What leads to human activity in the ecosystem. Brief description of the activities of a person who change the balance in natural ecosystems

Shows a clearly pronounced unity of the structure and operation. It is easy to describe with water, just like: rods, river, river, puddle, pond, lake, sea. And more complicated, - as an ecosystem.

The main components of the ecosystem

I came to a conclusion,

- writes a famous American scientist E. Odum -

what is the same as the frog consider the classic object of studying the animal organism, the pond is an example for the initial study of the ecosystem ... without overloading for a beginner researcher, a large number of parts in the pond can be collected, for studying four the main components of the ecosystem.

What is this four components, composite parts environmental system (and on the scale of the pond, and on the scale of the entire biosphere, which can be perceived as an ecosystem of the planet Earth)?

1. First of all, these are non-living substances - the main components of the medium, inorganic and organic terms of it.
2. Then manufacturers, mainly earth plants, which from an inanimate medium are removed under the influence of solar energy various substances and create, produce a lot of live matter.
3. Next, all other living beings are coming, which live, or consuming the mass of green plants, or devouring other animals.
4. Finally, the mushrooms and bacteria that exist due to dead tissues of animals and plants: they proceed and decompose these fabrics on simple substances that are used again by plants.

Frog - frequent inhabitant of the reservoir.

Ecosystem

Four components and one cycle, cycle of substances in nature. From simple substances through plants, animals, mushrooms and bacteria - again to simple substances. This mill turns continuously in the pond, and in the ecosystem of the planet as a whole. And the engine is solar energy. In this way, ecosystem Such a system from non-living and living components can be considered, in which these all four components act, live, develop. From here we can conclude that ecosystem is not a stone, it is lively, composite parts are combined, connected to one large whole. If any components work poorly, other parts of this whole take on the share of their work. Therefore - ecosystem is very stable, balanced, balanced, is in homeostasisAs environmentalists say. Homeostatic mechanism Allows the ecosystem not only to adjust the equilibrium state of the system, but also to restore the balance, if it is broken. Until then, of course, the anthropogenic press does not become so powerful that no homeostasis saves the stability of the ecosystem.

Pond as ecosystem

Considering pond as an ecosystem, You can make three most important environmental outputs:

1. all elements of this reservoir are closely linked to, interact, violation of one of the elements causes a violation of the structure and life of the entire pond;
2. the system is in some equilibrium, homeostasis and is able to restore this equilibrium if the intervention only disrupts this balance, and does not destroy the connections themselves, does not cause an ecological system catastrophe;
3. like a living organism, the system lives, it appears, develops, progresses, reaches a heyday, then experiences decline, regression and death (example: time reservoirs, which are formed by melting of snow, in the flood and usually dry up, die in summer).

Assessment of the state of the water branch

For assessing the state of the water branch should be considered:

1. Anthropogenic pressure on any of the components of the system. Suppose, in a closed reservoir there is intensive amateur fishing of fish, exceeding the permissible degree of operation. To maintain the fish herd, it is possible to periodically, you can make a young in the reservoir. Another example: the density of fish landing in the reservoir when buried it was so high that the feeds do not have enough feed. It is necessary to make feed from the outside, feed fish.
2. Anthropogenic pressure on the entire system as a whole is so strong that equilibrium is not restored. Example: washing in water bodies, motorcycles or other vehicle (On the damage left on the surface of the water of the film of petroleum products everyone is known). Or intensive use of the water boat owners.
3. "Age" and the stage of development of a water branch. In particular, it is necessary to see the condition of water and fish in it. It happens that on the accounting of water bodies before the deployment of the operation to save fry from them takes several days. So, when taking into account, you need to see if the fry will withstand these few days, maybe the water is so bad, the fish are choking, and the whole reservoir is close to death that the operation on the salvation of the juvenile is impossible to postpone.

Purity of the reservoir is an important factor for assessing the state of the water ecosystem.

Reservoir as an ecosystem - its biogeocenosis

The reservoir system can be called biogeocenosis - the union of living and non-living parts. We are also interested in the environment of ecology. If you move away in the direction of the inanimate component of the system, then three subsequent form biocenosis. In the biocenosis of the reservoir, too, homeostasis, equilibrium, linking all its components, is development. You can imagine biocenosis in the form of chess figures - separate types of animals and plants: everything goes differently and apart, but everyone is interconnected and in general form the game, life on a chessboard. Of all biocenosis bonds, it is more important to catch the food chain. This chain always begins with the consumption of solar energy, therefore, its beginning - plants. Let's try to make a food chain. Microscopic plankton algae. Consume Daphny's wraps, their small larvae of insects, who become food of fishes, and this young, in turn, eat bigger fish, the same appetites devour the pikes, pike, well, and these fish are already catching out of the reservoir. A good food chain turned out. By the way, all that we consume, besides the cooking salt and water, is solar energy, "missed" through the food chain. The shorter the chain, the more fully, without loss, this energy comes to us. Therefore, people or animal predators on land rarely feed on carnivorous birds and beasts is an irrational chain elongation. Only in the water we are happy to catch and then eat predators, such as perch, pike perch. But it happens that the food chain is obtained in the reservoir and not so prosperous. For example: Algae - Daphnia - Larvae - Flinks - Yershi. And pike? Pershi remains, but due to sharp spikes on the fins, they do not like their toothast predators. It's not to get to the fools, they are in shallow water, there are not very familiar there, but Yershi is sinking there. By itself - excellent fish in the ear, but in a reservoir with more valuable fish, he acts as a competitor and turns into a weed harmful fish. It is clear that this should be taken into account when evaluating a reservoir, and then together with specialists to help valuable fish: organize a kind of "weeding" of a water branch from weeds.

Relationship between adjacent species in the reservoir

In biocenosis there may be not tense and tense relationship between adjacent species in the reservoir. For example, tense foods - This is when the species compete due to similar feed. The ripping of water bodies by the type of fish that feeds the same foods as the old-timers fish in this reservoir will not give effect. Another thing is, if the food competition of fish species is possible to avoid food competition due to the discrepancy between their nutritional needs. Then the old-timers live successfully, and the newly universes of the fish grow well, give a good catch. IN lately Fish trees are trying to exhaust to carry out not one type of fish, but by several non-competing fish, for example, carp and peel. The brilliant result gives an intercourse in a pond of a thick carp, white Amur and carp. Carp collects food near the bottom, a thick-carob is powered by plankton, phytoplankton (blooming water), and White Cupid eats the highest aqueous vegetation.

Water appraisal assessment

For evaluating the water branch It should be attributed to natural or to reservoirs. The first are rivers, lakes. And pond? It, of course, an artificial reservoir formed by the dam, but not every pond can be considered a reservoir. Maybe its size is crucial? No, not dimensions, not the volume of water is important. The main sign of the reservoir - and a huge and small pond - is the ability to regulate water consumption from the reservoir and its level.
The reservoir is an artificial reservoir.

Fishwater ponds

For fish farming, such reservoirs are most convenient, from which water can very much. Usually this fishwater ponds. After the water is descended, it is possible to replenish the water again and grow up only by the rocks of the fish that give the greatest effect when growing. Running reservoirs - best tool Fighting fish competition, the best "weeding" of the reservoir from fish-weeds. Productivity of reservoirs It can be enhanced by other paths, for example, in the reservoir feed for fish or the introduction of feed organisms, which themselves will quickly multiply the joy of fish and fish. The productivity of water bodies contributes to the removal of enemies of fishing fish. The enemies of fish can be vertebrate - birds, animals, but may be invertebrates. Many insect larvae eat fry fry, and in general, all invertebrates in the reservoir destroy more food than all the fish taken together of this reservoir. And it is also necessary to take into account the assessment of the shores, shallow and bays, the nature and accumulation of water vegetation, the temperature of the water in different places and warming up at different depths ... Therefore, it is a very complex object of nature.

Biocenosis reservoir

In other words, the reservoir is a living organism, a complex of non-living and living components forming biocenosis, and biocenosis has youth, maturity, old age. If a biocenosis reservoir Today contributes to spawning, the development of valuable fish, then our task is to maintain this age of the reservoir, try to move away from its aging. If the biocenosis of the reservoir is inclined to aging, it is necessary to carefully establish the causes of this phenomenon and, if possible, try to remove a number of these reasons and rejuvenate with water.

Pipe examination

To determine what state is water, I must examine it.

• First of all, the look of the reservoir - river, river, lake, lake;
• reservoir size;
• water movement - flowing, semisoteral, standing.

• Along with speed taken into account smooth flow: With a large bias, the river water may rush with greater speed, but in the northern rivers it is usually a smooth rapid flow, and in the south in the mountainous areas the river speed is often higher, the water forms rashes, waterways among stones. In closed lakes, water mobility depends on the nature of the shores: with open shores, the wind freely walks, forming the waves and stirring the aqueous mass, in the forest lakes, the water mirror rarely frowns from the wind and the water is weakly mixed, the lower layers can be much colder, may be poor oxygen. It means that the characteristic of the reservoir includes a description of its shores. The dimensions (length, width) and the depth of the reservoir are determined.
• O. Information the greatest depth The characteristic of the reservoir should be combined with information about smaller bays, well heated shallow. Determine the transparency of water, color, taste.
• Water samples on acidity Delivered to the laboratory for analysis. For these samples, it is possible to determine the sources of water pollution and submit signals to the sanitary and epidemiological station.
• It is not always easy to prevent reservoir pollution. A large role in compliance with pure water is played sources Rivers and rivers feeding reservoirs. Sometimes these springs are contaminated, the shores are flooded, garbage falls into the water. It is necessary to clean the spring, install benches around them, build bridges from which water can be gained without destroying the shore. The bottom of the Rodnikov must be cleaned from the garbage, El, Korjig. All detected springs are numbered, are recorded in the characteristic of the main reservoir, if possible, their location is applied to the map, the topographic scheme. There are general requirements for the composition in water bodies. When estimating the oxygen content in water in the field, if the water is not strongly contaminated, you can proceed from averages.

Above 30 ° C, the water is heated only in shallow water, fish such warm water, poor oxygen, do not like and deploy to depth. The widespread warming of water above 25 ° C is practically found only in small, depressed water bodies and from such fish reservoirs it is necessary to relocate the most urgent. Finally, assessing the reservoir, its passport includes data on the inhabiting fish and other water inhabitants, including enemies of fish. Water Plant Information Entered into the passport and water Plant Information.
Aquatic plants are an important element of any reservoir. Algae and Mossi. - original aquatic plants. Algae I. moss Fournyalis fully immersed in water, moss Sfagnum It has water environmental races growing under water (usually in forest lakes), the most often sphagnum is growing through the swampy shorts temporarily filled. These thickets are useful for the fry, although long threads of green algae sometimes grow so that the fry in them are confused and dying. Nevertheless, in a healthy ripe reservoir, these plants are not expanded by a solid mass. Otherwise it is the case with higher water vegetation - flower plants. These plants earlier, during the evolution, left the water, moved to land, and then individual representatives of the land plants again went into water. But it is characteristic of them all one - almost all of them did not suffer from the final connection with the former homeland - air Wednesday. Duckweed floats on the surface of water, cube and pita put on the surface of the leaves and flowers (do not bloom if the leaves have not reached the surface), elday and Peristoliste raise the water flowers, kamysheys and Social They grow above the water, only the roots, the lower part of the stem in the water. If you look at these plants, we will see that in the reservoir they are usually species communities: here's sand with the forest from eldine, Near the bay with a rogolistnik, gidly threaten the talks, the green plates of water lily float deeply. Rogolitnik - The only of higher plants, losing the connection with the air: it even flowers in the water. He has no roots, he is heavy, immersed in water. If the rogolistnik's thickets are tightly filled out, the tops of the stems reach the surface of the water, it is necessary to cut forward these thumbs up: they are crazy in them, and the predatory insects develop there successfully, podkrauly the fry. Thickets of rogolidnik are easily removed by hand, rakes, they are squeezed ashore, away from water. It is bad when the Elday burly grows up, her thickets also interfere with the fishes, create an overlooking zone for them. To remove the eldeute as easily, her root-anchors are loosely held a plant on the ground. The surface occurs similar to a rogue, with small excised leaves floating plant from light green to bright purple in summer. Fluffy stems float horizontally, abundantly branched, flowers - above the water. If you look at these stems - bubbles are visible among the leaves. This is a predatory bubble plant. In bubbles can penetrate minor animals, but there is no back from the bubbles. The pounding or male fishes stuck, then the juices of the plant dissolve production, and the walls of the bubble suck the nutrient solution. It is clear that this predator should not be places in spawning reservoirs, on the shallow, where the natural spawning of fish occurs. Pemphigus not only can encroach into fry fish - in their most difficult and responsible stage of life, when they are weak and helpless immediately after Icraeva, it is also the food competitor of fry, absorbing the inconspicable amounts of nutritious tracts and raschkov - primary food of fish kids . Floating on the surface duckweed All kinds and the near-surface species - three-dollar rods (its leaves do not touch air) are not terrible until they begin to tighten all the creek, and then the whole reservoir. Uploading the entire surface of the rod - a sign of aging of the reservoir. Such rickety "ice" must be removed. From the reservoir, the roason is caught with a bag, clamped on a square frame, a dense sacc. Rock - good vitamin additives to the feed of pigs and birds, so it is useful to dry it, collect and use on farms. Finally, rhino, Sing, Reed - rigid coastal vegetation. If it is a bit along the shores, it does not interfere, and if these semi-water herbs grow up, they interfere with fish farming, can absorb the whole shallow reservoir, turn it into

An aqueous is called an ecosystem for which the natural habitat is water. It is she who determines the uniqueness of a particular ecosystem, species diversity and its stability.

The main factors that affect the aquatic ecosystem:

1. Water temperature
2. Its chemical composition
3. Number of salts in water
4. Water transparency
5. Oxygen concentration
6. Availability of nutrients.

The components of the aqueous ecosystem are divided into two types: abiotic (water, light, pressure, temperature, the composition of the soil of the day, the composition of water) and biotect. Biotics, in turn, is divided into the following subspecies:

Products are organisms producing organic substances with the help of sun, water and energy. In the aqueous ecosystems, the producers are algae, in shallow water bodies - coastal plants.

Ratescents - organic organisms. These are a variety of views of marine animals, birds, fish, amphibians.

Main types of water ecosystems

In ecology, water ecosystems are accepted for freshwater and marine. The basis of this division is the indicator of water salinity. If in the water liter contains more than 35% of salts - these are marine ecosystems.

The sea includes oceans, seas, salted lakes. To freshwater - rivers, lakes, swamps, ponds.

Another classification of aquatic ecosystems is based on such a sign as the conditions of creation. It allocate natural and artificial. Natural created with the participation of the forces of nature: the sea, lakes, rivers, swamps. Artificial water ecosystems create a person: artificial ponds, reservoirs, dams, canals, aquatic farms.

Natural aqueous ecosystems

Freshwater ecosystems

Freshwater ecosystems - These are rivers, lakes, swamps, ponds. All of them occupy only 0.8% of the surface of our planet. Although more than 40% of well-known fish science live in fresh reservoirs, freshwater ecosystems are still significantly inferior in the species diversity by sea.

The main criterion for the distinction of freshwater reservoirs is the flow rate of water. In this regard, standing and flowing. Student include swamps, lakes and ponds. To flow - rivers and streams.
For standing water ecosystems, a pronounced distribution of biotic organisms is characterized depending on the water layer:

In the upper layer (littoral), the main component is plankton and coastal levels of plants. This is the kingdom of insects, larvae, here inhabited turtles, amphibians, waterfowl, mammals. The upper layer of water bodies is hunting grounds for herds, caravals, flamingos, crocodiles, snakes.

The middle layer of the reservoir is called a profound. It gets much smaller than sunlight, and the food is served by substances deposited by their upper layer of water. Beautiful fish are inhabited here.

The lower layer of water is called Bental. A huge role Playing the composition of the soil, El. This is the habitat of the bottom fish, larvae, mollusks, crustaceans.

Sea ecosystems

The biggest sea ecosystem is the world ocean. It is divided into smaller: oceans, seas, salted lakes. All of them occupy over 70% of the surface of our planet and are an essential component of the Earth's hydrosphere.

In marine ecosystems, the main component producing oxygen and nutrientsis phytoplankton. It is formed in the upper layer of water and under the action of solar energy produces nutrients, which then settle in the deeper layers of the reservoir and serve me for the rest of the organisms.

Large marine ecosystems are oceans. In the open ocean, species diversity is small compared to coastal zones. The bulk of living organisms is concentrated at depths of up to 100 meters: it different kinds Fish, mollusks, corals, mammals. IN coastal zones Sea ecosystems species diversity is complemented by numerous types of marine animals, amphibians, birds.

In the coastal zones of marine ecosystems allocate smaller (on the territory): mangrove swamps, shelves, limans, lagoon, salt marshes, coral reefs.

Places on the coast where sea \u200b\u200bwater Mixed with fresh (mouthpid), are called estificaries. The species diversity here is achieved maximum.

All marine ecosystems are very stable, capable of resisting human intervention and are rapidly restored after anthropogenic influence.

Artificial aquatic ecosystems

All artificial aquatic ecosystems are created by a person to meet their own needs. These are a variety of ponds, canals, creek, reservoirs. Smaller include oceanariums, aquariums.

For artificial water ecosystems are characteristic of the following features:

• Small number of species of plants and animals
• Strong dependence on human activity
• The instability of the ecosystem, as its viability depends on the influence of man.

2. Features of abiotic elements ecosystems of lakes and reservoirs

Approximately the 70s of the 20th century, in limb studies, serious attention was paid to the principal differences between reservoirs and lakes. It is enough to note that the classic of modern Limnologies D. Khatchinson attributed reservoirs to one of the types of lakes [Hutchinson, 1963]. The increase in the number of reservoirs in the world in the middle of century, the relevance of the assessment of their environmental state due to the task of preservation high Quality Waters in the sources of economic water supply stimulated the in-depth limited studies of these water bodies. As a result of these studies, significant differences in the functioning of the reservoir ecosystems compared with the ecosystems of the lakes. The cause of these differences protrude mainly the abiotic components of ecosystems. And although the processes that determine the cycle of substance and energy in lakes and reservoirs have the same nature, their spatial-temporal variability and intensity can vary significantly depending on the characteristics of these water bodies.

Any particular reservoir has individual featureswhich may not cover the entire variety of processes encountered, and often dominant in this type of water object. When comparing lakes and reservoirs, it is important to show that a particular process, one or another factor is more often observed in this water object, compared to the other. In other words, the average values \u200b\u200bof the characteristics that affect the functioning of the ecosystems of these types of inland reservoirs, have significant differences.

Theoretically, the infinite variety of abiotic elements of the ecosystems of sushi water bodies is due to a combination of three main factors: the geographic-hydrographic position of the water branch, the form and size of its bowl and the anthropogenic effect. The interaction of these three main factors determines the hydrological regime of the reservoir with its aqueous, radiation-thermal, sedimentation and hydrochemical components. Interconnection listed factors With individual elements of the hydraulic and hydrochemical mode, it can be represented as a scheme shown in Fig. 2.1.

Fig.2.1. Factors defining the functioning of water ecosystems.

This scheme is equally applicable to both lakes and reservoirs. The exclusion is the connection of the anthropogenic effect and hydrological regime of reservoirs allocated on the diagram. For lakes, except for the relatively minor effect of water selection and reset wastewater The hydrological mode of the lake is practically absent. For reservoirs, as objects created in order to regulate the drain, the water regime control is of fundamental importance in the formation of the hydrological mode and the functioning of the ecosystem.

Each of these factors is manifested in different ways in lakes and reservoirs. Their complex combination leads to the formation of the essential features of the abiotic elements of ecosystems and, thus, the peculiarities of their functioning in these two classes of compared water bodies - lakes and reservoirs.

Given that its primary productivity is the most important characteristic of any ecosystem, the complex of factors presented in the scheme is appropriate to divide into groups external influences, directly or indirectly determining the processes of primary production of organic matter in the reservoir. We consider such groups

energy factors (absorbed solar radiation ecosystem, water temperature),

hydrole-morphological (hydrological mode and morphometric characteristics of the reservoir),

hydrochemical (nutrition of phytoplankton).

Factors of the first of these groups are characterized by pronounced geographic zonality and intra-year variability. The influence of the hydrological regime and the size of the water branch on the productivity is mediated by a large number of dynamic and thermal processes, so its role can be isolated in its pure form only by mathematical modeling of the functioning of ecosystems. Hydrochemical and, especially, morphological factors - avonal and should be considered regardless of the geographical location of the water branch. Conducted according to observations on the water bodies of the world assessing the productivity of continental reservoirs show the leading role of energy factors, which determine more than 70% of the variability of the productivity of lakes and reservoirs of the world. Therefore, it is quite legitimate to talk about the zonality of productivity of water bodies. This, in turn, determines the need for various approaches to the estimates of the trophic state and the process of eutrophing of water bodies located in various geographical zones.

When comparing lakes and reservoirs, the genetic diversity of these objects is extremely important. A wide variety of lakes of the globe is due to the origin of the lake kitlovin, with which their dimensions and form are closely related, and, therefore, certain features of the regime. According to a well-known classification of M.A. Mervukhin, all lakes are divided into dams and boilers. In quantitatively, the pitual lakes are clearly dominated. Among the pitual lakes are the most numerous lakes of glacial origin, which in turn are divided into erosion and accumulative. To the areas of large shifts earth crust Lakes of tectonic origin are usually confined, among which the deepest lakes of the world - Baikal and Tantganica. Water-erosion and water-accumulative lakes prevail in the valleys and delta rivers, near the sea coasts. Failure and volcanic lakes are relatively few.

Even an approximate number of lakes on globe It is practically impossible to determine. According to the famous estimates of R.Tecel, the world is about 10 million lakes, occupying about 1% ground surface . However, there is no doubt that the most numerous group of lakes - lakes of glacial origin. In Sweden among tens of thousands of lakes - about 97% - lakes of glacial origin. This ratio is also characteristic of the North of the United States, Finland, Karelia - those places where the glaciation passed. The most comprehensive modern data bank on the lakes of the world, which includes more than 40 thousand lakes of various continents, was assembled by S.V. Ryanzhin [Ryanzhin, Ulyanov, 2000].

The variety of types of reservoirs is significantly less, since their genesis, in most cases, is determined by the construction of the dam in the river valley. The most reasonable and strict classification of the reservoirs proposed by KKOdelstein is the same principle as for the lakes. According to this classification, all reservoirs are divided into three types: valley, pitual and mixed. According to the most extensive of published lists of the world's reservoirs [Avakyan et al., 1987], 75% of all reservoirs belong to the valley type. It is these reservoirs that we will consider when comparing the features of ecosystems of lakes and reservoirs. The lake-rowing reservoirs prevailing among the pitual reservoirs are formed during the structure of the hydraulic circulation in the source of the river flowing out of the lake, and according to the compared characteristics are very close to lakes.

The genesis of the lakes is closely related to their age, which is determined in the formation and operation of the ecosystem not only over the centuries, but also at present. The lakes' age is determined by geological periods of time, even the youngest lakes are tens of thousands of years (if they do not take into account the small lakes and thermal tundra lakes arising in erosion basins of river valleys). Reservoirs are young reservoirs. Although the reservoirs built in the most ancient times are known, the intensive construction of the reservoir began in the twentieth century and only by the middle of the century these water bodies became the usual element of most natural landscapes. The most intensive construction of reservoirs in all countries was observed between 1950 and 1970. To illustrate, you can bring graphs to increase the number of reservoirs in industrialized north. America and Europe last century.

Fig. 2.2. The increase in the number of reservoirs in North. America and Europe in the 20th century. (By [reservoir ..., 1979]).

By the end of the century, the construction paces of reservoirs slowed down, which is due to a greater extent with the completion of rivers regulation in industrialized countries and the creation of water supply complexes in large urbanized areas of the world (Volga, Dnipro, Tennessee). At the same time, in some developing countries, especially in the regions of the arid climate (Brazil, some countries of Africa, Asia), the pace of construction of reservoirs has even increased, since the economic development of these regions is closely related to the need for guaranteed population, agriculture and industry water.

2.1. Geographical distribution of lakes and reservoirs on the globe.

The distribution of the lakes on the globe is closely related to their origin. The main feature of this distribution is the maximum of the lakes in the belt of the Ice Activities of the Northern Hemisphere. By a sample of 2300 natural lakes, R. Shulling built a graph of the latitudinal distribution of the number of lakes on the globe having a trimodal view. It is difficult to determine how representative the sample of shullling is, but in general, the presented distribution quite corresponds to the distribution of climatic and geological factors of their genesis. All three peaks on the challenge of the Shulling correspond to the areas of the globe rich in water resources. This can be considered the main feature of the distribution of the lakes on the globe, most of which are concentrated in wet areas. According to V. Leisis, 90% of the lakes of the world are concentrated in moderate latitudes. In tropical latitudes, floodplain lakes are dominated in the basins of the largest rivers of tropical belts and small coastal lakes. Some famous lake areas of the semi-diarid climate (Lakes of the Kulundy steppe, the lakes of the Caspiana, Lake Florida) due to the features of the relief can be considered an exception to this general pattern.

The distribution of reservoirs on the globe determine the purpose of their creation. Intensive construction of reservoirs is carried out in the regions developed in business, with high population density (electricity generation, water transport, flooding) and in regions with a clearly pronounced water resource deficit (industrial and communal water supply, irrigation). In the developed and developing countries of the semi-diarrhea climate, the number of reservoirs of reservoirs reaches tens of thousands (Spain, Brazil).

The illustration of this provision shall see the distribution schedules for lakes and reservoirs in the United States and in the European territory of Russia. The distribution of lakes and reservoirs by latitude in the European part of Russia is shown in Fig.2.3.

Fig. 2.3. Distribution of lakes and reservoirs by latitude in the European territory of Russia

A - quantity (by 10 thousand square meters km), b - total area, km 2 (dark columns - reservoirs, light columns - lakes)

The schedule was built according to the Cadastre reservoir of the USSR [Cadastre ..., 1988] and the reference data of the rivers and the Lakes of the USSR [Domanitsky et al., 1971]. In addition to the number of water bodies, the graph of the total area of \u200b\u200bthe water surface of the lakes and reservoirs in the corresponding latitudinal belts is presented. The distribution of lakes and reservoirs in the European territory of Russia has a pronounced opposite direction. The northern maximum of the lakes is due to the wide distribution of small tundra lakes on these latitudes. Maximum on the area is located somewhat south and is associated with the Ice Lakes of the North-West. In the distribution of reservoirs, the maximum of both in the amount and in the total area belongs to the latitudes corresponding to the Black Earth Strip of Russia and the south of Russia, where compared with the northern regions a significantly higher population density and developed agriculture. This confirms the predominance of economic and geographical reasons in the patterns of the distribution of reservoirs.

For the United States, such a schedule was built by K.T.Tornton on a sample of 309 natural lakes and 109 reservoirs (Fig. 2.4). This schedule shows the maximum distribution of the lakes in the glacier region (north of 40 degrees of northern latitude), and the maximum reservoir is essentially south.

Fig. 2.4. Distribution of reservoirs (dark columns) and lakes (light columns) via latitudes in the United States (by K.Tornton).

Most US reservoirs are concentrated in the central, southeastern and eastern districts, areas of intensive development of agriculture and a stress water balance.

The U designation distribution of lakes and reservoirs and on the globe as a whole show the opposite trend. This led to the dominance of various types of landscape and the influence of various geographical factors on the hydroecological regime of these water bodies.

Differences in climatic characteristics of lakes and reservoirs are fully related to the difference in their geographical position. For reservoirs, dominant in a semi-deride climate, the predominance of evaporation over sediments is characteristic. High evaporation leads to direct loss of water, for example, the Sobeno reservoir in the northeast of Brazil annually loses about 2 km 3 of water. . However, despite this, the creation of reservoirs in these regions often performs almost the only possibility of increasing water resources by regulating the extremely uneven river flow. Most of the lakes are located in wet areas with precipitation over evaporation. An interesting aspect of climate differences is noted in the work of K.Tornton, which showed that in the US countries, where most reservoirs are concentrated, cyclonic activity and the wind regime associated with it are more active.

The most important consequence of the differences in the geographical distribution of lakes and reservoirs are the features of their catchment. It is through the catchment, through a river and slope drain, manifests itself, mainly both natural and anthropogenic effect on the reservoir ecosystem. The degree of this effect depends on the magnitude of the external water treatment of the reservoir. The reservoirs almost always dominates the horizontal (river) component of external water exchange. They are characterized by much greater values \u200b\u200bof the coefficient of water exchange. In widely used in the limited literature, the concept of "ecosystem response to external impact" the main meaning is associated with the impact on the reservoir in the form of a river inflow from the catchment. Consideration of the water branch and waterboat as a single system has become a distinctive feature of modern comprehensive limbical research [Drabkov, Sorokin, 1979, changes ..., 1983].

Differences in the catchments of lakes and reservoirs are manifested in landscaped features and in the form of a catchment area. The size and shape of hydrochibors determines the nature of the spatial distribution of the external load on the water, substantially dependent on the position of the reservoir in the pool. The drainage of reservoirs is usually narrow and elongated, ending with a reservoir, in contrast to the drainage of lakes - circular with a reservoir in the center. An important quantitative characteristic of the catchment is its specific value representing the ratio of the area of \u200b\u200bthe catchment to the area of \u200b\u200bthe pond, which, along with climatic characteristics, determines the structure of the water balance of the reservoir.

For reservoirs, the area of \u200b\u200bthe catchment is determined by the choice of the location of the dam of the dam in one or another place of the river network. A comparative analysis of the distribution of the relative number of valve reservoirs and lakes with various sizes of a specific drainage, conducted by KK.EDELStein on a sample of 852 reservoirs [Edelstein, 1991], showed that almost a third of the lakes considered by him have a specific catchment of less than 20, at the same time Time for 90% of valley reservoirs This value is more than 20. According to this indicator, the differences in lakes and reservoirs are manifested very clearly: the specific waterborns of reservoirs on average are much higher than the specific drainage of lakes. It should be noted that, in contrast to landscape characteristics, the shape of the waterborns and their specific value belong to the abonal factors. Landscape features of hydrogenations are associated with the differences described above in their geographical distribution and manifest themselves in the features of the formation of aquatic, chemical drain and drainage of balanced substances.

2.2. Morphological differences of bowls of lakes and reservoirs

The structure of the bowls of water bodies have a deep impact on intake processes, determining the features of the processes of internal water exchange and the associated cycle chemical substances.

Features Kotlovin Lakes and valley reservoirs are determined by their various genesis. Bowls of valley reservoirs are formed in the river valley, but despite the large variety of types of river valleys, due to the geomorphological characteristics of individual land regions, have common patterns. Valley reservoirs are characterized by a large elongation and heteromorphism of the structure of the face, which is always asymmetric with the maximum depth of the dam. The dimensions and capacity of valve reservoirs substantially depend on the choice of dam stem in the river system and the height of the dam, which is manifested in an empirical connection between the water area and the container of valley reservoirs.

The lakes are distinguished by a much larger variety of the buildings of the brand associated with the variety of their genesis. However, the overall line of the structure of their kotlovin can be considered the position of the maximum depth near the lake center.

Morphometric characteristics of the size of the bowls of lakes and reservoirs vary in large limits and do not have fundamental differences. The features of the structure of their bowls are manifested in significant differences in some relative morphometric indicators and in geometric modeling of the shape of the hollow. The reservoirs differ from the lakes a significantly smaller scale of medium depth oscillations, i.e. The ratio of volume to the area (W / F), a greater elongation (L \u003d L / B of CP), where L is the length of the reservoir, the BSR is the average width. At the same time, these differences are enhanced in morphometrically complex valley reservoirs.

To assess the influence of the structure of the bowl of the reservoir on the features of the functioning of the ecosystem and the processes of eutrophing, the shape of the bed seems to be an important morphometric characteristic of water bodies. Two extreme types of this form have the form of a V-shaped and U-shaped section. The value of this characteristic is due to the extreme significance in the eutrophoting of mass exchange processes on the border of water-bottom of the reservoir.

For each horizontal layer selected in the water branch, the area of \u200b\u200bthe water-bottoming zone depends on the shape of the bed. The effect of bottom sediments on this layer is determined by the ratio of the bottom surface in this selected layer to the volume of the layer. This ratio, named by the damage "function of the bottom surface interaction, can be expressed as follows:

(1)

where F. - area of \u200b\u200bthe reservoir to the depth h. , W. - Volume

Changing the concentration of any chemical in the reservoir under the influence of its flow from bottom sediments or, on the contrary, it is defined from the water into bottom sediments as

C. - concentration of substance, S. - a stream of substance from bottom sediments.

Sharing both parts on DW and, given the expression (1), we get

Thus, the rate of change in the concentration of substances in the reservoir under the influence of bottom sediments is determined by the intensity of the thread of the substance and the parameter but characterizing the morphometric features of the reservoir. In the deep-water parts of the v--shaped reservoirs, the value but Significantly less than in the deep-sea parts of water bodies with a U-shaped form, therefore, with other things being equal, the influence of bottom sediments on the chemical composition of the water of the reservoir in the latter will be greater.

The area of \u200b\u200bthe contact zone of water-bottom is extremely important as well for the oxygen regime of the reservoir due to the high activity of the mineralization of the organic matter on the surface of the bottom sediments. In fine water bodies, the rapid formation of anoxia zones under the same conditions for producing and receipt to the bottom of the organic matter is much more likely than in deep.

The degree of cutting of the coastline of reservoirs is determined by the geomorphological features of the terrain and in complex-valve reservoirs can be very large. Statistical comparison of lakes and reservoirs in one of the very common morphometric indicators - the coefficient of the water capacity containing the ratio of the average depth of the reservoir to the maximum, (H / H MAX) showed that the reservoirs differ significantly from the lakes and have smaller average values \u200b\u200band less variability of this indicator [Edelstein, 1991]. Accordingly, in the hydrological mode, the dynamics of the aqueous masses of the reservoir, the role of the size and shape of the bed is much more important than in other aquatic sites of slow water exchange.

For the characteristics of the form of the face, geometrical modeling is used, consisting in comparing the shape of the water branch with known geometric bodies. The quantitative assessment of the proximity of the reservoir form to these bodies is made according to various indicators called form indicators. The lake basins with geometrical modeling are compared with the bodies of rotation having a vertical axis (cone, parabulaoid, semi-celloid and cylinder). Such a comparison made it possible to analyze the relationship of the dynamic processes occurring in the lake, with the structure of its bowl and, first of all, changes in the hydrodynamic stability of the mass of water with an inhomogeneous field of density [Theological, 1960, Homskis, 1969].

The morphological and morphometric features of valve reservoirs predetermined the selection of a truncated trapezoidal prism as a model figure of their form [Edelstein, 1975, Strashkrab, Gnachk, 1989]. Analysis of the effect of such an asymmetric form of the reservoir bowl on dynamic processes, manifested in existence, along with free convection of the longitudinal density circulation of water, shows their fundamental difference from dynamic processes in lakes characterized by long periods of stagnation of water masses. In the dynamics of water, it primarily refers to the emergence and widespread density of density trends in reservoirs, which are relatively rare in the lakes. In the reservoirs of a moderate zone, density flows in reservoirs are connected mainly with differences in density of mineralization and manifest themselves in winter. In the reservoirs of the arid zone, density flows of mudiological origin [Puklakov, 1999, Samolyubov, 1999].

The effect of morphometric features is also manifested in the development of vertical density and chemical stratification of water strata in lakes and reservoirs. Finally, longitudinal differences in dynamic phenomena also differ significantly in water bodies of the compared two classes.

2.3. Features of anthropogenic influence on the lake and reservoir

Reservoirs are water bodies created in order to regulate the river flow, so the main feature of their lakes is that their water regime largely depends on the flow of water flow through the hydraulus.

The main consequence of this regulation is much greater than in the lakes, the scope of intransic fluctuations in the water level. It is important for intole-earth processes, especially in the vegetative period, and for the development of bottom biocenoses, their participation in the functioning of the aquatic ecosystem. On the perimeter of the reservoir, there is a space of a variable width and an area, periodically flooded with water. Such shallow-growing zones on the plain reservoirs are particularly extensive, where they constitute a significant proportion of the area of \u200b\u200bthe water area at NPU. The method of isolating the constant and periodic flooding zones in reservoirs, based on the joint analysis of the water level curves in the reservoir and its batiographic curves was developed by K. K.EDDelstein [Edelstein, 1975]. However, the role of this space in the functioning of the reservoir ecosystem, in the formation of its biological productivity, in the processes of secondary pollution and self-purification of water has not yet received a reasonable assessment.

The second most important consequence of the economic regulation of the water regime is the instability of the hydrodynamic regime, manifested in fluctuations in the flow rate of the stock course, in the appearance of long waves and in the complication of the hydrological structure of the reservoir. Significant environmental significance also reset water from the reservoir. In stratified reservoirs, this affects the nature of the cycle of substances in the seller. The designs of water-based structures are distinguished by significant variety. From the point of view of influence on the hydrological regime of the reservoir the greatest value They have constructions that provide the possibility of selective multi-level reset. This feature fundamentally distinguishes the reservoir from lakes that do not have a depth. In the lakes, the discharge of the water of the hypolimnion is not possible, while in the reservoirs of hydropower plants during the period of stagnation, the water reset will be carried out just from the deep layers.

Another feature of the hydroecological regime of water bodies is associated with anthropogenic influence. Reservoirs are created mainly in densely populated and intensively developing in economic and economic regions. In this regard, they are experiencing, as a rule, a significantly higher anthropogenic load with chemicals. The flow of pollutants of a variety chemical composition It can be both directly in the reservoir and in the reservoirs of the reservoir, i.e. In the hydrographic network of the waterboat of the reservoir. The pollutants come in the reservoir and in the watercourse of the pool, both by concentrated discharges of sewage systems and from dispersed sources due to a flushing of surface waters from contaminated urban and industrial areas, agricultural land, farms and pastures. The flow of pollutants and biogenic elements from the catchment, which determines the chemical load of the reservoir depends both on the physico-geographical features of the catchment, and on the degree of anthropogenic matter, which for reservoirs is usually higher than for the lakes. The anthropogenic factors affecting the chemical load on the reservoirs belongs to their recreational use. The role of this factor in urbanized areas is naturally significant. The creation of both individual reservoirs and hydraulic complexes for water supply of large cities is associated with their intensive use for recreation purposes. An example is the water supply system of Moscow, which includes 12 reservoirs, most of which are widely used for water recreation and amateur fishing by residents of a multi-million city.

A noticeable deterioration in the quality of water is observed in reservoirs in the first years of their existence, when leaching of chemicals from bold soils occurs. Anaerobic conditions in the bottom layers arising in the decomposition of flooded vegetation cover are promoted to the intensive flow of substances into water. This deficit is especially expressed in the reservoirs whose beds were not cleared of vegetation before flooding. Later over time, the duration of which depends on the nature of soils, vegetation, climatic conditions And the intensities of the water exchange, the reservoir ecosystem stabilizes, the bottom is covered with ilical sediments, and the balanced intake processes are no longer different from the lake.

Extremely important circumstance is that the reservoirs have the possibility of targeted regulation of intensity and the orientation of intake processes, which is impossible in lakes without creating special designs. Through the regulation of intolement processes, it is possible to approach the solution of the process of controlling the volume of the substance in the ecosystem of the reservoir and, thereby achieving the most important goal Modern hydroecology - water quality management of reservoirs.

2.4. Comparative characteristics Hydrole-hydraulic mode of lakes and reservoirs

The features marked in the previous section the features of the main factors that determine the functioning of ecosystems of lakes and reservoirs are manifested in the nature of the hydrological and hydrochemical regimes of these reservoirs. After the hydroecological features of the reservoirs of the limites began to pay special attention, several attempts were made to formulate and summarize the fundamental differences between lakes and reservoirs. In our work, this generalization was carried out on hydrological (Table 2.1), hydrochemical (Table 2.2) elements of ecosystems of these water bodies. Naturally, the consequence of the differences between these elements, the ecosystems are distinguished in the development of their biotic parts of the classes of reservoirs. (Table 2.3). The biotic community of the reservoir ecosystem differs from the lake, as a rule, by a low diversity, a relatively clearly pronounced specialization of ecological niches, rapidly selective development. A special period in the formation of a reservoir ecosystem, as a rule, characterized by extremely high productivity, is the period after the flooding of the reservoir bed, when, as a result of intensive leaching of chemicals from flooded soils and decomposition of the organic matter at the bottom of the reservoir, the aqueous masses are enriched with biogenic elements, which leads to abnormal flashes "Flowering" phytoplankton. The duration of this period of the formation of the ecosystem depends on the physico-geographical characteristics of the terrain, the degree of fitness of the bed to flooding.

Table. 2.1.

Comparative characteristics of hydrological regime of lakes and reservoirs.

Characteristics of the water branch	Reservoir
Form Lodge	Extracted, asymmetric along a longitudinal axis with the greatest depth near the dam	Often rounded and more symmetrical relative to the vertical at the point of the greatest depth
Transformation shores	Very intense in the first decades and gradually fading especially slowly in reservoirs of many years of regulation of the drain with the most unstable level	Irregular, episodic only during particularly strong storms
Change coastline	Strong, the littoral zone moves when machined.	Relatively weak, litter position stable
	Mainly by large rivers, penetrates stratified layers and often the flow spreads along the flooded bed	Basically with small small order rivers and diffuse sources. Penetration into stratified layers is weak and scattered.
	Depending on the purpose, it is often very uneven, selective from the surface layer and from the hypolimnion, or integral with high discharges.	Smoothly variable during the year from the surface layer
Level fluctuations	Irregular, intra-year-in-law, exceeding long-term level fluctuations	Intraday small, usually less than perennial
Structure of water balance	Monotony, only stock inlet type with a share of both precipitation and evaporation in external water exchange no more than 25%.	Large variety, including all types of structure and specificity and climate dependent
The coefficient of water exchange	Short, variable. Increases during surface water discharges.	Long, from year to year relatively constant (from one to many years)
Hydrological structure of water masses	Very complicated, multicomponent, especially in morphologically complex reservoirs with temperate water exchange (with a period of water exchange for more than six months). It does not depend on the size of the reservoir and is manifested in the accumulation of genetically and qualitatively different aquatic masses of the lake type and river phases of the drain.	Easy, homogeneous in shallow-water lakes with a small specific water supply, is somewhat complicated in deep and large lakes during the periods of the existence of a thermobar or in highly flowing lakes.
Radiation mode	The horizontal gradient of the extinction of light prevails. Extinction is uneven and often very high in the river and intermediate zone due to the high content of mineral suspensions.	Vertical light gradient prevails. Changeable, but relatively low extinction.
Water temperature	Higher	Usually low due to colder climate
Thermal stratification	Stratification changeable, irregular. It usually does not occur in too shallow river and intermediate zones.	In deep lakes, regular and steady during the summer period.
Water density field and gravitational resistance of water mass	Water density is more horizontal and vertically inhomogeneous. The greatest in the bottom winter aqueous mass and in the bottom density stream (the thermobar is not formed). Constant instability, manifested in seasonal convection and density bottom currents into intermediate periods of mineralization (in plain reservoirs) and torment (in mountain reservoirs).	Horizontally almost homogeneous, the greatest in thermobar. Seasonal instability during periods of partial and complete circulation, replacing gravitational stability during periods of stagnation.

Table 2.2.

Features of the elements of the hydrochemical regime and their consequences in lakes and reservoirs

Mode elements	Reservoir
	High in accordance with the intensive transformation of the shores. Allohton load suspended organic matter moderate	Small, as a common and alcohton suspended organic matter
Weighted substance in water	High and changeable concentration of suspended particles in water with a large proportion of sand and clay mineral particles, relatively large turbidity of water	In the deep layers, lakes are small or very low concentration of suspended substances, in shallow water lakes - clutching, high turbidity and a large proportion of suspended organic matter
Bottom sediments	Large in the upper reaches, the maximum thickness is timed to the flooded line of the hollow, the large seasonal variability of the accumulation rate, climbing and transdimentation during machining, low content of organic matter	Relatively low and constant seasonal accumulation rate, high content of organic matter
Military mineral substances	The inhomogeneity of mineralization is particularly significant in the weakly flowing reservoirs that feed on an unregulated drain, in the period of convection - horizontal, during the period of stagnation - vertical	Insignificant inhomogeneity in freshly gololomic lakes and a substantial vertical in meromictic
	Big, very volatile, often unpredictable	Changeable, but relatively predictable, often moderate
Variability of biogenous concentrations	The horizontal gradient dominates. Depends on the rate of sedimentation and the inflow mode, concentrations decrease with removal from the upwards, uneven internal load	Vertical gradient dominates
Dissolved organic (Ditch)	Allohton sources, uneven, often high concentration, predominate, is dominated by persistent moat.	Allochton and littoral sources, relatively constant content, often high due to labile ditch
Dissolved oxygen	Lower solubility due to higher temperature. Large horizontal variability. Minimum in metalimnion is more common than maximum	Weak horizontal variability. Metalimic maximum is observed more often than in reservoirs

Table 2.3.

Features of the elements of the hydrobiological regime and their consequences in lakes and reservoirs

Communities of aquatic organisms	Reservoir
Phytoplankton	Noticeable horizontal heterogeneity of biomass and species composition. Primary products are limited to high turbidity and content of biogen	Vertical and seasonal heterogeneity prevails. Horizontal inhomogeneity is small.
Zooplankton	Maximum development in a transit (transitional) zone, horizontal heterogeneity is large, the main source of food - weighted deriters with adsorbed ditch	Vertical and seasonal variability prevailing, spotting moderate, main source of food - phytoplankton
Benthos	Low variety with a minimum in the littoral, productivity from low to moderate, in the first years high when flooding ground vegetation	Diversity and productivity moderate to high
Ichthyofauna	Preferably the thermal-loving types of fish, often different from the initial composition, the conditions of spawning deteriorate at a low level, the productivity is high, then decreases	Good spawning conditions, less death of caviar, good conditions for the development of larvae, moderate productivity

Given the identified features of the reservoir, the question of the applicability of indexes, classifications and criteria for the trophic state to reservoirs becomes important. Here, the opinions of researchers are different. Thus, some limle emphasize the need to develop a special type of reservoir ecosystem status, which would take into account the specifics of reservoirs. At the same time, in the already mentioned international program for eutrophication, the estimates of the trophic state of reservoirs and lakes were separated. This opinion is divided by a number of domestic lymnologists, which believe that the intensity of photosynthesis in any reservoir and even fluctuates in the same range, so it should not separate objects [Barnes, 1961, Lebedev, 1988]. The inspection of a number of classifications on lakes and reservoirs has shown that they are quite adequate in all indicators, with the exception of transparency, which in the reservoirs overestimated the trophic level. The reason for this is seen in a higher content of mineral (nefitoplankton) turbidity in reservoirs. In addition to transparency, it is necessary to note some more features of the reservoirs that need to be borne in mind when applying classifications and indices. First, due to the pronounced longitudinal heterogeneity of the composition of water in the reservoir, the longitudinal heterogeneity of the abiotic and biotic elements of the ecosystem and, accordingly, the trophic conditions is often observed. Therefore, when applying the trophy indicators to characterize the entire reservoir, their spatial averaging is necessary, taking into account the areas and volumes of reservoirs. Secondly, characteristic of reservoirs and rarely observed density flows can lead to the discharge of biogenic elements entering them without mixing with the main water mass reservoirs. Finally, Lind et al. Revealed that in the reservoirs they surveyed were observed inadequate correspondence between the content of the total phosphorus and the trophic state. These features caused attempts to develop special trophic state indices applicable solely for reservoirs and giving a more adequate estimate than ordinary generally used. The experience of developing a special index for assessing the trophic state of the reservoirs, proposed for Cascade of the Tennessee by J.Koh, deserves attention. Having allocated deep reservoirs in the R.Teysci's deep reservoirs in the R.Teyssey tributary system, and relatively shallow water, located directly to the R.Teessey, J.Koh rightly suggested that for these various types of reservoirs, individual trophic state indices should be based on various Indicators. For reservoirs on the tributaries, the koch indicator is the sum of the relative value of the concentration of chlorophyll "A" and the average of the three relative values \u200b\u200bof the concentrations of biogenic elements: inorganic carbon (alkalinity), dissolved inorganic nitrogen and total phosphorus. These relative concentration values \u200b\u200bare defined as the ratio of the difference of the actual average value of the corresponding concentration in the reservoir under consideration and its minimum value in the entire sample to the total range of changes in the corresponding relative values \u200b\u200bin all surveyed reservoirs. The same principle was used in the development of a trophic indicator for reservoirs on the R.Teessei (actually cascading). The index is equal to the sum of the two terms. The first is the half as the values \u200b\u200bof the concentration of chlorophyll "A" and the area of \u200b\u200bdistribution of macrophytes in the reservoir, the second is the average value of the following relative values: the period of water exchange, the depth of visibility of the section of the section, the relative area of \u200b\u200bshallow and relative elongation. However, as J.Ko. The applicability of these indexes should be limited only by reservoirs that have similar limbological and water traits with reservoirs of the Cascade of Tennessee, which essentially makes these indices individually for the cascade under consideration.

Considering the applicability of the most common index - the Carlson index - to the assessment of the trophic state of the reservoir, V.Woker proposed to modify the Carlson equation for transparency, including an additional parameter that characterizes the so-called nefitoplanteal turbidity. Equation of V.Woker has the form

Where SD. - depth of visibility of the disk of the sect, m, α - an additional parameter characterizing the so-called nonfitoplank turbidity due to the component of the suspension in a water branch that is not associated with phytoplankton, 1 / m. Magnitude α V.Wero offers to calculate according to empirical formulas, depending on the depth of the reservoir, the period of its water exchange and the latitude of the terrain, where it is located.

where h is the depth of the reservoir, T is a period of water exchange, φ - the latitude of the locality where the reservoir is located.

These dependencies were obtained by V.Wero to observations on the reservoirs of the Midwest and the South of the United States, therefore are regional importance.

Individual indexes for assessing the trophic state of individual cascades or systems of reservoirs certainly allow you to more accurately appreciate the changes occurring in the ecosystems of these reservoirs, however, for their development, detailed comprehensive limited studies are needed during a perennial period that are still very rare. As showed a wide experience of using the classifications of a trophic state, in indicative estimates, the use of the methods developed for lakes to determine the trophic state is quite acceptable for reservoirs, subject to attention to the peculiarities of using the corresponding states of these water bodies.

Abstract of dissertation.

Biotic I. abiotic Laws of I. features ecosystems elements reservoir and lakes [Mordhai-Bolt, ...

Patterns and factors of sustainability of freshwater ecosystems to anthropogenic pollution

Abstract of dissertation.

Biotic I. abiotic Laws of I. features Functioning freshwater ecosystems Russia in ... content of natural substances ( elements) in surface waters ... research on limbory reservoir and lakes [Mordhai-Bolt, ...

Utch e t Forecast water quality in the reservoir and in the lower baine of the Boguchanskaya HPP

Document

Number of others elements in... ecosystemsand with natural conditions Waterboards. In this process participate abiotic ... reservoir. Novosibirsk: Science, 1973. P. 78-118. Vinberg G.G. General features Production Process in Narlaganic lakes ...

In its structure and the principle of action, natural ecosystems are open systems. An integral condition for their functioning is to provide and receive various types of energy and resources. Without this, the eternal cycle of the Earth sooner or later would have been exhausted. In addition, the ecosystem is considered only the system that is capable of exist without external intervention. All necessary for operation it produces itself. To maintain continuous flow of substances in any single ecosystem, there must be functionally different groups of living organisms.

In the size of the occupied territory, as well as the number of elements involved in the cycle of alive and inanimate nature distinguish systems of four types. At the very bottom there is a microecosystem, the simplest example of which can serve as a drop of human blood or water from the river. Next follows the mesoecosystems. This category includes the lake ecosystem, reservoir, prairie, steppe or, for example, forests. In third place are macroecosystems, which are entire continents and oceans. And the planet Earth itself is considered the largest ecosystem itself, more precisely - all life on it. This system is called global.

Ecosystem structure

The main source of energy in the lake is sunlight. When the rays go through the thickness of water, most of the energy absorbs plankton to then use it for photosynthesis processes. The remaining light is gradually absorbed by the water itself. Therefore, the illumination at the upper levels is always big, and closer to the bottom decreases. Any sufficiently large lake ecosystem has the so-called compensation level. This is the depth that reaches the amount of light as minimally necessary plants. Photosynthesis in such plants slows down to balance other indicators - breathing and food consumption.

The location of the compensation level directly depends on the properties of water, its purity and transparency. It is a particular conventional dividing line. Above it, plants produce an excess amount of oxygen, which then use other living organisms. And below the separation line of oxygen, on the contrary, too little. Its main part falls on the depth of other, the upper layers of water. Thus, only those living organisms that may be inhabited below the compensation level. minimum quantity oxygen.

General distribution of inhabitants

It is obvious that at the upper levels of the ecosystem of the lake set down much more variety of species than in the bottom zone. This fact Defended by more favorable conditions for life, the amount of food, heat and oxygen in shallow sectors. There are inhabited by rooted lilies, reeds, reeds, graon.

They, in turn, serve as a shelter for insects and arthropods, worms, mollusks, headastrics. Many species of fish are also found here. The smallest arthropods, for the existence of which requires a large amount of light, live near the surface itself. Here it grows freely floating rock.

At its lower levels, the lake ecosystem becomes a habitat for all sorts of renders that feed on the extremely remains of animals and plants. Many predatory species of fish are also inhabited here, such as pike and perch, and some invertebrate organisms. These species or feed down from the upper layers of water are dead creatures or hunt each other.

Effect of pollution for lake ecosystems

One of the most important natural elements for such systems is phosphorus. The total natural content of this substance in lake water depends on its quantity, but human activity leads to a significant increase in concentration. The main reasons should be attributed to the lake draining excessive use of fertilizers, which are then washed off by rains and underground flows. All this brings the excessive amount of phosphorus into the ecosystem.

As a result, the structure and productivity of the wellland system is disturbed: the number of plankton begins to grow rapidly, from which water acquires a muddy-greenish tint. The lake begins to "bloom", but it is only the first stage. Next, it is contaminated with water elements, water becomes less saturated oxygen and sunlight (Plankton in huge quantities absorbs what other inhabitants should have been obtained). The latter violates the activities of the reasons, which is why the water is filled with slowly rotting the remains. At the final stage of the plant begin to produce toxins, causing mass death of fish.

Another type of pollution, due to which the lake ecosystem is essential - thermal. At first glance, it does not seem serious: no chemicals add to water. But after all, the normal functioning of the system depends not only on the composition of the medium, but also on temperature. Its increase also capable of provoking the growth of plants, which launches a slow but faithful disastrous reaction. In addition, individual types of fish and invertebrates are adapted to life in narrow temperature framework. Increased or decrease in temperature in this case slows down the growth of organisms or kills them.

This type of pollution arises as a result of human industrial activity. For example, such that uses lake water to cool the turbines at factories and power plants.