plantings. They experience suppression of their own adolescence due to the accumulation toxic substances, as a result of which the species displaces itself.

Many herbs (some faster, others slower) as they grow, they choke out neighboring plants, both herbaceous and tree-like, especially creeping varieties of junipers. First of all, this applies to grasses with long rhizomes or forming numerous root suckers, since it is very difficult to combat their expansion.

Suppresses the growth of other plants barberry. This shrub, like white acacia, horse chestnut , fir, viburnum, rose, lilac, rose hip And mock orange, actively suppresses the growth of other plants and belongs to the group of monoplants.

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Competition is the competition between organisms of the same trophic level (between plants, between phytophages, between predators, etc.) for the consumption of a resource available in limited quantities.

special role competition for the consumption of resources during critical periods of their scarcity plays a role (for example, between plants for water during a drought or predators for prey in an unfavorable year).

Fundamental differences There is no interspecific and intraspecific (intrapopulation) competition. There are cases where intraspecific competition is more intense than interspecific competition, and vice versa. At the same time, the intensity of competition within and between populations can vary depending on the different conditions. If conditions are unfavorable for one of the species, then competition between individuals may increase. In this case, it should be displaced (or more often, displaced) by a species for which these conditions turned out to be more suitable.

However, in multispecies communities, “dueling” pairs most often do not form, and competition is diffuse in nature; many species simultaneously compete for one or several environmental factors. "Duelists" can only be mass species plants that share the same resource (for example, trees - linden and oak, pine and spruce, etc.).

Plants may compete for light, for soil resources, and for pollinators. On soils rich in mineral nutrition resources and moisture, dense, closed plant communities are formed, where light is the limiting factor for which plants compete.

When competing for pollinators, the species that is more attractive to the insect wins.

In animals, competition occurs for food resources, for example, herbivores compete for phytomass. In this case, competitors of large ungulates can be insects like locusts or mouse-like rodents, which are capable of destroying most of the grass stand during the years of mass reproduction. Predators compete for prey.

Since the amount of food depends not only on environmental conditions, but also on the area where the resource is reproduced, competition for food can develop into competition for space.

As in the relationships between individuals of the same population, competition between species (their populations) must be symmetrical or asymmetrical. Moreover, a situation where environmental conditions are equally favorable for competing species is quite rare, and therefore relations of asymmetric competition arise more often than symmetric ones.

When resources fluctuate, as is usual in nature (moisture or mineral nutrition elements for plants, primary biological production for different types of phytophages, density of prey populations for predators), different competing species alternately gain advantages. This also does not lead to the competitive exclusion of the weaker, but to the coexistence of species that alternately find themselves in a more advantageous and less advantageous situation. At the same time, species can experience deterioration of environmental conditions with a decrease in the level of metabolism or even a transition to a dormant state.

“Ecological pyramid of energy” - Physical Education Minute. Energy transfers to each subsequent food level from the previous one. In a simplified ecological pyramid, the ratio of individuals of different trophic levels of the ecosystem is 1: 3: 4: 5: 17. Pyramid of numbers and biomass. Flows of matter and energy in an ecosystem. In the ocean, the biomass of living organisms is represented. Length of the food chain. The ocean contains the biomass of living organisms. The higher the level, the lower the total biomass and number of organisms.

“Cycle of matter and energy” - The mass of the dolphin is 50 kg. How does the circulation of substances occur in biogeocenosis? Some areas of the ocean. Most of the energy contained in food is released. Growth per unit of time. Ecological pyramid of biomass. Food chains are divided into two types. Producers (first level) have a 50% increase in biomass. Energy flow and circulation of substances in ecosystems. The circulation of substances and the flow of energy. Number of individuals at each nutritional level.

“Types of relationships between organisms” - Continuous improvement. Phoric relations. Centipedes. The commensal lives inside the host. Cannibalism. Sinoikia. Forms of relationships between organisms. Commensalism in animals. Paroikia is a type of commensalism. Sinoikia - tenancy. Interpopulation relationships. Stuck. Nutcracker bird. Epioikia is called epiphytism. Predation is a type of antibiosis. Forms of biotic connections.

“Energy in Ecosystems” - Position. Enzyme in nature. Structure of chlorophyll. Chemosynthesis. Flow of energy through living organisms. Biological cycle. Photomorphogenesis. Components of the photosynthetic apparatus. Optical absorption spectrum of chlorophylls. Absorption of light quanta. Molecules. Education. The meaning of photosynthesis. Transformation of energy in an animal cell. Energy in ecosystems. Productivity is provided by plant photosynthesis.

“Ecological pyramid” - Purpose of the study: To prove that the number of individuals included in the food chain is consistently decreasing. Ecological pyramid. Research on the topic: “Ecological pyramid.”