We begin our acquaintance with ecology, perhaps, with one of the most developed and studied sections - autecology. Autecology focuses on the interaction of individuals or groups of individuals with the conditions of their environment. Therefore, the key concept of autecology is the environmental factor, that is, the factor environment, affecting the body.

No environmental measures are possible without studying the optimal effect of a particular factor on a given biological species. Indeed, how can one protect one species or another if one does not know what living conditions it prefers? Even the “protection” of a species such as Homo sapiens requires knowledge of sanitary and hygienic standards, which are nothing more than the optimum of various environmental factors as applied to humans.

The influence of the environment on the body is called an environmental factor. The exact scientific definition is:

ECOLOGICAL FACTOR - any environmental condition to which living things react with adaptive reactions.

An environmental factor is any element of the environment that has a direct or indirect effect on living organisms during at least one of the phases of their development.

By their nature, environmental factors are divided into at least three groups:

abiotic factors - influences inanimate nature;

biotic factors - the influence of living nature.

anthropogenic factors - influences caused by reasonable and unreasonable human activity ("anthropos" - man).

Man modifies living and inanimate nature, and in a certain sense takes on a geochemical role (for example, releasing carbon immured in the form of coal and oil for many millions of years and releasing it into the air as carbon dioxide). Therefore, anthropogenic factors in the scope and globality of their impact are approaching geological forces.

It is not uncommon for environmental factors to be subjected to a more detailed classification, when it is necessary to point out a specific group of factors. For example, there are climatic (climate-related) and edaphic (soil) environmental factors.

As a textbook example of the indirect action of environmental factors, the so-called bird markets, which are huge concentrations of birds, are cited. The high density of birds is explained by a whole chain of cause and effect relationships. Bird droppings enter the water, organic substances in the water are mineralized by bacteria, the increased concentration of mineral substances leads to an increase in the number of algae, and after them, zooplankton. Fish feed on lower crustaceans that are part of zooplankton, and birds that inhabit the bird colony feed on fish. The chain is closed. Bird droppings act as an environmental factor that indirectly increases the size of a bird colony.

How can we compare the effects of factors so different in nature? Despite the huge number of factors, from the very definition of an environmental factor as an element of the environment that influences the body, something in common follows. Namely: the effect of environmental factors is always expressed in changes in the life activity of organisms, and ultimately leads to a change in population size. This allows us to compare the effects of various environmental factors.

Needless to say, the effect of a factor on an individual is determined not by the nature of the factor, but by its dose. In light of the above, and simple life experience, it becomes obvious that it is the dose of the factor that determines the effect. Indeed, what is the “temperature” factor? This is quite an abstraction, but if you say that the temperature is -40 Celsius, there is no time for abstractions, you better wrap yourself up in everything warm! On the other hand, +50 degrees will not seem much better to us.

Thus, the factor affects the body with a certain dose, and among these doses one can distinguish minimum, maximum and optimal doses, as well as those values ​​​​at which the life of an individual ceases (they are called lethal, or lethal).

The effect of different doses on the population as a whole is very clearly described graphically:

The ordinate axis shows the population size depending on the dose of a particular factor (abscissa axis). The optimal dose of the factor and the dose of the factor at which the vital activity of a given organism is inhibited are identified. On the graph this corresponds to 5 zones:

optimum zone

to the right and left of it are the pessimum zones (from the boundary of the optimum zone to max or min)

lethal zones (beyond max and min), in which the population size is 0.

The range of factor values, beyond which the normal functioning of individuals becomes impossible, is called the limits of endurance.

In the next lesson we will look at how organisms differ in relation to various environmental factors. In other words, in the next lesson we will talk about ecological groups of organisms, as well as about the Liebig barrel and how all this is connected with the determination of the maximum permissible concentration.

Glossary

ABIOTIC FACTOR - a condition or set of conditions of the inorganic world; ecological factor of inanimate nature.

ANTHROPOGENIC FACTOR - an environmental factor that owes its origin to human activity.

PLANKTON is a set of organisms that live in the water column and are unable to actively resist being carried by currents, that is, “floating” in the water.

BIRD MARKET - a colonial settlement of birds associated with the aquatic environment (guillemots, gulls).

Which environmental factors, out of all their diversity, does the researcher primarily pay attention to? It is not uncommon for a researcher to be faced with the task of identifying those environmental factors that inhibit the life activity of representatives of a given population and limit growth and development. For example, it is necessary to find out the reasons for the decline in yield or the reasons for the extinction of a natural population.

With all the diversity of environmental factors and the difficulties that arise when trying to assess their joint (complex) impact, it is important that the factors that make up the natural complex have unequal importance. Back in the 19th century, Liebig (1840), studying the influence of various microelements on plant growth, established: plant growth is limited by the element whose concentration is at a minimum. The deficient factor was called limiting. The so-called “Liebig barrel” helps to represent this situation figuratively.

Liebig barrel

Imagine a barrel with wooden slats on the sides of different heights, as shown in the figure. It’s clear that no matter what height the other slats are, you can only pour as much water into the barrel as the length of the shortest slats (in in this case- 4 dies).

All that remains is to “replace” some terms: let the height of the poured water be some biological or ecological function (for example, productivity), and the height of the slats will indicate the degree of deviation of the dose of one or another factor from the optimum.

Currently, Liebig's law of the minimum is interpreted more broadly. A limiting factor can be a factor that is not only in short supply, but also in excess.

An environmental factor plays the role of a LIMITING FACTOR if this factor is below a critical level or exceeds the maximum tolerable level.

The limiting factor determines the distribution area of ​​the species or (under less severe conditions) affects the general level of metabolism. For example, the phosphate content in seawater is a limiting factor that determines the development of plankton and the productivity of communities in general.

The concept of "limiting factor" applies not only to various elements, but also to all environmental factors. Often, competitive relations act as a limiting factor.

Each organism has limits of endurance in relation to various environmental factors. Depending on how wide or narrow these limits are, eurybiont and stenobiont organisms are distinguished. Eurybionts are able to tolerate a wide range of intensities of various environmental factors. Let's say the fox's habitat ranges from forest-tundra to steppes. Stenobionts, on the contrary, tolerate only very narrow fluctuations in the intensity of the environmental factor. For example, almost all plants of tropical rainforests are stenobionts.

It is not uncommon to indicate which factor is meant. Thus, we can talk about eurythermic (tolerating large temperature fluctuations) organisms (many insects) and stenothermic (for tropical forest plants, temperature fluctuations within +5... +8 degrees C can be destructive); eury/stenohaline (tolerating/not tolerating fluctuations in water salinity); evry/stenobate (living in wide/narrow depth limits of a reservoir) and so on.

The emergence of stenobiont species in the process of biological evolution can be considered as a form of specialization in which greater efficiency is achieved at the expense of adaptability.

Interaction of factors. MPC.

When environmental factors act independently, it is enough to use the concept of “limiting factor” to determine the joint impact of a complex of environmental factors on a given organism. However, in real conditions environmental factors can enhance or weaken each other's effects. For example, frost in the Kirov region is more easily tolerated than in St. Petersburg, since the latter has higher humidity.

Taking into account the interaction of environmental factors is an important scientific problem. Three main types of interaction of factors can be distinguished:

additive - the interaction of factors is a simple algebraic sum of the effects of each factor when acting independently;

synergetic - the joint action of factors enhances the effect (that is, the effect when they act together is greater than the simple sum of the effects of each factor when acting independently);

antagonistic - the joint action of factors weakens the effect (that is, the effect of their joint action is less than the simple sum of the effects of each factor).

Why is it so important to know about the interaction of environmental factors? The theoretical justification for the value of maximum permissible concentrations (MAC) of pollutants or maximum permissible levels (MPL) of exposure to polluting agents (for example, noise, radiation) is based on the law of the limiting factor. The maximum permissible concentration is set experimentally at a level at which pathological changes do not yet occur in the body. This has its own difficulties (for example, most often it is necessary to extrapolate data obtained on animals to humans). However, we are not talking about them now.

It is not uncommon to hear environmental authorities happily report that the level of most pollutants in the city’s atmosphere is within the MPC. And at the same time, the state sanitary and epidemiological authorities state increased level respiratory diseases in children. The explanation could be like this. It is no secret that many atmospheric pollutants have a similar effect: they irritate the mucous membranes of the upper respiratory tract, cause respiratory diseases, etc. And the combined action of these pollutants gives an additive (or synergistic) effect.

Therefore, ideally, when developing MPC standards and when assessing the existing environmental situation, the interaction of factors should be taken into account. Unfortunately, this can be very difficult to do in practice: it is difficult to plan such an experiment, it is difficult to assess the interaction, plus tightening the MPC has negative economic effects.

Glossary

MICROELEMENTS - chemical elements needed by organisms in minute quantities, but determining the success of their development. M. in the form of microfertilizers is used to increase plant productivity.

LIMITING FACTOR - a factor that sets the framework (determining) for the course of some process or for the existence of an organism (species, community).

AREAL - the area of ​​distribution of any systematic group of organisms (species, genus, family) or a certain type of community of organisms (for example, the area of ​​lichen pine forests).

METABOLISM - (in relation to the body) the sequential consumption, transformation, use, accumulation and loss of substances and energy in living organisms. Life is possible only thanks to metabolism.

EURYBIONT - an organism living in various environmental conditions

STENOBIONT is an organism that requires strictly defined conditions of existence.

XENOBIOTIC - a chemical substance foreign to the body, naturally not included in the biotic cycle. As a rule, a xenobiotic is of anthropogenic origin.

Ecosystem

URBAN AND INDUSTRIAL ECOSYSTEMS

general characteristics urban ecosystems.

Urban ecosystems are heterotrophic, the proportion of solar energy fixed by urban plants or solar panels located on the roofs of houses is insignificant. The main sources of energy for city enterprises, heating and lighting of city residents' apartments are located outside the city. These are oil, gas, coal deposits, hydro and nuclear power plants.

The city consumes a huge amount of water, only a small part of which is used by humans for direct consumption. The bulk of water is spent on production processes and household needs. Personal water consumption in cities ranges from 150 to 500 liters per day, and taking into account industry, up to 1000 liters per day per citizen. The water used by cities returns to nature in a polluted state - it is saturated with heavy metals, residues of petroleum products, complex organic substances like phenol, etc. It may contain pathogenic microorganisms. The city emits toxic gases and dust into the atmosphere, and concentrates toxic waste in landfills, which enter aquatic ecosystems with spring water flows. Plants as part of urban ecosystems grow in parks, gardens, and lawns; their main purpose is to regulate the gas composition of the atmosphere. They release oxygen, absorb carbon dioxide and cleanse the atmosphere of harmful gases and dust that enter it during the operation of industrial enterprises and transport. Plants also have great aesthetic and decorative value.

Animals in the city are represented not only by species common in natural ecosystems (birds live in the parks: redstart, nightingale, wagtail; mammals: voles, squirrels and representatives of other groups of animals), but also by a special group of urban animals - human companions. It consists of birds (sparrows, starlings, pigeons), rodents (rats and mice), and insects (cockroaches, bedbugs, moths). Many animals associated with humans feed on garbage in garbage dumps (jackdaws, sparrows). These are city nurses. The decomposition of organic waste is accelerated by fly larvae and other animals and microorganisms.

main feature ecosystems of modern cities is that their ecological balance is disturbed. Man has to take on all the processes of regulating the flow of matter and energy. A person must regulate both the city’s consumption of energy and resources - raw materials for industry and food for people, and the amount of toxic waste entering the atmosphere, water and soil as a result of industrial and transport activities. Finally, it determines the size of these ecosystems, which developed countries, A last years and in Russia, they are quickly “spreading” due to country cottage construction. Low-rise development areas reduce the area of ​​forests and agricultural land, their “sprawling” requires the construction of new highways, which reduces the share of ecosystems capable of producing food and carrying out the oxygen cycle.

Industrial pollution.

In urban ecosystems, industrial pollution is the most dangerous for nature.

Chemical pollution of the atmosphere. This factor is one of the most dangerous to human life. Most common pollutants

Sulfur dioxide, nitrogen oxides, carbon monoxide, chlorine, etc. In some cases, toxic compounds can be formed from two or relatively several relatively harmless substances emitted into the atmosphere under the influence of sunlight. Environmentalists count about 2,000 air pollutants.

The main sources of pollution are thermal power plants. Boiler houses, oil refineries and motor vehicles also heavily pollute the atmosphere.

Chemical pollution of water bodies. Enterprises discharge petroleum products, nitrogen compounds, phenol and many other industrial wastes into water bodies. During oil production, water bodies are polluted with saline species; oil and petroleum products also spill during transportation. In Russia, the lakes of the North of Western Siberia suffer most from oil pollution. In recent years, the danger to aquatic ecosystems from municipal wastewater has increased. These effluents contain an increased concentration of detergents, which are difficult for microorganisms to decompose.

As long as the amount of pollutants emitted into the atmosphere or discharged into rivers is small, ecosystems themselves are able to cope with them. With moderate pollution, the water in the river becomes almost clean after 3-10 km from the source of pollution. If there are too many pollutants, ecosystems cannot cope with them and irreversible consequences begin.

Water becomes unfit for drinking and dangerous for humans. Contaminated water is also unsuitable for many industries.

Soil surface contamination with solid waste. City landfills for industrial and household waste occupy large areas. The garbage may contain toxic substances, such as mercury or other heavy metals, chemical compounds that dissolve in rain and snow waters and then end up in water bodies and groundwater. Devices containing radioactive substances can also get into the trash.

The soil surface can be contaminated with ash deposited from the smoke of coal-fired thermal power plants, enterprises producing cement, refractory bricks, etc. To prevent this contamination, special dust collectors are installed on the pipes.

Chemical contamination of groundwater. Groundwater currents transport industrial pollution over long distances, and it is not always possible to determine their source. The cause of pollution may be the leaching of toxic substances by rain and snow water from industrial landfills. Groundwater pollution also occurs during oil production modern methods when, to increase the recovery of oil reservoirs, salt water that rose to the surface along with the oil during its pumping is reinjected into the wells.

Saline water enters aquifers, and the water in wells acquires a bitter taste and is not suitable for drinking.

Noise pollution. The source of noise pollution may be industrial enterprise or transport. Heavy dump trucks and trams produce especially loud noise. Noise affects the human nervous system, and therefore noise protection measures are taken in cities and enterprises.

Railway and tram lines and roads along which freight transport passes need to be moved from the central parts of cities to sparsely populated areas and green spaces created around them that absorb noise well.

Airplanes should not fly over cities.

Noise is measured in decibels. The ticking of a clock is 10 dB, the whisper is 25, the noise from a busy highway is 80, the noise of an airplane during takeoff is 130 dB. Noise pain threshold - 140 dB. In residential areas during the day, noise should not exceed 50-66 dB.

Pollutants also include: contamination of the soil surface by dumps of overburden and ash, biological pollution, thermal pollution, radiation pollution, electromagnetic pollution.

Air pollution. If we take air pollution over the ocean as a unit, then over villages it is 10 times higher, over small towns - 35 times, and over large cities - 150 times. The thickness of the layer of polluted air over the city is 1.5 - 2 km.

The most dangerous pollutants are benzo-a-pyrene, nitrogen dioxide, formaldehyde, and dust. In the European part of Russia and the Urals, on average, per 1 sq. km, over 450 kg of atmospheric pollutants fell.

Compared to 1980, the amount of sulfur dioxide emissions increased 1.5 times; 19 million tons of atmospheric pollutants were released into the atmosphere by road transport.

Wastewater discharge into rivers amounted to 68.2 cubic meters. km with post-consumption 105.8 cubic meters. km. Industrial water consumption is 46%. The share of untreated wastewater has been decreasing since 1989 and amounts to 28%.

Due to the predominance of westerly winds, Russia receives 8-10 times more atmospheric pollutants from its western neighbors than it sends to them.

Acid rain has negatively affected half of the forests in Europe, and the process of forest drying has begun in Russia. In Scandinavia, 20,000 lakes have already died due to acid rain coming from Great Britain and Germany. Architectural monuments are dying under the influence of acid rain.

Harmful substances coming out of a chimney 100 m high are dispersed within a radius of 20 km, and at a height of 250 m - up to 75 km. The champion pipe was built at a copper-nickel plant in Sudbury (Canada) and has a height of more than 400 m.

Chlorofluorocarbons (CFCs) that destroy the ozone layer enter the atmosphere from gases from cooling systems (in the USA - 48%, and in other countries - 20%), from the use of aerosol cans (in the USA - 2%, and several years ago their sale was banned; in other countries - 35%), solvents used in dry cleaning (20%) and in the production of foam plastics, including styroform (25-

The main source of freons that destroy the ozone layer is industrial refrigerators. A typical household refrigerator contains 350 g of freon, while an industrial refrigerator contains tens of kilograms. Refrigeration facilities only in

Moscow annually uses 120 tons of freon. A significant part of it ends up in the atmosphere due to imperfect equipment.

Pollution of freshwater ecosystems. In 1989, 1.8 tons of phenols, 69.7 tons of sulfates, and 116.7 tons of synthetic surfactants were discharged into Lake Ladoga, a drinking water reservoir for St. Petersburg with a population of six million.

Pollutes aquatic ecosystems and river transport. For example, 400 ships sail on Lake Baikal different sizes, they discharge about 8 tons of petroleum products into the water per year.

At most Russian enterprises, toxic production waste is either dumped into water bodies, poisoning them, or accumulated without recycling, often in huge quantities. These accumulations of deadly waste can be called “ecological mines”; when dams break, they can end up in water bodies. An example of such an “ecological mine” is the Cherepovets chemical plant “Ammophos”. Its settling basin covers an area of ​​200 hectares and contains 15 million tons of waste. The dam that encloses the settling basin is raised annually to

4 m. Unfortunately, the “Cherepovets mine” is not the only one.

In developing countries, 9 million people die every year. By the year 2000, more than 1 billion people will not have enough drinking water.

Pollution of marine ecosystems. About 20 billion tons of garbage have been dumped into the World Ocean - from household waste to radioactive waste. Every year for every 1 sq. km water surface another 17 tons of garbage are added.

Every year, more than 10 million tons of oil are poured into the ocean, which forms a film covering 10-15% of its surface; and 5 g of petroleum products is enough to cover 50 square meters with film. m of water surface. This film not only reduces the evaporation and absorption of carbon dioxide, but also causes oxygen starvation and death of eggs and juvenile fish.

Radiation pollution. It is expected that by 2000 the world will have accumulated

1 million cubic meters m of high-level radioactive waste.

Natural radioactive background affects every person, even those who do not come into contact with nuclear power plants or nuclear weapons. We all receive a certain dose of radiation in our lives, 73% of which comes from radiation from natural bodies (for example, granite in monuments, cladding of houses, etc.), 14% from medical procedures (primarily from visiting an X-ray room) and 14% - to cosmic rays. Over a lifetime (70 years), a person can, without much risk, gain radiation of 35 rem (7 rem from natural sources, 3 rem from space sources and X-ray machines). In the area of ​​the Chernobyl nuclear power plant in the most contaminated areas you can get up to 1 rem per hour. The radiation power on the roof during the fire extinguishing period at the nuclear power plant reached 30,000 roentgens per hour, and therefore, without radiation protection (lead spacesuit), a lethal dose of radiation could be received in 1 minute.

The hourly dose of radiation, lethal for 50% of organisms, is 400 rem for humans, 1000-2000 for fish and birds, from 1000 to 150,000 for plants and 100,000 rem for insects. Thus, the most severe pollution is not an obstacle to the mass reproduction of insects. Among plants, trees are the least resistant to radiation and grasses are the most resistant.

Pollution from household waste. The amount of accumulated garbage is constantly growing. Now there is from 150 to 600 kg of it per year for each city resident. The most garbage is produced in the USA (520 kg per year per inhabitant), in Norway, Spain, Sweden, the Netherlands - 200-300 kg, and in Moscow - 300-320 kg.

For paper to decompose in the natural environment, it takes from 2 to 10 years, a tin can - more than 90 years, a cigarette filter - 100 years, a plastic bag - more than 200 years, plastic - 500 years, glass - more than 1000 years.

Ways to reduce harm from chemical pollution

The most common pollution is chemical. There are three main ways to reduce harm from them.

Dilution. Even treated wastewater must be diluted 10 times (and untreated waste water - 100-200 times). Factories build tall chimneys to ensure that emitted gases and dust are dispersed evenly. Dilution is an ineffective way to reduce harm from pollution and is only permissible as a temporary measure.

Cleaning. This is the main way to reduce emissions of harmful substances into the environment in Russia today. However, as a result of cleaning, a lot of concentrated liquid and solid waste is generated, which also has to be stored.

Replacement of old technologies with new ones - low-waste. Due to deeper processing, it is possible to reduce the amount of harmful emissions tens of times. Waste from one production becomes raw material for another.

Ecologists in Germany gave figurative names to these three methods of reducing environmental pollution: “extend the pipe” (dilution by dispersion), “plug the pipe” (cleaning) and “tie the pipe in a knot” (low-waste technologies). The Germans restored the ecosystem of the Rhine, which for many years was a sewer where waste from industrial giants was dumped. This was only done in the 80s, when they finally “tie the pipe in a knot.”

The level of environmental pollution in Russia is still very high, and an environmentally unfavorable situation dangerous to public health has developed in almost 100 cities of the country.

Some improvement in the environmental situation in Russia has been achieved due to improved operation of treatment facilities and a drop in production.

Further reductions in emissions of toxic substances into the environment can be achieved by introducing less hazardous, low-waste technologies. However, in order to “tie the pipe in a knot,” it is necessary to update equipment at enterprises, which requires very large investments and therefore will be carried out gradually.

Cities and industrial facilities (oil fields, quarries for coal and ore, chemical and metallurgical plants) operate using energy that comes from other industrial ecosystems ( energy complex), and their products are not plant and animal biomass, but steel, cast iron and aluminum, various machines and instruments, Construction Materials, plastics and much more that does not exist in nature.

Urban environmental problems are primarily problems of reducing emissions of various pollutants into the environment and protecting water, atmosphere, and soil from cities. They are solved by creating new low-waste technologies and production processes and efficient treatment facilities.

Plants play a major role in mitigating the influence of urban environmental factors on humans. Green spaces improve the microclimate, trap dust and gases, and have a beneficial effect on mental condition townspeople

Literature:

Mirkin B.M., Naumova L.G. Ecology of Russia. Textbook from the Federal set for grades 9 - 11 of secondary schools. Ed. 2nd, revised

And additional - M.: JSC MDS, 1996. - 272 pp.

Environmental factors and the concept of ecological niche

Concept of environmental factor

1.1.1. The concept of environmental factors and their classification

From an environmental perspective Wednesday - these are natural bodies and phenomena with which the organism is in direct or indirect relationships. The environment surrounding an organism is characterized by enormous diversity, consisting of many elements, phenomena, conditions that are dynamic in time and space, which are considered as factors .

Environmental factor - this is any environmental condition, capable of exerting a direct or indirect influence on living organisms, at least during one of the phases of their individual development. In turn, the body reacts to the environmental factor with specific adaptive reactions.

Thus, environmental factors- these are all elements of the natural environment that influence the existence and development of organisms, and to which living beings react with adaptation reactions (beyond the ability of adaptation, death occurs).

It should be noted that in nature, environmental factors act in a complex manner. This is especially important to remember when assessing the impact of chemical pollutants. In this case, the “total” effect, when the negative effect of one substance is superimposed on the negative effect of others, and to this is added the influence stressful situation, noise, various physical fields, significantly changes the MPC values ​​given in reference books. This effect is called synergistic.

The most important concept is limiting factor, that is, one whose level (dose) approaches the limit of the body’s endurance, the concentration of which is lower or higher than optimal. This concept is defined by Liebig's laws of minimum (1840) and Shelford's laws of tolerance (1913). The most often limiting factors are temperature, light, nutrients, currents and pressure in the environment, fires, etc.

The most common organisms are those with a wide range of tolerance to all environmental factors. The highest tolerance is characteristic of bacteria and blue-green algae, which survive in a wide range of temperatures, radiation, salinity, pH, etc.

Ecological studies related to determining the influence of environmental factors on the existence and development of certain types of organisms, the relationship of the organism with the environment, are the subject of science autecology . The branch of ecology that studies the associations of populations of various species of plants, animals, microorganisms (biocenoses), the ways of their formation and interaction with the environment is called synecology . Within the boundaries of synecology there are phytocenology, or geobotany (the object of study is groupings of plants), biocenology (groupings of animals).

Thus, the concept of an environmental factor is one of the most general and extremely broad concepts of ecology. Accordingly, the task of classifying environmental factors has proven to be very difficult, so there is still no generally accepted option. At the same time, agreement has been reached regarding the advisability of using certain characteristics when classifying environmental factors.

Traditionally, three groups of environmental factors have been identified:

1) abiotic (inorganic conditions - chemical and physical, such as the composition of air, water, soil, temperature, light, humidity, radiation, pressure, etc.);

2) biotic (forms of interaction between organisms);

3) anthropogenic (forms of human activity).

Today, there are ten groups of environmental factors (the total number is about sixty), combined into a special classification:

1. by time – factors of time (evolutionary, historical, active), periodicity (periodic and non-periodic), primary and secondary;

2. by origin (cosmic, abiotic, biotic, natural, technogenic, anthropogenic);

3. by environment of occurrence (atmospheric, water, geomorphological, ecosystem);

4. by nature (informational, physical, chemical, energy, biogenic, complex, climatic);

5. by object of influence (individual, group, species, social);

6. by degree of influence (lethal, extreme, limiting, disturbing, mutagenic, teratogenic);

7. according to the conditions of action (density-dependent or independent);

8. according to the spectrum of influence (selective or general action).

First of all, environmental factors are divided into external (exogenous or entopic) And internal (endogenous) in relation to a given ecosystem.

TO external These include factors whose actions, to one degree or another, determine the changes occurring in the ecosystem, but they themselves practically do not experience its reverse influence. These are solar radiation, precipitation intensity, atmospheric pressure, wind speed, current speed, etc.

Unlike them internal factors correlate with the properties of the ecosystem itself (or its individual components) and actually form its composition. These are the numbers and biomass of populations, reserves of various substances, characteristics of the ground layer of air, water or soil mass, etc.

The second common classification principle is the division of factors into biotic And abiotic . The first includes various variables that characterize the properties of living matter, and the second - the non-living components of the ecosystem and its external environment. The division of factors into endogenous - exogenous and biotic - abiotic does not coincide. In particular, there are both exogenous biotic factors, for example, the intensity of the introduction of seeds of a certain species into the ecosystem from outside, and endogenous abiotic factors, such as the concentration of O 2 or CO 2 in the ground layer of air or water.

The classification of factors according to the general nature of their origin or object of influence. For example, among exogenous factors there are meteorological (climatic), geological, hydrological, migration (biogeographic), anthropogenic factors, and among endogenous factors - micrometeorological (bioclimatic), soil (edaphic), water and biotic.

An important classification indicator is nature of dynamics environmental factors, especially the presence or absence of its frequency (daily, lunar, seasonal, perennial). This is due to the fact that the adaptive reactions of organisms to certain environmental factors are determined by the degree of constancy of the influence of these factors, that is, their frequency.

Biologist A.S. Monchadsky (1958) distinguished primary periodic factors, secondary periodic factors and non-periodic factors.

TO primary periodic factors These include mainly phenomena associated with the rotation of the Earth: the change of seasons, daily changes in illumination, tidal phenomena, etc. These factors, which are characterized by regular periodicity, acted even before the appearance of life on Earth, and emerging living organisms had to immediately adapt to them.

Secondary periodic factors - a consequence of primary periodic ones: for example, humidity, temperature, precipitation, the dynamics of plant food, the content of dissolved gases in water, etc.

TO non-periodic These include factors that do not have the correct periodicity or cyclicity. These are soil factors and various types of natural phenomena. Anthropogenic impacts on the environment are often non-periodic factors that can occur suddenly and irregularly. Since the dynamics of natural periodic factors is one of the driving forces of natural selection and evolution, living organisms, as a rule, do not have time to develop adaptive reactions, for example, to a sharp change in the content of certain impurities in the environment.

A special role among environmental factors belongs to summative (additive) factors characterizing the numbers, biomass or population densities of organisms, as well as reserves or concentrations of various forms of matter and energy, the temporal changes of which are subject to conservation laws. Such factors are called resources . For example, they talk about the resources of heat, moisture, organic and mineral food, etc. In contrast, factors such as the intensity and spectral composition of radiation, noise level, redox potential, wind or current speed, size and shape of food, etc., which greatly affect organisms, are not classified as resources, i.e. .To. conservation laws do not apply to them.

The number of possible environmental factors seems potentially unlimited. However, in terms of the degree of impact on organisms, they are far from equivalent, as a result of which in ecosystems different types some factors stand out as the most significant, or imperative . In terrestrial ecosystems, exogenous factors usually include intensity solar radiation, temperature and humidity, intensity of precipitation, wind speed, rate of introduction of spores, seeds and other embryos or influx of adults from other ecosystems, as well as all kinds of anthropogenic impacts. Endogenous imperative factors in terrestrial ecosystems are the following:

1) micrometeorological - illumination, temperature and humidity of the ground layer of air, the content of CO 2 and O 2 in it;

2) soil - temperature, humidity, soil aeration, physical and mechanical properties, chemical composition, humus content, availability of mineral nutrients, redox potential;

3) biotic - population density different types, their age and sex composition, morphological, physiological and behavioral characteristics.

1.1.2. The space of environmental factors and the function of the response of organisms to a set of environmental factors

The intensity of the impact of each environmental factor can be characterized numerically, that is, described by a mathematical variable that takes a value on a certain scale.

Environmental factors can be ordered by their strength relative to their impact on an organism, population, ecosystem, that is ranked . If the value of the first most influential factor is measured by the variable X 1, second - variable X 2 , … , n th - variable x n etc., then the entire complex of environmental factors can be represented by the sequence ( X 1 , X 2 , … , x n, ...).In order to characterize the many possible complexes of environmental factors that obtain at different values ​​of each of them, it is advisable to introduce the concept of a space of environmental factors, or, in other words, ecological space.

The space of environmental factors Let's call the Euclidean space, the coordinates of which are compared to the ranked environmental factors:

To quantitatively characterize the impact of environmental factors on the vital signs of individuals, such as growth rate, development, fertility, life expectancy, mortality, nutrition, metabolism, physical activity, etc. (let them be numbered with an index k= 1, …, m), the concept of f at n To ts And I X O T To l And ka . Values ​​accepted by the indicator with number k on a certain scale with varying environmental factors, as a rule, they are limited from below and from above. Let us denote by a segment on the scale of values ​​of one of the indicators ( k th) vital activity of the ecosystem.

Response function k- indicator on the totality of environmental factors ( X 1 , X 2 , … , x n, ...) is called a function φ k, displaying ecological space E to the scale Ik:

,

which to each point ( X 1 , X 2 , … , x n, …) space E matches the number φ k(X 1 , X 2 , … , x n, …) on the scale Ik .

Although the number of environmental factors is potentially unlimited and, therefore, the dimensions of ecological space are infinite E and the number of response function arguments φ k(X 1 , X 2 , … , x n, ...), in reality it is possible to identify a finite number of factors, for example n, with the help of which it is possible to explain a given part of the total variation of the response function. For example, the first 3 factors can explain 80% of the total variation in the indicator φ , the first 5 factors – 95%, the first 10 – 99%, etc. The rest, not included in the list of factors indicated, do not have a decisive impact on the indicator being studied. Their influence can be considered as some " ecological"noise superimposed on the action of imperative factors.

This allows from infinite-dimensional space E go to it n-dimensional subspace En and consider the narrowing of the response function φ k to this subspace:

and where εn+1 – random " environmental noise".

Any living organism does not need temperature, humidity, mineral and organic substances or any other factors in general, but their specific regime, that is, there are some upper and lower limits on the amplitude of permissible fluctuations of these factors. The wider the limits of any factor, the higher the stability, that is tolerance of this organism.

IN typical cases the response function has the form of a convex curve, monotonically increasing from the minimum value of the factor xj s (lower tolerance limit) to a maximum at the optimal factor value xj 0 and monotonically decreasing to maximum value factor a xj e (upper limit of tolerance).

Interval Xj = [x j s, x j e ] is called tolerance interval for this factor, and point xj 0 at which the response function reaches an extremum is called optimum point on this factor.

The same environmental factors have different effects on organisms of different species living together. For some they may be favorable, for others they may not. An important element is the reaction of organisms to the influence of an environmental factor, the negative effect of which can occur in the event of an excess or deficiency of the dose. Therefore, there is the concept of a favorable dose or optimum zones factor and pessimum zones (range of factor dose values ​​in which organisms feel depressed).

The ranges of the optimum and pessimum zones are the criterion for determining ecological valency – the ability of a living organism to adapt to changes in environmental conditions. It is expressed quantitatively by the range of the environment within which the species normally exists. The ecological valency of different species can be very different (reindeer can withstand air temperature fluctuations from -55 to +25÷30°C, and tropical corals die even when the temperature changes by 5-6°C). According to ecological valency, organisms are divided into stenobionts – with low adaptability to environmental changes (orchids, trout, Far Eastern hazel grouse, deep-sea fish) and eurybionts – with greater adaptability to environmental changes (Colorado beetle, mice, rats, wolves, cockroaches, reeds, wheatgrass). Within the boundaries of eurybionts and stenobionts, depending on a specific factor, organisms are divided into eurythermic and stenothermic (based on their response to temperature), euryhaline and stenohaline (based on their response to the salinity of the aquatic environment), euryphotes and stenophotes (based on their response to lighting).

To express the relative degree of tolerance, there are a number of terms in ecology that use the prefixes steno -, which means narrow, and evry - - wide. Species that have a narrow tolerance range (1) are called stenoeks , and species with a wide range of tolerance (2) – euryecami on this factor. Imperative factors have their own terms:

by temperature: stenothermic - eurythermic;

by water: stenohydric – euryhydric;

according to salinity: stenohaline – euryhaline;

according to food: stenophagous – euryphagous;

according to the choice of habitat: walloic – euryoic.

1.1.3. Law of limiting factor

The presence or prosperity of an organism in a given habitat depends on a complex of environmental factors. For each factor there is a range of tolerance, beyond which the body is not able to exist. The impossibility of flourishing or the absence of an organism is determined by those factors whose values ​​approach or exceed the limits of tolerance.

Limiting We will consider a factor according to which, in order to achieve a given (small) relative change in the response function, a minimum relative change in this factor is required. If

then the limiting factor will be Xl, that is, the limiting factor is along which the gradient of the response function is directed.

It is obvious that the gradient is directed normal to the boundary of the tolerance region. And for the limiting factor, all other things being equal, there is a greater chance of going beyond the area of ​​tolerance. That is, the limiting factor is the factor whose value is closest to the lower limit of the tolerance interval. This concept is known as " law of the minimum "Liebig.

The idea that the endurance of an organism is determined by the weakest link in the chain of its ecological needs was first clearly demonstrated in 1840. organic chemist Yu. Liebig, one of the founders of agrochemistry, who put forward theory of mineral nutrition of plants. He was the first to study the influence of various factors on plant growth, establishing that crop yield is often limited by nutrients that are not required in large quantities, such as carbon dioxide and water, since these substances are usually present in the environment in abundance, but those that are required in minute quantities, for example, zinc, boron or iron, of which there is very little in the soil. Liebig's conclusion that "the growth of a plant depends on the element of nutrition that is present in the minimum quantity" became known as Liebig's "law of the minimum."

70 years later, the American scientist V. Shelford showed that not only a substance present in a minimum can determine the yield or viability of an organism, but an excess of some element can lead to undesirable deviations. For example, an excess of mercury in the human body relative to a certain norm causes severe functional disorders. If there is a lack of water in the soil, the assimilation of mineral nutrition elements by the plant is difficult, but an excess of water leads to similar consequences: suffocation of the roots, the occurrence of anaerobic processes, acidification of the soil, etc. are possible. Excess and lack of pH in the soil also reduces the yield in a given location. According to V. Shelford, factors present in both excess and deficiency are called limiting, and the corresponding rule is called the law of “limiting factor” or “ law of tolerance ".

The law of the limiting factor is taken into account in measures to protect the environment from pollution. Exceeding the norm of harmful impurities in air and water poses a serious threat to human health.

A number of auxiliary principles can be formulated that complement the “law of tolerance”:

1. Organisms may have a wide range of tolerance for one factor and a narrow range for another.

2. Organisms with a wide range of tolerance to all factors are usually the most widespread.

3. If conditions for one environmental factor are not optimal for a species, then the range of tolerance to other environmental factors may narrow.

4. In nature, organisms very often find themselves in conditions that do not correspond to the optimal range of one or another environmental factor determined in the laboratory.

5. The breeding season is usually critical; During this period, many environmental factors often become limiting. Tolerance limits for reproducing individuals, seeds, embryos and seedlings are usually narrower than for non-reproducing adult plants or animals.

The actual limits of tolerance in nature are almost always narrower than the potential range of activity. This is due to the fact that the metabolic costs of physiological regulation at extreme values ​​of factors narrow the range of tolerance. As conditions approach extremes, adaptation becomes increasingly costly, and the body becomes increasingly less protected from other factors, such as diseases and predators.

1.1.4. Some basic abiotic factors

Abiotic factors of the terrestrial environment . The abiotic component of the terrestrial environment represents a set of climatic and soil factors, consisting of many dynamic elements that influence both each other and living beings.

The main abiotic factors of the terrestrial environment are as follows:

1) Radiant energy coming from the Sun (radiation). Propagates in space in the form of electromagnetic waves. Serves as the main source of energy for most processes in ecosystems. On the one hand, the direct effect of light on protoplasm is fatal to the organism, on the other hand, light serves as the primary source of energy, without which life is impossible. Therefore, many morphological and behavioral characteristics of organisms are associated with solving this problem. Light is not only a vital factor, but also a limiting one, both at maximum and minimum levels. About 99% of the total energy of solar radiation consists of rays with a wavelength of 0.17÷4.0 microns, including 48% in the visible part of the spectrum with a wavelength of 0.4÷0.76 microns, 45% in the infrared (wavelength from 0.75 microns to 1 mm) and about 7% for ultraviolet (wavelength less than 0.4 microns). Infrared rays are of primary importance for life, and in the processes of photosynthesis, orange-red and ultraviolet rays play the most important role.

2) Illumination earth's surface associated with radiant energy and determined by duration and intensity luminous flux. Due to the rotation of the Earth, light and dark periods periodically alternate. Illumination plays a vital role for all living things, and organisms are physiologically adapted to the cycle of day and night, to the ratio of dark and light periods of the day. Almost all animals have so-called circadian (circadian) rhythms of activity associated with the cycle of day and night. In relation to light, plants are divided into light-loving and shade-tolerant.

3) Surface temperature globe determined by the temperature regime of the atmosphere and is closely related to solar radiation. It depends both on the latitude of the area (the angle of incidence of solar radiation on the surface) and on the temperature of the incoming air masses. Living organisms can exist only within a narrow temperature range - from -200°C to 100°C. As a rule, the upper limit values ​​of the factor turn out to be more critical than the lower ones. The range of temperature fluctuations in water is usually smaller than on land, and the temperature tolerance range of aquatic organisms is usually narrower than that of corresponding terrestrial animals. Thus, temperature is an important and very often limiting factor. Temperature rhythms, together with light, tidal, and humidity rhythms, largely control seasonal and daily activity plants and animals. Temperature often creates zonation and stratification of habitats.

4) Ambient air humidity , associated with its saturation with water vapor. The lower layers of the atmosphere are richest in moisture (up to a height of 1.5÷2 km), where up to 50% of all moisture is concentrated. The amount of water vapor contained in the air depends on the air temperature. The higher the temperature, the more moisture the air contains. For each temperature there is a certain limit of air saturation with water vapor, which is called maximum . The difference between maximum and given saturation is called moisture deficiency (lack of saturation). Humidity deficiency - the most important environmental parameter, since it characterizes two quantities at once: temperature and humidity. It is known that an increase in moisture deficiency during certain periods of the growing season promotes increased fruiting of plants, and in a number of animals, such as insects, leads to reproduction up to the so-called “outbreaks”. Therefore, many methods for predicting various phenomena in the world of living organisms are based on the analysis of the dynamics of moisture deficiency.

5) Precipitation , closely related to air humidity, are the result of condensation of water vapor. Atmospheric precipitation and air humidity are of decisive importance for the formation of the water regime of the ecosystem and, thus, are among the most important imperative environmental factors, since water supply is the most important condition for the life of any organism, from a microscopic bacterium to a giant sequoia. The amount of precipitation depends mainly on the paths and nature of large movements of air masses, or so-called “weather systems”. The distribution of precipitation over the seasons is an extremely important limiting factor for organisms. Precipitation - one of the links in the water cycle on Earth, and in their loss there is a sharp unevenness, and therefore they distinguish humid (wet) and arid (dry) zones. The maximum precipitation is in tropical forests (up to 2000 mm/year), the minimum in deserts (0.18 mm/year). Zones with precipitation less than 250 mm/year are already considered arid. As a rule, an uneven distribution of precipitation over the seasons is found in the tropics and subtropics, where the wet and dry seasons are often well defined. In the tropics, this seasonal rhythm of humidity regulates the seasonal activity of organisms (especially reproduction) in much the same way that the seasonal rhythm of temperature and light regulates the activity of organisms in the temperate zone. In temperate climates, precipitation is usually more evenly distributed throughout the seasons.

6) Gas atmospheric composition . Its composition is relatively constant and includes predominantly nitrogen and oxygen with an admixture of small amounts of CO 2 and argon. Other gases - in trace quantities. In addition, the upper layers of the atmosphere contain ozone. Typically, atmospheric air contains solid and liquid particles of water, oxides of various substances, dust and smoke. Nitrogen – the most important biogenic element involved in the formation of protein structures of organisms; oxygen , mainly coming from green plants, provides oxidative processes; carbon dioxide (CO 2) is a natural damper of solar and reciprocal terrestrial radiation; ozone plays a screening role in relation to the ultraviolet part of the solar spectrum, which is destructive for all living things. Impurities of tiny particles affect the transparency of the atmosphere and prevent the passage of sunlight to the surface of the Earth. The concentrations of oxygen (21% by volume) and CO 2 (0.03% by volume) in the modern atmosphere are to some extent limiting for many higher plants and animals.

7) Movement of air masses (wind) . The cause of wind is a pressure difference caused by unequal heating of the earth's surface. The wind flow is directed towards lower pressure, that is, where the air is warmer. The force of the Earth's rotation affects the circulation of air masses. In the surface layer of air, their movement affects all meteorological elements of the climate: temperature, humidity, evaporation from the Earth’s surface and plant transpiration. Wind – the most important factor in the transfer and distribution of impurities in atmospheric air. Wind performs an important function of transporting matter and living organisms between ecosystems. In addition, wind has a direct mechanical effect on vegetation and soil, damaging or destroying plants and destroying soil cover. Such wind activity is most typical for open flat areas of land, seas, coasts and mountainous regions.

8) Atmospheric pressure . Pressure cannot be called a direct limiting factor, although some animals undoubtedly react to its changes; however, pressure is directly related to weather and climate, which have a direct limiting effect on organisms.

Abiotic factors of soil cover . Soil factors are clearly endogenous in nature, since the soil is not only a “factor” of the environment surrounding organisms, but also a product of their vital activity. The soil – this is the framework, the foundation on which almost any ecosystem is built.

The soil - the final result of the action of climate and organisms, especially plants, on the parent rock. Thus, the soil consists of the original material - the underlying mineral substrate And organic component, in which organisms and their waste products are mixed with finely ground and modified starting material. The spaces between the particles are filled with gases and water. Texture and soil porosity – the most important characteristics that largely determine the availability of nutrients to plants and soil animals. In the soil, processes of synthesis and biosynthesis take place, and various chemical reactions of the transformation of substances occur, associated with the life of bacteria.

1.1.5. Biotic factors

Under biotic factors understand the totality of influences of the life activity of some organisms on others.

Relationships between animals, plants, microorganisms (they are also called co-actions ) are extremely diverse. They can be divided into straight And indirect, are mediated through changes in their presence of relevant abiotic factors.

The interactions of living organisms are classified in terms of their reactions to each other. In particular, they highlight homotypic reactions between interacting individuals of the same species and heterotypic reactions during co-actions between individuals of different species.

One of the most important biotic factors is food (trophic) factor . The trophic factor is characterized by the quantity, quality and availability of food. Any type of animal or plant has a clear selectivity to the composition of food. There are different types monophagous feeding on only one species, polyphages , feeding on several species, as well as species feeding on a more or less limited range of food, called broad or narrow oligophages .

Relationships between species are naturally necessary. Species cannot be divided into enemies and them victims, since the relationships between species are reciprocal. Disappearance² victims² may lead to extinction ² enemy².

Surely each of us has noticed how plants of the same species develop well in the forest, but do not feel well in open spaces. Or, for example, some mammal species have large populations while others are more limited under seemingly identical conditions. All life on Earth is one way or another subject to its own laws and rules. Ecology studies them. One of the fundamental statements is Liebig's law of minimum

Limiting what is it?

The German chemist and founder of agricultural chemistry, Professor Justus von Liebig, made many discoveries. One of the most famous and recognized is the discovery of the fundamental limiting factor. It was formulated in 1840 and later expanded and generalized by Shelford. The law states that for any living organism, the most significant factor is the one that deviates the most from its optimal value. In other words, the existence of an animal or plant depends on the degree of severity (minimum or maximum) of a particular condition. Individuals encounter a wide variety of limiting factors throughout their lives.

"Liebig Barrel"

The factor limiting the life activity of organisms can be different. The formulated law is still actively used in agriculture. J. Liebig established that plant productivity depends primarily on the mineral substance (nutrient), which is most poorly expressed in the soil. For example, if nitrogen in the soil is only 10% of the required norm, and phosphorus is 20%, then the factor limiting normal development is the lack of the first element. Therefore, nitrogen-containing fertilizers should be initially added to the soil. The meaning of the law was stated as clearly and clearly as possible in the so-called “Liebig barrel” (pictured above). Its essence is that when the vessel is filled, water begins to overflow where the shortest board is, and the length of the rest no longer matters much.

Water

This factor is the most stringent and significant compared to the others. Water is the basis of life, as it plays an important role in the life of an individual cell and the entire organism as a whole. Maintaining its quantity at the proper level is one of the main physiological functions of any plant or animal. Water as a factor limiting life activity is due to the uneven distribution of moisture over the Earth’s surface throughout the year. In the process of evolution, many organisms have adapted to the economical use of moisture, surviving the dry period in a state of hibernation or dormancy. This factor is most strongly expressed in deserts and semi-deserts, where flora and fauna are very sparse and unique.

Light

Light coming in the form of solar radiation provides everything life processes on the planet. Organisms care about its wavelength, duration of exposure, and radiation intensity. Depending on these indicators, the body adapts to environmental conditions. As a factor limiting existence, it is especially pronounced at great sea depths. For example, plants are no longer found at a depth of 200 m. Together with lighting, at least two more limiting factors “work” here: pressure and oxygen concentration. This can be contrasted with the tropical rainforests of South America, as the most favorable territory for life.

Ambient temperature

It's no secret that all physiological processes occurring in the body depend on external and internal temperature. Moreover, most species are adapted to a rather narrow range (15-30 °C). The dependence is especially pronounced in organisms that are not able to independently maintain a constant body temperature, for example, reptiles. In the process of evolution, many adaptations have been formed that allow one to overcome this limited factor. Thus, in hot weather, in order to avoid overheating, it intensifies in plants through stomata, in animals - through skin And respiratory system, as well as behavioral characteristics (hiding in the shadows, burrows, etc.).

Pollutants

The significance cannot be underestimated. The last few centuries for humans have been marked by rapid technical progress and the rapid development of industry. This has led to harmful emissions into water bodies, soil and the atmosphere increasing several times. It is possible to understand which factor limits this or that species only after research. This state of affairs explains the fact that the species diversity of individual regions or areas has changed beyond recognition. Organisms change and adapt, some replace others.

All these are the main factors limiting life. In addition to them, there are many others, which are simply impossible to list. Each species and even individual is individual, therefore the limiting factors will be very diverse. For example, the percentage of oxygen dissolved in water is important for trout; for plants, the quantitative and qualitative composition of pollinating insects, etc.

All living organisms have certain limits of endurance due to one or another limiting factor. Some are quite wide, others are narrow. Depending on this indicator, eurybionts and stenobionts are distinguished. The former are able to tolerate a large amplitude of fluctuations of various limiting factors. For example, living everywhere from the steppes to the forest-tundra, wolves, etc. Stenobionts, on the contrary, are able to withstand very narrow fluctuations, and these include almost all rain forest plants.

ENVIRONMENTAL FACTORS

Environmental factors - these are certain conditions and elements of the environment that have a specific effect on a living organism. The body reacts to environmental factors with adaptive reactions. Environmental factors determine the living conditions of organisms.

Classification of environmental factors (by origin)

• 1. Abiotic factors are a set of inanimate factors that affect the life and distribution of living organisms. Among them are:
• 1.1. Physical factors- such factors, the source of which is a physical condition or phenomenon (for example, temperature, pressure, humidity, air movement, etc.).
• 1.2. Chemical factors- factors that are determined by the chemical composition of the environment (salinity of water, oxygen content in the air, etc.).
• 1.3. Edaphic factors(soil) - a set of chemical, physical, mechanical properties of soils and rocks that affect both the organisms for which they are a habitat and the root system of plants (humidity, soil structure, content of nutrients, etc.).
• 2. Biotic factors - a set of influences of the life activity of some organisms on the life activity of others, as well as on the inanimate component of the environment.
• 2.1. Intraspecific interactions characterize the relationships between organisms at the population level. They are based on intraspecific competition.
• 2.2. Interspecies interactions characterize the relationship between various types, which can be favorable, unfavorable and neutral. Accordingly, we denote the nature of the impact +, - or 0. Then the following types of combinations of interspecies relationships are possible:
• 00 neutralism- both types are independent and have no effect on each other; Rarely found in nature (squirrel and elk, butterfly and mosquito);

+0 commensalism- one species benefits, while the other has no benefit, no harm either; (large mammals (dogs, deer) serve as carriers of fruits and seeds of plants (burdock), receiving neither harm nor benefit);

-0 amensalism- one species experiences inhibition of growth and reproduction from another; (light-loving herbs growing under the spruce suffer from shading, but the tree itself does not care about this);

++ symbiosis- mutually beneficial relationships:

• ? mutualism- species cannot exist without each other; figs and the bees that pollinate them; lichen;
• ? protocooperation- coexistence is beneficial to both species, but is not a prerequisite for survival; pollination of various meadow plants by bees;
• - - competition- each type has an adverse effect on the other; (plants compete with each other for light and moisture, i.e. when they use the same resources, especially if they are insufficient);

Predation - a predatory species feeds on its prey;

There is another classification of environmental factors. Most factors change qualitatively and quantitatively over time. For example, climatic factors (temperature, illumination, etc.) change throughout the day, season, and year. Factors whose changes are repeated regularly over time are called periodic . These include not only climatic, but also some hydrographic ones - ebbs and flows, some ocean currents. Factors that arise unexpectedly (volcanic eruption, predator attack, etc.) are called non-periodic .

The interaction between man and his environment has been the object of study in medicine at all times. To assess the effects of various environmental conditions, the term “ecological factor” was proposed, which is widely used in environmental medicine.

A factor (from the Latin factor - doing, producing) is the cause, the driving force of any process, phenomenon, determining its character or certain features.

An environmental factor is any environmental impact that can have a direct or indirect effect on living organisms. An environmental factor is an environmental condition to which a living organism reacts with adaptive reactions.

Environmental factors determine the living conditions of organisms. The conditions of existence of organisms and populations can be considered as regulating environmental factors.

Not all environmental factors (for example, light, temperature, humidity, the presence of salts, the supply of nutrients, etc.) are equally important for the successful survival of the organism. The relationship of an organism with its environment is a complex process in which the weakest, “vulnerable” links can be identified. Those factors that are critical or limiting for the life of an organism are of greatest interest, primarily from a practical point of view.

The idea that the body's endurance is determined by its weakest link

all his needs, was first expressed by K. Liebig in 1840. He formulated a principle that is known as Liebig’s law of the minimum: “The substance found in the minimum controls the harvest and determines the size and stability of the latter over time.”

The modern formulation of J. Liebig’s law is as follows: “The vital capabilities of an ecosystem are limited by those environmental environmental factors, the quantity and quality of which are close to the minimum required by the ecosystem; their reduction leads to the death of the organism or the destruction of the ecosystem.”

The principle, originally formulated by K. Liebig, is currently extended to any environmental factors, but it is supplemented by two restrictions:

Applies only to systems in a stationary state;

Refers not only to one factor, but also to a complex of factors that are different in nature and interact in their influence on organisms and populations.

According to prevailing ideas, a limiting factor is considered to be one in which a minimum relative change in this factor is required to achieve a given (sufficiently small) relative change in the response.

Along with the influence of a deficiency, a “minimum” of environmental factors, the influence of an excess, that is, a maximum of factors such as heat, light, moisture, can also be negative. The idea of ​​the limiting influence of the maximum, along with the minimum, was introduced by V. Shelford in 1913, who formulated this principle as the “law of tolerance”: The limiting factor in the prosperity of an organism (species) can be both the minimum and the maximum of environmental impact, the range between which determines the amount of endurance ( tolerance) of the body in relation to this factor.

The law of tolerance, formulated by V. Shelford, was supplemented by a number of provisions:

Organisms may have a wide range of tolerance for one factor and a narrow range for another;

Organisms with a large range of tolerance are the most widespread;

The range of tolerance for one environmental factor may depend on other environmental factors;

If conditions for one environmental factor are not optimal for a species, then this also affects the range of tolerance for other environmental factors;

The limits of tolerance depend significantly on the state of the body; Thus, the tolerance limits for organisms during the breeding season or during early stage developmental stage is usually narrower than for adults;

The range between the minimum and maximum of environmental factors is usually called the limits or range of tolerance. To designate the limits of tolerance to environmental conditions, the terms “eurybiont” - an organism with a wide limit of tolerance - and “stenobiont” - with a narrow one - are used.

At the level of communities and even species, the phenomenon of factor compensation is known, which is understood as the ability to adapt (adapt) to environmental conditions in such a way as to weaken the limiting influence of temperature, light, water and other physical factors. Species with a wide geographic distribution almost always form populations adapted to local conditions - ecotypes. In relation to people, there is the term ecological portrait.

It is known that not all natural environmental factors are equally important for human life. Thus, the most significant are considered to be the intensity of solar radiation, air temperature and humidity, the concentration of oxygen and carbon dioxide in the ground layer of air, and the chemical composition of soil and water. The most important environmental factor is food. To maintain life, for growth and development, reproduction and preservation of the human population, energy is needed, which is obtained from the environment in the form of food.

There are several approaches to classifying environmental factors.

In relation to the body, environmental factors are divided into: external (exogenous) and internal (endogenous). It is believed that external factors acting on the body are not themselves subject to, or are almost not subject to, its influence. These include environmental factors.

External environmental factors in relation to the ecosystem and living organisms are impacts. The reaction of an ecosystem, biocenosis, populations and individual organisms to these impacts is called a response. The nature of the response to the influence determines the body’s ability to adapt to environmental conditions, adapt and acquire resistance to the influence of various environmental factors, including adverse effects.

There is also such a thing as a lethal factor (from Latin - letalis - deadly). This is an environmental factor, the action of which leads to the death of living organisms.

When certain concentrations are reached, many chemical and physical pollutants can be lethal.

Internal factors correlate with the properties of the organism itself and form it, i.e. are included in its composition. Internal factors are the number and biomass of populations, the number of different chemical substances, characteristics of water or soil mass, etc.

According to the criterion of “life,” environmental factors are divided into biotic and abiotic.

The latter include non-living components of the ecosystem and its external environment.

Abiotic environmental factors are components and phenomena of inanimate, inorganic nature that directly or indirectly affect living organisms: climatic, soil and hydrographic factors. The main abiotic environmental factors are temperature, light, water, salinity, oxygen, electromagnetic characteristics, soil.

Abiotic factors are divided into:

Physical

Chemical

Biotic factors (from the Greek biotikos - life) are factors of the living environment that affect the life of organisms.

Biotic factors are divided into:

Phytogenic;

Microbiogenic;

Zoogenic:

Anthropogenic (socio-cultural).

The action of biotic factors is expressed in the form of mutual influence of some organisms on the life activity of other organisms and all together on the habitat. There are: direct and indirect relationships between organisms.

IN last decades The term anthropogenic factors is increasingly being used, i.e. caused by man. Anthropogenic factors are contrasted with natural or natural factors.

An anthropogenic factor is a set of environmental factors and impacts caused by human activity in ecosystems and the biosphere as a whole. An anthropogenic factor is the direct impact of humans on organisms or the impact on organisms through human changes in their habitat.

Environmental factors are also divided into:

1. Physical

Natural

Anthropogenic

2. Chemical

Natural

Anthropogenic

3. Biological

Natural

Anthropogenic

4. Social (socio-psychological)

5. Informational.

Ecological factors are also divided into climatic-geographical, biogeographical, biological, as well as soil, water, atmospheric, etc.

Physical factors.

Physical natural factors include:

Climatic, including local microclimate;

Geomagnetic activity;

Natural background radiation;

Cosmic radiation;

Terrain;

Physical factors are divided into:

Mechanical;

Vibration;

Acoustic;

EM radiation.

Physical anthropogenic factors:

Microclimate of settlements and premises;

Pollution of the environment by electromagnetic radiation (ionizing and non-ionizing);

Noise pollution;

Thermal pollution of the environment;

Deformation of the visible environment (changes in the terrain and color scheme in populated areas).

Chemical factors.

Natural chemical factors include:

Chemical composition lithosphere:

Chemical composition of the hydrosphere;

Chemical composition of the atmosphere,

Chemical composition of food.

The chemical composition of the lithosphere, atmosphere and hydrosphere depends on the natural composition + release of chemicals as a result of geological processes (for example, hydrogen sulfide impurities as a result of the eruption of a volcano) and the vital activity of living organisms (for example, impurities in the air of phytoncides, terpenes).

Anthropogenic chemical factors:

Household waste,

Industrial waste,

Synthetic materials used in everyday life, agriculture and industrial production,

Pharmaceutical industry products,

Food additives.

The effect of chemical factors on the human body can be due to:

Excess or deficiency of natural chemical elements V

environment (natural microelementoses);

Excessive content of natural chemical elements in the environment

environment associated with human activities (anthropogenic pollution),

The presence in the environment of chemical elements unusual for it

(xenobiotics) due to anthropogenic pollution.

Biological factors

Biological, or biotic (from the Greek biotikos - life) environmental factors are factors of the living environment that affect the life activity of organisms. The action of biotic factors is expressed in the form of mutual influence of some organisms on the life activity of others, as well as their joint influence on the habitat.

Biological factors:

Bacteria;

Plants;

Protozoa;

Insects;

Invertebrates (including helminths);

Vertebrates.

Social environment

Human health is not completely determined by the biological and psychological properties acquired during ontogenesis. Man is a social being. He lives in a society governed by state laws, on the one hand, and on the other, by so-called generally accepted laws, moral guidelines, rules of behavior, including those involving various restrictions, etc.

Society becomes more and more complex every year and has an increasing impact on the health of the individual, population, and society. In order to enjoy the benefits of a civilized society, a person must live in strict dependence on the lifestyle accepted in society. For these benefits, often very dubious, the individual pays with part of his freedom, or completely with all his freedom. But a person who is not free and dependent cannot be completely healthy and happy. Some part of human freedom, given to a techno-critical society in exchange for the advantages of civilized life, constantly keeps him in a state of neuropsychic tension. Constant neuropsychic stress and overstrain leads to a decrease in mental stability due to a decrease in reserve capabilities nervous system. In addition, there are many social factors that can lead to a breakdown in a person’s adaptive capabilities and the development of various diseases. These include social disorder, uncertainty about the future, and moral oppression, which are regarded as leading risk factors.

Social factors

Social factors are divided into:

1. social system;

2. production sector (industry, Agriculture);

3. household sphere;

4. education and culture;

5. population;

6. Zoo and medicine;

7. other spheres.

There is also the following grouping of social factors:

1. Social policy that shapes the sociotype;

2. Social security, which has a direct impact on the formation of health;

3. Environmental policy that shapes the ecotype.

Sociotype is an indirect characteristic of the integral social load based on the totality of factors in the social environment.

Sociotype includes:

2. working, rest and living conditions.

Any environmental factor in relation to a person can be: a) favorable - contributing to his health, development and realization; b) unfavorable, leading to his illness and degradation, c) exerting influence of both kinds. It is also equally obvious that in reality most influences belong to the latter type, having both positive and negative sides.

In ecology there is a law of optimum, according to which any environmental

the factor has certain limits of positive influence on living organisms. The optimal factor is the intensity of the environmental factor that is most favorable for the body.

Impacts may also vary in scale: some affect the entire population of the country as a whole, others - residents of a particular region, others - groups identified by demographic characteristics, and others - an individual citizen.

The interaction of factors is the simultaneous or sequential total impact on organisms of various natural and anthropogenic factors, leading to a weakening, strengthening or modification of the action of a separate factor.

Synergism is the combined effect of two or more factors, characterized by the fact that their combined biological effect significantly exceeds the effect of each component and their sum.

It should be understood and remembered that the main harm to health is caused not by individual environmental factors, but by the total integrated environmental load on the body. It consists of an environmental load and a social load.

Environmental load is a set of factors and conditions of the natural and man-made environment unfavorable to human health. Ecotype is an indirect characteristic of the integral environmental load based on a combination of natural and man-made environmental factors.

Ecotype assessments require hygienic data on:

Quality of housing,

Drinking water,

Air,

Soils, food,

Medicines, etc.

Social burden is a set of factors and conditions of social life unfavorable to human health.

Environmental factors shaping public health

1. Climatic and geographical characteristics.

2. Socio-economic characteristics of the place of residence (city, village).

3. Sanitary and hygienic characteristics of the environment (air, water, soil).

4. Peculiarities of nutrition of the population.

5. Characteristics of work activity:

Profession,

Sanitary and hygienic working conditions,

The presence of occupational hazards,

Psychological microclimate in the service,

6. Family and household factors:

Family composition,

The nature of the housing

Average income per family member,

Organization of family life.

Distribution of non-working time,

Psychological climate in the family.

Indicators characterizing the attitude towards the state of health and determining the activity to maintain it:

1. Subjective assessment own health (healthy, sick).

2. Determining the place of personal health and the health of family members in the system of individual values ​​(hierarchy of values).

3. Awareness of factors contributing to the preservation and strengthening of health.

4. The presence of bad habits and addictions.