ten percent rule
R. Lindemann (1942) formulated the law of the pyramid of energies, or the rule 10 %:
from one trophic level of the ecological pyramid it passes to another, its higher level (along the "ladder" producer - consumer - decomposer), on average, about 10% of the energy received by the previous level of the ecological pyramid.
In fact, the loss is either somewhat smaller or somewhat larger, but the order of the numbers is preserved.
Reverse flow associated with consumption of substances and produced top level the ecological pyramid of energy with its lower levels, for example, from animals to plants, is much weaker - no more than 0.5% (and even 0.25%) of its total flow, so it is not necessary to talk about the energy cycle in the biocenosis.
Along with useful substances from one trophic level to another, “harmful” substances also enter. However, if a useful substance, with its excess, is easily excreted from the body, then the harmful one is not only poorly excreted, but also accumulates in the food chain. This is the law of nature, called the rule of accumulation of toxic substances (biotic amplification) in the food chain and fair for all biocenoses.
In other words, if the energy during the transition to more high level ecological pyramid is lost tenfold, then the accumulation of a number of substances, including toxic and radioactive, increases in approximately the same proportion, which was first discovered in the 50s at one of the plants by the Atomic Energy Commission in the state of Washington. The phenomenon of biotic accumulation is most clearly demonstrated by persistent radionuclides and pesticides. In aquatic biocenoses, the accumulation of many toxic substances, including organochlorine pesticides, correlates with the mass of fats (lipids), i.e., it clearly has an energy basis.
In the mid-1960s, a seemingly unexpected report appeared that the pesticide dichlorodiphenyltrichloroethane (DDT) had been found in the liver of penguins in Antarctica, a place extremely remote from its regions. possible application. End predators, especially birds, suffer greatly from DDT poisoning, so the peregrine falcon has completely disappeared in the eastern United States. Birds were found to be the most vulnerable due to DDT-induced hormonal changes affecting calcium metabolism. This leads to thinning of the egg shell, and they break more often.
Biotic accumulation occurs very rapidly, for example, in the case of the pesticide DDT, which got into the water of swamps during many years of pollination in order to reduce the number of unwanted insects on Long Island. For this case, the content of DDT in ppm (according to Yu. Odum) is given below for the following objects:
water…………………………………0.00005
plankton ……………………………….. 0.04
planktivorous organisms………………….0.23
pike (predatory fish)………………………..1.33
needle fish (predatory fish)…………………….2.07
heron (feeds on small animals)………… 3.57
tern (feeds on small animals)………… 3.91
herring gull (scavenger)………………..6,00
merganser (bird, feeds on small fish)……….. 22.8
cormorant (feeds on large fish) ……………… 26.4
Insect control specialists "prudently" did not apply concentrations that could be directly lethal to fish and other animals. Nevertheless, over time, it was found that the concentration of DDT in the tissues of fish-eating animals is almost 500 thousand times higher than in water. On average, as in the above example, the concentration of a harmful substance in each subsequent link of the ecological pyramid is about 10 times higher than in the previous one.
The principle of biotic amplification (accumulation) must be taken into account in any decisions related to the entry of relevant contaminants into natural environment. It should be borne in mind that the rate of change in concentration may increase or decrease under the influence of some factors. Thus, a person will receive less DDT than a bird that eats fish. This is partly due to the removal of pesticides during fish processing and cooking. In addition, the fish are in a more dangerous position, because they receive DDT not only through food, but also directly from the water.
Any compound that pollutes the natural environment can be absorbed by living organisms. In this way, it is included in the trophic webs of ecosystems, participates in the cycle of substances, having a harmful effect on living organisms.
All living beings (of course, to varying degrees) have the ability to accumulate in their bodies any substances that are biologically weakly or completely non-degradable. This circumstance gives rise to biological phenomena that complicate the process of pollution of each ecosystem. Indeed, organisms that accumulate toxic substances serve as food for other animals, which then accumulate them in their tissues.
Thus, the infection of the entire food chain of the ecosystem gradually occurs, the beginning of which was laid by the primary producers, “pumping out” the pollutants scattered in the biotope. The accumulation of toxic substances in living organisms increases at each subsequent trophic level. In all cases, predators at the very end of the food chain are the owners of the highest level of infection.
For example, Miettinen (cited by F. Ramad, 1981) showed that the inhabitants of Lapland received doses of radiation (from 90 Sr and 137 Cs) 55 times greater than the inhabitants of Helsinki. He considered the movement of these radioactive elements in the following chain:
The content of radioactive strontium and cesium in lichens is high, which is associated not only with the physiological characteristics of these organisms, but also with the nature of the tundra soils. The soils of the tundra, which are very poor in nutrients and minerals, quickly assimilate strontium and cesium, which are close in their chemical properties to potassium and calcium. The concentration of strontium and cesium in lichens is several thousand times higher than in tundra soils. A new accumulation of radioactive substances occurs in the body of deer that feed on lichens, while Laplanders are poisoned by eating deer meat and milk. In herbivores, the concentration of radioactive cesium was 3 times higher than in lichens, and in the tissues of Laplanders (carnivores) it was contained 2 times more than in deer meat.
In 1953, in one of the fishing villages that stood in Minamata Bay, an epidemic of a mysterious disease broke out. The disease was not contagious, but affected entire families. Residents began to experience nervous disorders: agitation, irritability, inability to concentrate, depression, narrowing of the field of vision, loss of hearing, speech, mind, unsteady gait, etc. Of the 116 officially registered cases, 43 had a fatal outcome, and the survivors had all of the above syndromes. However, Japanese doctors who studied the history of this epidemic estimated the real number of sick people to be many hundreds. In this village, even domestic cats differed in their peculiar behavior. Some of them threw themselves into the water - a behavior not typical of an animal known for its rabies. The disease was named Minamata disease. It was observed twice in Japan: in 1953 in Minamata Bay and in 1965 in the Niigata area.
The cause of the disease was - and this is quite obvious - the presence of a pathogenic or toxic element in the food of the inhabitants of the bay and their domestic animals. A thorough examination carried out between 1956 and 1959 showed that the source of the disease was a fish from Minamata Bay.
In 1962, methylmercury was found in the wastewater of the plant near the bay. In 1965, a similar disease in the Niigata region, located far from Minamata, was also caused by methylmercury. This time, 5 out of 30 seriously ill people died. All of them ate fish caught in the Agano River, into which sewage from the Shova Denko plant, which synthesizes acetaldehyde (methylmercury), fell.
Today, it is clear that the only cause of Minamata's "environmental disease" is methylmercury. The appearance of the first symptoms of this disease was noted sometimes many years after eating fish and marine animals contaminated with this substance, and serious congenital anomalies were found in children born to healthy women from the Minamata and Niigata regions.
The considered phenomena illustrate the biological accumulation (concentration) of toxic substances in food chains. The accumulation by living organisms of a number of chemically indestructible substances (pesticides, radionuclides, etc.), leading to a biological enhancement of their action as they pass through biological cycles and through food chains, is called "biological amplification rule". In terrestrial ecosystems, with the transition to each trophic level, there is at least a 10-fold increase in the concentration of toxic substances. In aquatic ecosystems, the accumulation of many toxic substances correlates with the mass of fats (lipids) in the body of marine life.
Rice. 5.6. Seasonal changes in the biomass pyramids of a lake (on the example of one of the lakes in Italy): numbers - biomass in grams of dry matter per 1 m 3
Seeming anomalies are devoid of pyramids of energies, which are considered below.
5.1.2.3. Pyramid of energies
The most fundamental way to reflect the relationships between organisms of different trophic levels and the functional organization of biocenoses is the energy pyramid, in which the size of the rectangles is proportional to the energy equivalent per unit of time, i.e., the amount of energy (per unit area or volume), passed through a certain trophic level during the accepted period (Fig. 5.7). To the base of the pyramid of energy, one more rectangle can reasonably be added from below, reflecting the flow of solar energy.
The pyramid of energies reflects the dynamics of the passage of a mass of food through the food (trophic) chain, which fundamentally distinguishes it from the pyramids of abundance and biomass, which reflect the statics of the system (the number of organisms at a given moment). The shape of this pyramid is not affected by changes in the size and intensity of the metabolism of individuals. If all sources of energy are taken into account, then the pyramid will always have a typical shape (in the form of a pyramid with the top up), according to the second law of thermodynamics.
Rice. 5.7. Energy pyramid: numbers - the amount of energy, kJ-m -2 r -1
Rice. 5.8. Ecological pyramids (according to Y. Odumu). Not to scale
Energy pyramids allow not only to compare different biocenoses, but also to identify the relative importance of populations within the same community. They are the most useful of the three types of ecological pyramids, but the data to build them is the most difficult to obtain.
One of the most successful and illustrative examples of classical ecological pyramids are the pyramids depicted in Fig. 5.8. They illustrate the conditional biocenosis proposed by the American ecologist Y. Odum. The "biocenosis" consists of a boy who eats only veal and calves who eat only alfalfa.
5.1.3. Patterns of trophic turnover in the biocenosis
Living organisms for their existence must constantly replenish and expend energy. In the food (trophic) chain, network and ecological pyramids, each subsequent level, relatively speaking, eats the previous link, using it to build its body. The trophoenergy connections of the plant and animal community in the form of a simplified scheme of flows on the example of the biocenosis of the Rybinsk Reservoir are shown in fig. 5.9.
The main source of energy for all life on Earth is the Sun. From the entire spectrum of solar radiation, reaching earth's surface, only about 40% is photosynthetically active radiation (PAR), which has a wavelength of 380–710 nm. Plants absorb only a small part of PAR during photosynthesis. Below are the shares of assimilable PAR (in %) for different ecosystems.
Rice. 5.9. Scheme of energy flows in the food web of biocenosis (according to N. V. Buturin, A. G. Poddubny): figures - annual production of populations, kJ / m 2
Ocean……………………………………up to 1.2
Tropical forests…………………………..up to 3.4
Sugar cane and corn plantations
(under optimal conditions) …………………….. 3-5
Experimental systems with conditioned environmental conditions for all indicators (for short
periods of time)…………………………..8-10
On average, the vegetation of the entire planet…………0.8–1.0
Plants are the primary sources of energy for all other organisms in the food chain. With further transitions of energy and matter from one trophic level to another, there are certain patterns.
5.1.3.1. ten percent rule
R. Lindemann (1942) formulated the law of the pyramid of energies, or the rule 10 %:
from one trophic level of the ecological pyramid it passes to another, its higher level (along the "ladder" producer - consumer - decomposer), on average, about 10% of the energy received by the previous level of the ecological pyramid.In fact, the loss is either somewhat smaller or somewhat larger, but the order of the numbers is preserved.
The reverse flow associated with the consumption of substances and the energy produced by the upper level of the ecological pyramid of energy by its lower levels, for example, from animals to plants, is much weaker - no more than 0.5% (and even 0.25%) of its total flow, therefore, to say about the cycle of energy in the biocenosis is not necessary.
5.1.3.2. Biological amplification rule
Along with useful substances from one trophic level to another, “harmful” substances also enter. However, if a useful substance, with its excess, is easily excreted from the body, then the harmful one is not only poorly excreted, but also accumulates in the food chain. This is the law of nature, called the rule of accumulation of toxic substances (biotic amplification) in the food chain and fair for all biocenoses.
In other words, if energy is lost tenfold during the transition to a higher level of the ecological pyramid, then the accumulation of a number of substances, including toxic and radioactive ones, increases in approximately the same proportion, which was first discovered in the 50s at one of the plants by a commission on nuclear power in Washington state. The phenomenon of biotic accumulation is most clearly demonstrated by persistent radionuclides and pesticides. In aquatic biocenoses, the accumulation of many toxic substances, including organochlorine pesticides, correlates with the mass of fats (lipids), i.e., it clearly has an energy basis.
In the mid-1960s, a seemingly unexpected report appeared that the pesticide dichlorodiphenyltrichloroethane (DDT) had been found in the liver of penguins in Antarctica, a place extremely remote from areas of its possible application. End predators, especially birds, suffer greatly from DDT poisoning, so the peregrine falcon has completely disappeared in the eastern United States. Birds were found to be the most vulnerable due to DDT-induced hormonal changes affecting calcium metabolism. This leads to thinning of the egg shell, and they break more often.
Biotic accumulation occurs very rapidly, for example, in the case of the pesticide DDT, which got into the water of swamps during many years of pollination in order to reduce the number of unwanted insects on Long Island. For this case, the content of DDT in ppm (according to Yu. Odum) is given below for the following objects:
water…………………………………0.00005
plankton ……………………………….. 0.04
planktivorous organisms………………….0.23
pike (predatory fish)………………………..1.33
needle fish (predatory fish)…………………….2.07
heron (feeds on small animals)………… 3.57
tern (feeds on small animals)………… 3.91
herring gull (scavenger)………………..6,00
merganser (bird, feeds on small fish)……….. 22.8
cormorant (feeds on large fish) ……………… 26.4
Insect control specialists "prudently" did not apply concentrations that could be directly lethal to fish and other animals. Nevertheless, over time, it was found that the concentration of DDT in the tissues of fish-eating animals is almost 500 thousand times higher than in water. On average, as in the above example, the concentration of a harmful substance in each subsequent link of the ecological pyramid is about 10 times higher than in the previous one.
The principle of biotic amplification (accumulation) must be taken into account in any decisions related to the release of the corresponding pollutants into the natural environment. It should be borne in mind that the rate of change in concentration may increase or decrease under the influence of some factors. Thus, a person will receive less DDT than a bird that eats fish. This is partly due to the removal of pesticides during fish processing and cooking. In addition, the fish are in a more dangerous position, because they receive DDT not only through food, but also directly from the water.
5.2. Species structure of biocenoses
The species structure is the number of species that form a biocenosis, and the ratio of their numbers. Accurate information about the number of species included in a particular biocenosis is extremely difficult to obtain because of microorganisms that are practically unaccountable.
The species composition and saturation of the biocenosis depend on environmental conditions. On Earth, there are both sharply depleted communities of polar deserts, and the richest communities of tropical forests, coral reefs, etc. The richest in species diversity are the biocenoses of tropical rainforests, in which there are hundreds of species of phytocenosis plants alone.
Species that prevail in number, mass and development are called dominant(from lat. dominantis- dominating). However, among them are edificators(from lat. edificator- builder) - species that, by their vital activity, form the habitat to the greatest extent, predetermining the existence of other organisms. It is they who generate the spectrum of diversity in the biocenosis. So, spruce dominates in a spruce forest, spruce, birch and aspen dominate in a mixed forest, and feather grass and fescue dominate in the steppe. At the same time, spruce in the spruce forest, along with dominance, has strong edificatory properties, expressed in the ability to shade the soil, create an acidic environment with its roots, and form specific podzolic soils. As a result, only shade-loving plants can live under the canopy of spruce. At the same time, in the lower layer of a spruce forest, blueberries, for example, can be dominant, but they are not edificators.
Before discussing the species structure of the biocenosis, attention should be paid to the principle of L. G. Ramensky (1924) - G. A. Gleason (1926) or continuum principle:
wide overlap of ecological amplitudes and dispersal of population distribution centers along the environmental gradient lead to a smooth transition from one community to another, therefore, as a rule, they do not form strictly fixed communities.N. F. Reimers opposes the principle of continuum principle of biocenotic discontinuity:
species form ecologically defined system aggregates - communities and biocenoses that differ from neighboring ones, although relatively gradually passing into them.
5.2.1. Relationships between organisms
5.2.1.1. Competition
Competition occurs when the interaction between two or more individuals or populations adversely affects the growth, survival, fitness of each individual, and/or the size of each population. Basically, this happens when there is a lack of any resource they all need. Competition can be between individuals of the same species (intraspecific) or different types(interspecific), both of which are important to the community. It is believed that competition, especially interspecific competition, is the main mechanism for the emergence of biodiversity.
It is beneficial for each population to use every opportunity to protect itself from competition with other species. Natural selection helps individuals occupying inaccessible areas in space ecological niches, and thus leads to less overlap in resource consumption and more niche diversity. Thus, competition affects the size of the realized niche, which in turn is a factor affecting the species richness of the biocenosis.
Intraspecific competition. The available resources are consumed by individuals of the species unequally (Fig. 5.10, A). Those individuals that use a given resource in the marginal, but less contested places of its gradient, have a higher individual fitness than individuals that consume the resource in its optimum zone, where competition is especially strong.
During the period of population growth, the second individuals use optimal resources. With an increase in its density, the advantages of the former decrease due to intraspecific competition. At the same time, favorable conditions are created for "deviating" individuals who use a less contested resource not in the optimal zone. Thus, the diversity of resources and habitats mastered by this population as a whole increases. Consequently, intraspecific competition contributes to the expansion of the niche and the approach of the realized niche to the fundamental one (see Section 5.4). However, the decrease in the availability of the resources themselves causes the exact opposite reaction.
Rice. 5.10. Changes in the niche width during intraspecific (a) and interspecific (b) competition (according to P. Giller): 1– low population density; 2
- high population density. Arrows - direction of change
Interspecies competition. Individuals of a certain species that consume marginal resources cannot use them as efficiently as representatives of other species for which these resources are optimal. Therefore, the area of overlap between niches decreases so that niches become narrower as specialization progresses. As a result, the population size of one or more competing species is also reduced (Fig. 5.10, b). Competition adversely affects all species using the same limited resource, and at the same time and in the same place, potentially causing competitive exclusion of some species according to the principle of G. F. Gause (Fig. 5.11).
With the joint cultivation of two types of ciliates in a single nutrient medium, the species 1
appears to be more competitive in capturing food than the species 2.
After 5–6 days, the abundance of the species 2
begins to decrease, and after about 20 days this species almost completely disappears, i.e., its competitive exclusion occurs. View 1
reaches the stationary phase of growth later than when grown in a separate culture. Although this species is more competitive, it is also negatively affected by competition.
Rice. 5.11. The increase in the number of two types of ciliates in one culture (in experiments G. Gause)(By F. Dre): a– when growing species separately; b– when grown together in a common environment
IN natural conditions a less competitive species rarely disappears completely - it simply decreases greatly, but sometimes it can increase again before an equilibrium state is established. The principle of competitive exclusion by G. F. Gause was subsequently repeatedly confirmed in animals. Thus, with an increase in species diversity as a result of interspecific competition, there is a greater division of niches, and the realized niches of interacting species are proportionally reduced. When species are very similar, they are competitively excluded.
5.2.1.2. Predation
In many existing natural communities, there is a strong overlap in resource consumption niches, which, however, does not lead to the competitive exclusion of species described earlier. The reason for this may be either an unlimited resource (for example, in terrestrial biocenoses no one experiences a lack of oxygen), or the presence of some external factor that keeps the number of potentially competing populations of coexisting species below the level allowed by the capacity of the environment.
An important mechanism for creating a community structure, an alternative to the mechanism of resource sharing through competition, is predation. Thus, if there is a significant mortality due to predation in the population of the most competitive or numerous species, the competitive exclusion of other species will be stopped for an indefinitely long time. In this case, a stronger overlap of niches and, consequently, a local increase in species diversity is possible.
Predation is a difficult and time-consuming process. During active hunting, predators are often exposed to dangers no less than their victims. Many predators themselves die in the process of interspecific struggle for prey, as well as from starvation. There are known cases of the death of lionesses during a collision with elephants or wild boars. Only the fastest and strongest predators are able to spend the necessary time in search of prey, to pursue the prey at a great distance. The less energetic are doomed to starvation.
Predation affects the dynamics and spatial distribution of the prey population, which in turn affects the structure and functions of the community (biocenosis) up to their catastrophic change. At the same time, in terrestrial systems, the complete destruction of plants is rare and mostly non-selective (for example, a locust raid).
Most of the evidence supporting the theory of the role of predation is associated with interactions at the trophic level. The effects of grazing on the yield of above ground parts of plants are not predictable, but it can change the competitive balance between the eaten plant and other species. Grazing also reduces the number of seeds.
Eating seeds and fruits by some primary consumers leads to changes or regulation of the species composition of plant communities. Experiments in which the artificial removal of individual species was carried out showed that eating seeds by ants or rodents increases the species diversity in the biocenosis.
Predation does not always increase diversity at lower trophic levels. While predators may reduce prey population density, this does not necessarily reduce resource consumption, a condition necessary for increased species diversity. In some cases, the weakening of intraspecific competition can activate the species and its reproduction, which in turn will increase the use of the resource. Predation at one trophic level can lead to a "cascading" effect at other levels and cause a decrease in diversity in the biocenosis as a whole.
5.2.1.3. Conjugate fluctuations in the abundance of predator and prey
As a rule, the predator cannot completely exterminate the prey. In most cases, coupled (coordinated among themselves) fluctuations in the number of both populations are observed. One of the most famous and repeated examples in the literature describes the cycle of fluctuations in the number of hare and lynx (Fig. 5.12). At the same time, the main question is who controls whose numbers, whether the predator is the prey, or vice versa.
It is reliably established that populations of hares reach a peak in abundance every 9 years; following this, lynx populations also peak. However, then the number of hare populations is sharply reduced. Initially, this pattern was explained by the fact that lynxes eat too much food (hares) at a certain moment, exceeding the supporting capacity of the environment, which leads to a decrease in the number of the lynx itself, and the whole cycle repeats itself.
Later, in regions where the lynx was exterminated, exactly the same cyclical change in the number of hares was found. Thus, it was found that the number of hares (food resource) controls the number of lynx, and not vice versa.
Based on the foregoing, we can conclude that the main mechanism that creates the structure of communities and biocenoses is competition, and predation only regulates species richness in individual cases. At the same time, as follows from Fig. 5.12, the change in the number of predators lags behind fluctuations in the prey population, which applies primarily to specialized predators that cannot switch to other types of food when the number of the main food species decreases (or switch to a small extent and with a delay). And, on the contrary, the abundance of alternative food for the predator even stabilizes the number of prey. This is probably why sharp outbreaks of abundance are not characteristic of complex biocenoses, such as tropical forests.
Since neither competition nor predation can fully explain all cases of the formation of the species structure of biocenoses known in wildlife, scientists have attempted to find some other mechanism that generalizes all the options. An important condition is the degree of severity (or, on the contrary, favorableness) of the physical environment, i.e., the totality of abiotic factors.
It has been established that under very severe environmental conditions, the number of populations falls below the levels at which they compete. Based on this conclusion and taking into account that under the most favorable abiotic factors, the population density decreases under the influence of predators, J. Connell proposed a scheme shown in Fig. 5.13. In accordance with it, in the mild conditions of the tropics, the main thing is to resist herbivorous organisms, and with increasing latitude, the main thing is to counteract competition.
The principle of operation of the laws of the minimum by J. Liebig on the scale of communities and biocenoses was established by A. Tineman (1926) as the law of action of factors:
Rice. 5.13. Scheme of interaction between the mechanisms of organization of biocenosis (according to J. Connell): 1– population size; 2
– mortality caused by unfavorable abiotic environmental factors; 3
– mortality due to predation; A- populations, the number of which is limited by unfavorable physical environmental factors; B– populations whose numbers are limited by intense predation
"General ecology" - Number. The law of universal connection of objects and phenomena. Subject and main sections of modern ecology. The active part of the biosphere, represented by living organisms. Transition to the stage of the noosphere. Concepts of biosphere and noosphere. Ecocentric approach. The term "ecology" was introduced into scientific circulation in 1879 by a German biologist.
"Prospects for the development of ecology" - It is required to develop a "road map". Encouraging investment in conservation rather than energy production. Stimulation of voluntary business commitments. Regulation of the destruction of toxic waste. Stimulating the timely implementation of environmental standards. Creation of a national system of "green" economic indicators.
"Theoretical foundations of ecology" - Biosphere as an ecosystem. Fundamentals of ecology. Plots. Factors of human activity. Environmental indicators. Basics. Protective covers. Living matter. Participation chemical elements within organisms. The law of tolerance. Living environments. Macroecosystems. Heterotrophs. Air temperature. The subject of ecology.
"Fundamentals of Ecology" - Carps were launched into the reservoir. Organisms. Assignments to the topic "Dependence of organisms on environmental factors." Scheme of action environmental factor. Basic concepts. Tasks for self-control. A population is a collection of individuals of the same species. Infusoria-shoes were placed in a closed test tube. Fundamentals of ecology. Components of the biocenosis.
"The subject of ecology" - Modern stage. The concept and subject of ecology. Soil degradation. Patterns of development of the biosphere. Population change. Ecosystems. Protection and rational use of subsoil. Dynamic indicators. Ecological functions of the atmosphere. Succession. Ecosystem productivity. Stage of agrarian civilization.
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RULE OF BIOLOGICAL STRENGTH The accumulation by living organisms of a number of chemical non-destructive substances (pesticides, radionuclides, etc.), leading to a biological enhancement of their action as they pass through biological cycles and through food chains. In terrestrial ecosystems, with the transition to each trophic level, there is at least a 10-fold increase in the concentration of toxic substances. In aquatic ecosystems, the accumulation of many toxic substances (for example, chlorine-containing pesticides) correlates with the mass of fats (lipids). May cause mutagenic, carcinogenic, lethal and other effects. In addition, such contaminants can form other toxic substances in environment. So far, the only possible way to prevent them is their correct use in the national economy, followed by their removal from the life support system of the environment.
Watch value BIOLOGICAL STRENGTH RULE in other dictionaries
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Unconditional, well-meaning (obsolete), noble, pious (obsolete), important, great, supreme, ........
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As a rule adv.- 1. As usual. 2. Use. How introductory phrase, indicating that the appropriate action is for smb. established, ordinary; as usual.
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Rule cf.- 1. A position expressing a certain regularity, a constant ratio of some. phenomena. 2. A principle serving as a guide in smth. // Starting position, setting, ........
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Balance Golden Rule- the rule of drawing up a balance sheet, according to which long-term investments must be provided with long-term capital, and first of all own, and working capital ........
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Explanatory Dictionary of Ushakov
The Golden Rule of Banks — -
loans and
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- the banking principle of matching the timing of transactions related to both assets and liabilities. Otherwise, it may lead to a lack of cash, funds.
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The Golden Rule of Conducting Liquid Transactions— - banking
the principle of coincidence of the timing of transactions related to both assets and liabilities; in the event of a mismatch occurs
shortage of cash, funds.
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The Golden Rule of Conducting Liquid Transactions— banking
the principle of coincidence of the timing of transactions related to both assets and liabilities; otherwise arises
shortage of cash, funds.
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Monetary Rule- the rule that
the supply of money in circulation should increase annually at a rate equal to the potential
pace
growth of real gross national........
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rule— I.
Explanatory Dictionary of Kuznetsov
Basic Interest Rate Risk Rule— The project is accepted if the interest rate risk is higher than the discount rate, and rejected if the interest rate risk is lower than the discount rate.
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The Six Percent Sixty Day Rule- SIX PERCENT 60-DAY RULE A method that makes it easier in some situations
calculation of interest payments. Using this rule,
interest can be calculated simply by dividing the amount........
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municipal revenue analysts
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analysts for municipal
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Its essence is that
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The 48 Hour Rule- The requirement stated in
Code of Uniform Practice of the Association of Government Securities Dealers
papers, according to which all
bullet info.........
Economic dictionary
500 dollar rule— The Fed's rule under
Rules "Ti" (Regulation T), according to which, if
lack of funds for
account
client to ensure the purchase of shares in
credit........
Economic dictionary
Rule 72- English. 72 rule a way of estimating the number of years required for the amount invested to double in compound interest. For this you need ........
Economic dictionary
Rule of 78s- English. 78 rule the rule for calculating the monthly interest payment. Since the sum of the numbers of the months in a year (from 1 to 12) is 78, then 12/78 of the annual amount is paid in the first month........
Economic dictionary
S-k rule- REGULATION S-KComprehensive collection of the Securities and Exchange Commission (SEC) on the rules for the disclosure of information, characterizing the requirements for data not related to financial ..........
Economic dictionary
Rule S-x— REGULATION S-X The SECURITIES AND EXCHANGE COMMISSION (SEC) is empowered to set accounting and reporting standards for firms under its jurisdiction. P.S-X contains the main ........
Economic dictionary
Rule S-x (us)- - a rule that requires the inclusion of a statement of changes in financial position (statement of movements in funds) in financial statements, and also establishes requirements for some ........
Economic dictionary
