Not saturating the stomach with food,

The twentieth century chews itself

And he cuts, cuts the tree of life,

Like a ruthless lumberjack...

Great mind! Forbid you

Chop at least the last bough.

Many types of human activity can be considered special environmental factors, which are called anthropogenic; the scale of the action of anthropogenic factors becomes capable of with the action of geological forces; the biosphere reacts to the impact of anthropogenic factors by reducing the number of species, impoverishing the gene pool of populations, changing the direction of natural selection, and extinction of species.

The planet as a whole, the biosphere and society are ecologically indivisible, therefore environmental problems act as universal. However, in each region they manifest themselves and are resolved in their own way, depending on the type of ecosystems, specific physical, geographical and socio-economic conditions. On the other hand, local environmental situations, although important, can only be successfully resolved taking into account a global approach. .

1. At the end of the Cenozoic era, important climate changes occurred in a number of areas of the planet - cooling and drying began. This led to the fact that forests were replaced by open spaces. Living organisms that previously lived in forest thickets and switched to life in open spaces acquired new properties and signs under the influence of environmental factors: construction activity developed (voles, gerbils); a nomadic way of life, migrations arose, the size of the herd increased (in the herd of forest animals there are only 20-30 heads of elk, and the inhabitants of open spaces gather in herds of thousands of deer). The nocturnal lifestyle was replaced by a daytime lifestyle, hierarchical relations in the herd became more complicated, watchdog functions began to be performed alternately by each of its members. It is believed that the ancestors of man - forest animals - in the new conditions fell into difficult circumstances. The main ones were: the disappearance of many tropical forest plants that served as food, the impossibility of predation due to the lack of fangs and claws as a means of attack and defense; slow movement speed compared to most tetrapods of the same size; low birth rate, duration of development of cubs.

This led to the development in human ancestors, as they mastered the terrestrial way of life, signs of the human race - bipedal locomotion, complication of tool activity, improvement of the structure of the hand, and complication of nervous activity. In terms of geology, this happened very recently.

Success in the struggle for existence could only be ensured by a significant superiority of mental abilities compared to all animals that attacked pre-humans or could be their prey. Natural selection favored the development of the human brain.

In the earliest immediate predecessors or even representatives of the most ancient people - Australopithecus, the faces were already relatively flat, the superciliary arches protruded forward, and a powerful lower jaw occupied a significant part of the face. They lived in open spaces and had a complex hierarchy. It was among Australopithecus that tool activity originated as a form of biological adaptation and as a new stage in evolution. Scientists believe that the first stone tool was made about three million years ago. Figure 30 shows flint tools processed using various technologies.

At this stage, the herd of prehumans began to acquire the features of human society, and the prehumans began to acquire the features of people. Various means of communication were born, daily activity developed, man began to use fire.

The use of fire is the first anthropogenic factor, the first bonfire led to the first adverse consequences for the living.

The Neanderthal man had already built a dwelling - huts for 10-12 people, learned to live in any climate.

The development of agriculture (Figure 31) and the domestication of animals (Figure 32) were accompanied by deforestation, grazing and forage, which led to a change in ecosystems.

8.5 thousand years ago, the first smelting of metal was made (Chatal-Hyuyuk, South Turkey). Crafts began to develop, and then industry.

A new stage in the interaction between society and nature was the emergence of cities, the growth of human technical equipment, the development of crafts, arts, and book printing.

A person has acquired the ability to master the world universally, to transform nature (demonstration of a table - a scroll (Fig. 33), characterizing in reverse form the stages of human impact on nature).

2. Human activity has acquired a global character and has become a special superpowerful ecological factor in the existence of living things in the biosphere.

Man is reducing the territories occupied by natural ecosystems. 9-12% of the land surface is plowed, 22-25% are fully or partially cultivated pastures. 458 equators - this is the length of roads on the planet; 24 km for every 100 km 2 - such is the density of roads. In industrialized countries alone, according to the UN, more than three thousand km 2 of landscape disappears under the concrete of highways, settlements, and airports under construction every year.

A person consumes sushi products, reducing the share of natural consumers.

The biomass of mankind and domestic animals is 15–20% of the biomass of terrestrial animals (as of 1980). However, humans and domestic animals consume 1/4 of sushi vegetable production.

Man depletes the reserves of energy accumulated in the "dead ends" of the biosphere.

Modern humanity consumes the potential energy of the biosphere 10 times faster than its accumulation by the activities of organisms that bind solar energy on Earth.

Man uses the resources of the Earth and pollutes the biosphere: he extracts about 100 billion tons of ore, fossil fuels and other raw materials, which is 25 tons per inhabitant of the planet. 96-98% of the extracted raw materials go to waste. There is 1 ton of garbage (food and household) per inhabitant of large cities. 6 billion tons per year of solid waste released into the oceans. Every year, 69-90 million tons of oil and oil products enter the biosphere, and 20 billion tons of carbon dioxide enter the atmosphere. As a result of fuel combustion, the concentration of lead in the air and soil increases, sulfur and nitrogen oxides enter the atmosphere, forming acid rain with water.

The physical pollution of the biosphere is increasing - noise, heat, light, radioactive. The dust content of the air environment is growing.

3. The impact of the anthropogenic factor causes the reactions of biological systems.

a) Death of individuals and population decline.

Moose, deer, roe deer and wild boars, birds and insects perish on the roads under the wheels of vehicles. Field work leads to the death of black grouse, hares, quails to a greater extent than hunting.

Millions of migratory birds are burned in gas flares, where off-gases from oil production are burned. Animals die in oil spills, on wires and poles of power lines (steppe eagles, gravediggers, golden eagles, short-toed eagles, etc.), by swallowing plastic objects floating in the sea (sea turtles), in fishing nets (dolphins, seals).

b) Violations of the ontogeny of organisms.

Pollutants (sulfur dioxide, fluorine and hydrogen fluoride, chlorides and nitrogen dioxide) are the most dangerous for plants, causing burns, and at high concentrations, death of plants and individual individuals. Sulfuric acid and sulfuric acid formed from sulfur dioxide, together with other substances, getting into the soil, reduce its fertility. The acidity of the soil changes, which causes the suppression of the vital activity of bacteria and a decrease in the number of earthworms. The most dangerous pollutant is oil.

Pollutants affect embryos, developing embryos, poisoning them, causing deformity and abnormalities in the development of the body, disruption of the functions of the sex glands and organs, and disruption of the functions of the nervous system.

Do different pollutants, acting simultaneously, have a cumulative effect? the effect of copper on plants is enhanced in the presence of lead salts; copper enhances the effect of radiation, on the contrary, salts of barium, manganese and magnesium weaken this effect.

Under the influence of pollutants, life spans are reduced - especially long-lived species that can accumulate dangerous concentrations of pollutants in the body.

c) Violation of population phenomena.

The structure of the population is changing - the ratio of males and females, individuals of different generations; the number is reduced to such limits that the search for marriage partners is disrupted. Due to pollution of the environment, reproduction cycles are disrupted (asynchrony in the development of germ cells in males and females), the number of pregnant females decreases, the number of cubs in the litter, and the mortality rate of newborns increases. The range of the species is disintegrating, habitat areas are shrinking, and small habitat islands are being isolated.

d) Change in the ecosystem.

Reducing the number of species reduces the complexity of an ecosystem; loss of some species can lead to an outbreak of others; dominant species may be suppressed and replaced by newly invading species; interspecific relationships are destroyed: predator-prey, pollinator-pollinated plant, symbiotic relationships. The death of one plant species can lead to the death of 5¸7 to 30¸35 animal species associated with it, mainly invertebrates. Light, sound, chemical pollution disrupts the existing signaling systems in the natural community between species. As a result of a change in the structure of the community, its stability is disturbed, and mass outbreaks of numbers occur - as a rule, invertebrates. Thus, we are witnessing a gigantic impoverishment of the gene pool of the biosphere due to the extinction of species, a reduction in their population diversity and the number of individuals in all populations that are declining across the territory. Every day, one species of animals disappears irretrievably from this number, and one species of plants disappears every week. Today, there are only 25 birds for every inhabitant of the planet, and by the year 2000 this ratio will decrease even more.

Natural resources essential for human survival and sustainable development are increasingly being destroyed or depleted. At the same time, the need for these resources is growing rapidly. If current rates of soil degradation continue, a third of the world's arable land will be lost in the next 20 years. Similarly, by the end of this century (at current rates of deforestation), the remaining area of ​​uncut tropical forests will be halved. It is expected that during this period the population of the Earth will increase by one and a half times - from a little over 5 billion to almost 6 billion people.

It became obvious that the balance of biospheric processes, disturbed by human economic activity, is being restored more slowly than ever before. The adaptive mechanisms of the biosphere are working "at the limit". The gene pool of the biosphere is depleted, creating a threat of unpredictable evolutionary consequences.

4. Many scientists characterize the current ecological situation as an “environmental crisis”, “crisis of the natural environment”.

Environmental problems are classified as global and affect both the world as a whole and its individual regions and countries.

The solution of environmental problems - in particular, the conservation of the gene pool of the biosphere - is becoming increasingly urgent.

Mankind and each person, each of us must realize the crisis situation and put forward ideas to save life on the planet.

The history of ecological knowledge goes back many centuries. Already primitive people needed to have certain knowledge about plants and animals, their way of life, relationships with each other and with the environment. As part of the general development of the natural sciences, there was also an accumulation of knowledge that now belongs to the field of environmental science. As an independent isolated discipline, ecology stood out in the 19th century.

The term Ecology (from the Greek eco - house, logos - teaching) was introduced into science by the German biologist Ernest Haeckel.

In 1866, in his work “The General Morphology of Organisms”, he wrote that this is “... the sum of knowledge related to the economics of nature: the study of the totality of the relationship of an animal with its environment, both organic and inorganic, and above all its friendly or hostile relations with those animals and plants with which it directly or indirectly comes into contact. This definition refers ecology to the biological sciences. At the beginning of the XX century. the formation of a systematic approach and the development of the doctrine of the biosphere, which is a vast field of knowledge, which includes many scientific areas of both the natural and humanitarian cycles, including general ecology, led to the spread of ecosystem views in ecology. Ecosystem has become the main object of study in ecology.

An ecosystem is a set of living organisms that interact with each other and with their environment through the exchange of matter, energy and information in such a way that this single system remains stable for a long time.

The ever-increasing impact of man on the environment has required a new expansion of the boundaries of ecological knowledge. In the second half of the XX century. scientific and technological progress has led to a number of problems that have received the status of global ones, thus, in the field of view of ecology, the issues of a comparative analysis of natural and man-made systems and the search for ways for their harmonious coexistence and development have clearly emerged.

Accordingly, the structure of ecological science was differentiated and complicated. Now it can be represented as four main branches, which are further divided: Bioecology, geoecology, human ecology, applied ecology.

Thus, we can define ecology as a science about the general laws of the functioning of ecosystems of various orders, a set of scientific and practical issues of the relationship between man and nature.

2. Environmental factors, their classification, types of impact on organisms

Any organism in nature experiences the influence of a wide variety of components of the external environment. Any properties or components of the environment that affect organisms are called environmental factors.

Classification of environmental factors. Environmental factors (environmental factors) are diverse, have a different nature and specificity of action. The following groups of environmental factors are distinguished:

1. Abiotic (factors of inanimate nature):

a) climatic - lighting conditions, temperature conditions, etc.;

b) edaphic (local) - water supply, soil type, terrain;

c) orographic - air (wind) and water currents.

2. Biotic factors are all forms of influence of living organisms on each other:

Plants Plants. Plants Animals. Plants Mushrooms. Plants Microorganisms. Animals Animals. Animals Mushrooms. Animals Microorganisms. Mushrooms Mushrooms. Mushrooms Microorganisms. Microorganisms Microorganisms.

3. Anthropogenic factors are all forms of activity of human society that lead to a change in the habitat of other species or directly affect their lives. The impact of this group of environmental factors is rapidly increasing from year to year.

Types of impact of environmental factors on organisms. Environmental factors affect living organisms in various ways. They may be:

Irritants that contribute to the appearance of adaptive (adaptive) physiological and biochemical changes (hibernation, photoperiodism);

Limiters that change the geographical distribution of organisms due to the impossibility of existence in these conditions;

Modifiers that cause morphological and anatomical changes in organisms;

Signals indicating changes in other environmental factors.

General patterns of environmental factors:

Due to the extreme diversity of environmental factors, different types of organisms, experiencing their influence, respond to it in different ways, however, it is possible to identify a number of general laws (patterns) of the action of environmental factors. Let's dwell on some of them.

1. The law of optimum

2. Law of ecological individuality of species

3. The law of the limiting (limiting) factor

4. Law of ambiguous action

3. Patterns of the action of environmental factors on organisms

1) The rule of optimum. For an ecosystem, an organism or a certain stage of it

development, there is a range of the most favorable value of the factor. Where

favorable factors population density is maximum. 2) Tolerance.

These characteristics depend on the environment in which the organisms live. If she

stable in its

its-am, it has more chances for the survival of organisms.

3) The rule of interaction of factors. Some factors may increase or

mitigate the effect of other factors.

4) The rule of limiting factors. A factor that is deficient or

excess negatively affects organisms and limits the possibility of manifestation. strength

the action of other factors. 5) Photoperiodism. Under photoperiodism

understand the reaction of the body to the length of the day. response to changing light.

6) Adaptation to the rhythm of natural phenomena. Adaptation to the daily and

seasonal rhythms, tidal phenomena, rhythms of solar activity,

lunar phases and other phenomena that repeat with strict periodicity.

Ek. valency (plasticity) - the ability of org. adapt to the environmental factors. environment.

Patterns of the action of environmental factors on living organisms.

Ecological factors and their classification. All organisms are potentially capable of unlimited reproduction and dispersal: even species that lead an attached lifestyle have at least one developmental phase in which they are capable of active or passive distribution. But at the same time, the species composition of organisms living in different climatic zones does not mix: each of them has a certain set of animal, plant, and fungal species. This is due to the limitation of excessive reproduction and settlement of organisms by certain geographical barriers (seas, mountain ranges, deserts, etc.), climatic factors (temperature, humidity, etc.), as well as relationships between individual species.

Depending on the nature and characteristics of the action, environmental factors are divided into abiotic, biotic and anthropogenic (anthropic).

Abiotic factors are components and properties of inanimate nature that directly or indirectly affect individual organisms and their groups (temperature, light, humidity, gas composition of air, pressure, salt composition of water, etc.).

A separate group of environmental factors includes various forms of human economic activity that change the state of the habitat of various types of living beings, including man himself (anthropogenic factors). In a relatively short period of human existence as a biological species, its activities have radically changed the face of our planet, and every year this influence on nature increases. The intensity of some environmental factors may remain relatively stable over long historical periods of biosphere development (for example, solar radiation, gravity, salt composition of sea water, gas composition of the atmosphere, etc.). Most of them have a variable intensity (temperature, humidity, etc.). The degree of variability of each of the environmental factors depends on the characteristics of the habitat of organisms. For example, the temperature on the soil surface can vary significantly depending on the time of year or day, weather, etc., while in water bodies at depths of more than a few meters there are almost no temperature drops.

Changes in environmental factors can be:

Periodic, depending on the time of day, season, the position of the Moon relative to the Earth, etc.;

Non-periodic, for example, volcanic eruptions, earthquakes, hurricanes, etc.;

Directed over significant historical periods of time, for example, changes in the Earth's climate associated with the redistribution of the ratio of land areas and the oceans.

Each of the living organisms constantly adapts to the whole complex of environmental factors, that is, to the environment, regulating the processes of life in accordance with changes in these factors. Habitat is a set of conditions in which certain individuals, populations, groupings of organisms live.

Patterns of the influence of environmental factors on living organisms. Despite the fact that environmental factors are very diverse and different in nature, some patterns of their influence on living organisms, as well as the reactions of organisms to the action of these factors, are noted. Adaptations of organisms to environmental conditions are called adaptations. They are produced at all levels of the organization of living matter: from molecular to biogeocenotic. Adaptations are not permanent, since they change in the process of the historical development of individual species, depending on changes in the intensity of the action of environmental factors. Each species of organisms is adapted to certain conditions of existence in a special way: there are no two close species that are similar in their adaptations (the rule of ecological individuality). So, the mole (series Insectivores) and the mole rat (series Rodents) are adapted to existence in the soil. But the mole digs passages with the help of its forelimbs, and the mole rat uses its incisors, throwing the soil out with its head.

Good adaptation of organisms to a certain factor does not mean the same adaptation to others (the rule of relative independence of adaptation). For example, lichens, which can settle on substrates poor in organic matter (such as rocks) and withstand dry periods, are very sensitive to air pollution.

There is also the law of optimum: each factor has a positive effect on the body only within certain limits. Favorable for organisms of a certain type, the intensity of the impact of an environmental factor is called the optimum zone. The more the intensity of the action of a certain environmental factor deviates from the optimal one in one direction or another, the more pronounced its depressing effect on organisms (pessimum zone). The value of the intensity of the impact of the environmental factor, according to which the existence of organisms becomes impossible, is called the upper and lower limits of endurance (critical points of maximum and minimum). The distance between the limits of endurance determines the ecological valency of a certain species with respect to one or another factor. Therefore, ecological valence is the range of intensity of the influence of an ecological factor in which the existence of a certain species is possible.

The broad ecological valency of individuals of a certain species with respect to a specific ecological factor is denoted by the prefix "evry-". Thus, arctic foxes are eurythermic animals, since they can withstand significant temperature fluctuations (within 80°C). Some invertebrates (sponges, kilchakiv, echinoderms) are eurybatic organisms, therefore they settle from the coastal zone to great depths, withstanding significant pressure fluctuations. Species that can live in a wide range of fluctuations of various environmental factors are called eurybiontyms. Narrow ecological valency, that is, the inability to withstand significant changes in a certain environmental factor, is denoted by the prefix "steno-" (for example, stenothermic, stenobatni, stenobiontic, etc.).

The optimum and limits of the organism's endurance with respect to a certain factor depend on the intensity of the action of others. For example, in dry, calm weather, it is easier to withstand low temperatures. So, the optimum and limits of endurance of organisms in relation to any environmental factor can shift in a certain direction, depending on the strength and combination of other factors (the phenomenon of interaction of environmental factors).

But the mutual compensation of vital ecological factors has certain limits and none can be replaced by others: if the intensity of the action of at least one factor goes beyond the limits of endurance, the existence of the species becomes impossible, despite the optimal intensity of the action of others. Thus, the lack of moisture inhibits the process of photosynthesis even with optimal illumination and CO2 concentration in the atmosphere.

The factor, the intensity of which goes beyond the limits of endurance, is called restrictive. Limiting factors determine the area of ​​distribution of the species (range). For example, the spread of many species of animals to the north is hampered by a lack of heat and light, to the south by a lack of moisture.

Thus, the presence and prosperity of a certain species in a given habitat is due to its interaction with a whole range of environmental factors. Insufficient or excessive intensity of the action of any of them is impossible for the prosperity and the very existence of individual species.

Environmental factors are any components of the environment that affect living organisms and their groups; they are divided into abiotic (components of inanimate nature), biotic (various forms of interaction between organisms) and anthropogenic (various forms of human economic activity).

Adaptations of organisms to environmental conditions are called adaptations.

Any environmental factor has only certain limits of positive influence on organisms (the law of optimum). The limits of the intensity of the action of the factor, according to which the existence of organisms becomes impossible, are called the upper and lower limits of endurance.

The optimum and limits of endurance of organisms in relation to any environmental factor may vary in a certain direction, depending on the intensity and combination of other environmental factors (the phenomenon of interaction of environmental factors). But their mutual compensation is limited: no vital factor can be replaced by others. An environmental factor that goes beyond the limits of endurance is called a restrictive one; it determines the range of a certain species.

ecological plasticity of organisms

Ecological plasticity of organisms (ecological valence) - the degree of adaptability of a species to changes in the environmental factor. It is expressed by the range of values ​​of environmental factors within which a given species retains normal vital activity. The wider the range, the greater the ecological plasticity.

Species that can exist with small deviations of the factor from the optimum are called highly specialized, and species that can withstand significant changes in the factor are called widely adapted.

Ecological plasticity can be considered both in relation to a single factor and in relation to a complex of environmental factors. The ability of species to tolerate significant changes in certain factors is denoted by the corresponding term with the prefix "evry":

Eurythermal (plastic to temperature)

Eurygoline (water salinity)

Eurythotic (plastic to light)

Eurygyric (plastic to humidity)

Euryoic (plastic to the habitat)

Euryphagic (plastic to food).

Species adapted to small changes in this factor are designated by the term with the prefix "wall". These prefixes are used to express the relative degree of tolerance (for example, in a stenothermic species, the ecological temperature optimum and pessimum are close).

Species with wide ecological plasticity in relation to a complex of ecological factors are eurybionts; species with low individual adaptability - stenobionts. Eurybiontness and istenobiontness characterize various types of adaptation of organisms for survival. If eurybionts develop for a long time in good conditions, then they can lose their ecological plasticity and develop stenobiont traits. Species that exist with significant fluctuations in the factor acquire increased ecological plasticity and become eurybionts.

For example, there are more stenobionts in the aquatic environment, since it is relatively stable in its properties and the amplitudes of fluctuations of individual factors are small. In a more dynamic air-land environment, eurybionts predominate. Warm-blooded animals have a wider ecological valence than cold-blooded animals. Young and old organisms tend to require more uniform environmental conditions.

Eurybionts are widespread, and stenobiont narrows the ranges; however, in some cases, due to their high specialization, stenobionts own vast territories. For example, the fish-eating osprey is a typical stenophage, but in relation to other environmental factors, it is a eurybiont. In search of the necessary food, the bird is able to cover long distances in flight, therefore it occupies a significant area.

Plasticity - the ability of an organism to exist in a certain range of values ​​of the environmental factor. Plasticity is determined by the reaction rate.

According to the degree of plasticity in relation to individual factors, all types are divided into three groups:

Stenotopes are species that can exist in a narrow range of environmental factor values. For example, most plants of moist equatorial forests.

Eurytopes are wide-plastic species capable of developing various habitats, for example, all cosmopolitan species.

Mesotopes occupy an intermediate position between stenotopes and eurytopes.

It should be remembered that a species can be, for example, a stenotope according to one factor and a eurytope according to another, and vice versa. For example, a person is a eurytope in relation to air temperature, but a stenotope in terms of the oxygen content in it.

A person in the environment, on the one hand, is an object of interaction of environmental factors, on the other hand, he himself has an impact on the environment. From this point of view, man and humanity as a whole are characterized by important features. An important feature of a person as an environmental factor is awareness, purposefulness and massive impact on nature.[ ...]

Any biological species has limited energy resources, which limits its impact on the environment. For example, green plants use the energy of the Sun, consumers - part of the energy of organic substances formed by organisms of the previous trophic level. Mankind in the process of labor and intellectual activity expands the range of available energy sources up to the use of nuclear and thermonuclear reactions. This allowed people to overcome the natural growth limits of their numbers.[ ...]

The growth of population, energy supply, technical equipment of people creates the prerequisites for the settlement of any ecological niches. Mankind is the only species on Earth with worldwide distribution. This turns a person into an ecological factor with a global impact.[ ...]

Due to the impact on all the main components of the biosphere, the impact of mankind reaches the most remote ecological zones of the planet, an example is the detection of DDT in the liver of penguins and seals caught in Antarctica, where insecticides have never been used.[ ...]

As a result of labor activity, a person creates an artificial habitat around him. Natural ecosystems are being replaced by anthropogenic ecosystems, in which man is the absolutely dominant factor.[ ...]

As a result of human activity, changes in the physical environment occur - the gas composition of the air, the quality of water and food, the climate, the flow of solar energy and other factors that affect the health and performance of people. In deviating extreme conditions, a lot of effort and money is expended on the artificial creation and maintenance of optimal environmental conditions.[ ...]

The scale of the interaction of modern society with nature is determined not by the biological needs of man, but by the continuously increasing level of technical and social development. The technical power of man has reached scales commensurate with biospheric processes. For example, construction and mining machinery transport more material to the Earth's surface every year than is carried to the sea by all the world's rivers as a result of water erosion. Human activity on the planet changes the climate, affects the composition of the atmosphere and the oceans.[ ...]

IN AND. Vernadsky in the first half of the twentieth century predicted the development of the biosphere and its transition to the noosphere - the sphere of reason. Determining the current stage in the development of the biosphere and human society, we can say that technological and anthropogenic processes are playing an ever-increasing role.[ ...]

The complex hierarchical organization of living nature contains huge reserves of self-regulation. To unlock these reserves, competent intervention in the processes taking place in the biosphere is necessary. The strategy for such intervention can be determined by ecology, based on the achievements of the natural and social sciences.

Anthropoecosystem is a community of people who are in relationship with the environment.

Being the object of influence of environmental factors, a person at the same time has an impact on the environment.

The peculiarity of man as an ecological factor lies in the fact that he has a conscious, purposeful and powerful impact on nature. The energy resources of any biological species are limited, so it has limited ability to influence nature. Green plants use the energy of the Sun, others - the energy of organic substances of the previous link in the food chain. A person in the process of his mental activity creates very powerful sources of energy - nuclear and thermonuclear reactions. This expands the possibilities of man, and he becomes able to occupy any ecological space on the planet.

The peculiarity of man as an ecological factor lies in the fact that his activity is of an active creative nature. It can create an artificial environment around itself, which also distinguishes it from other environmental factors.

Factors of the natural and artificial environment constantly affect a person.

Adaptive ecological types of a person

In the process of the historical development of mankind, under the influence of various natural factors and as a result of the ecological specialization of the world's population, in different parts of the planet, adaptive(adapted) types of people.

Adaptive type - the norm of reaction, characterized by the development of physique, physiological parameters, biochemical and immunological properties, providing a better adaptation of a person to certain living conditions.

Among the most important modern anthropogenic ecosystems include cities, villages, transport communications. material from the site

urban ecosystems

The change in the natural environment is clearly manifested in cities. The accumulation of industrial and household waste leads to an increase in the content of trace elements in soil, water and plants, the high density of the urban population creates conditions for the widespread spread of infectious diseases. As a result of air pollution, a significant part of ultraviolet rays does not reach the earth's surface. Insufficient light leads to a decrease in the content of vitamin D in the body.

rural ecosystems

The widespread use of pesticides, herbicides and other chemicals in agriculture can have a detrimental effect on the health of the rural population.

The term "ecology" was introduced into science by the German scientist Ernst Haeckel (E. Haeckel) in 1869. It is quite easy to give a formal definition, since the word "ecology" comes from the Greek words "oikos" - dwelling, shelter and "logos" - science. Therefore, ecology is often defined as the science of the relationship between organisms or groups of organisms (populations, species) with their environment. In other words, the subject of ecology is a set of relationships between organisms and the conditions of their existence (environment), on which the success of their survival, development, reproduction, distribution, and competitiveness depend.

In botany, the term "ecology" was first used by the Danish botanist E. Warming in 1895.

In a broad sense, the environment (or environment) is understood as the totality of material bodies, phenomena and energy, waves and fields, one way or another affecting. However, different environments are far from equally perceived by a living organism, since their significance for life is different. Among them there are practically indifferent to plants, for example, inert gases contained in the atmosphere. Other elements of the environment, on the contrary, have a noticeable, often significant effect on the plant. They are called environmental factors. These are, for example, light, water in the atmosphere and soil, air, salinization of groundwater, natural and artificial radioactivity, etc.). With the deepening of our knowledge, the list of environmental factors is expanding, since in a number of cases it is found that plants are able to respond to elements of the environment that were previously considered indifferent (for example, a magnetic field, strong noise exposure, electric fields, etc.).

Classification of environmental factors

It is possible to classify environmental factors in different conceptual coordinate systems.

Distinguish, for example, resource and non-resource environmental factors. Resource factors are substances and (or) involved in the biological cycle by the plant community (for example, light, water, the content of mineral nutrients in the soil, etc.); accordingly, non-resource factors do not participate in the cycles of matter and energy transformation and ecosystems (for example, relief).

There are also direct and indirect environmental factors. The former directly affect metabolism, shaping processes, growth and development (light), the latter affect the body through a change in other factors (for example, transabiotic and transbiotic forms of interactions). Since in different ecological situations many factors can act both directly and indirectly, it is better to speak not about the separation of factors, but about their direct or indirect effect on the plant.

The most widely used classification of environmental factors according to their origin and nature of action:

I. Abiotic factors:

a) climatic - light, heat (its composition and movement), moisture (including precipitation in various forms, air humidity), etc .;

b) edaphic (or soil-ground) - physical (granulometric composition, water permeability) and chemical (pH of soils, content of mineral nutrition elements, macro- and microelements, etc.) properties of soils;

c) topographic (or orographic) - relief conditions.

II. Biotic factors:

a) phytogenic - direct and indirect impact of plant cohabitants;

b) zoogenic - direct and indirect influence of animals (eating, trampling, digging activities, pollination, distribution of fruits and seeds);

c) prokaryotic factors - the influence of bacteria and blue-green algae (negative effect of phytopathogenic bacteria, positive effect of free-living and symbiotically associated nitrogen-fixing bacteria, actinomycetes and cyanides);

Read more about biotic factors in the article

Specific forms of human impact on the vegetation cover, their direction, and scale make it possible to single out anthropogenic factors as well.

III. Anthropogenic factors associated with the multilateral forms of human agricultural activity (grazing, haymaking), its industrial activity (gas emissions in, construction, mining, transport communications and pipelines), with space exploration and recreational activities.

Far from everything fits into this simplest classification, but only the main environmental factors. There are other plants that are less essential for life (atmospheric electricity, the Earth's magnetic field, ionizing radiation, etc.).

We note, however, that the above division is to a certain extent conditional, since (and this is important to emphasize both in theoretical and practical terms) the environment affects the organism as a whole, and the separation of factors and their classification is nothing more than a methodological technique, facilitating the knowledge and study of the patterns of relationships between the plant and the environment.

General patterns of influence of environmental factors

The influence of environmental factors on a living organism is very diverse. Some factors - leading ones - have a stronger effect, others - secondary ones - act weaker; some factors affect all aspects of plant life, others - on any particular life process. Nevertheless, it is possible to present a general scheme of the dependence of the body's reaction under the influence of an environmental factor.

If the intensity of the factor in its physical expression is plotted along the abscissa (X) axis ( , salt concentration in the soil solution, pH, illumination of the habitat, etc.), and along the ordinate (Y) - the reaction of the organism or population to this factor in its quantitative expression (intensity of one or another physiological process - photosynthesis, water absorption by roots, growth, etc.; morphological characteristic - plant height, leaf size, number of seeds produced, etc.; population characteristics - number of individuals per unit area , frequency of occurrence, etc.), we get the following picture.

The range of the ecological factor (the area of ​​tolerance of the species) is limited by the minimum and maximum points, which correspond to the extreme values ​​of this factor, at which the existence of the plant is possible. The point on the abscissa axis, corresponding to the best indicators of the plant's vital activity, means the optimal value of the factor - this is the optimum point. Due to the difficulties in accurately determining this point, one usually speaks of a certain optimum zone, or a comfort zone. The optimum, minimum, and maximum points make up three cardinal points that determine the possibilities of a species' reaction to a given factor. The extreme sections of the curve, expressing the state of oppression with a sharp lack or excess of the factor, are called areas of pessimum; they correspond to the pessimal values ​​of the factor. Sub-lethal values ​​of the factor lie near the critical points, and lethal values ​​lie outside the tolerance zone.

Species differ from each other by the position of the optimum within the gradient of the ecological factor. For example, the attitude to heat in arctic and tropical species. The width of the range of the factor (or optimum zone) can also be different. There are species, for example, for which a low level of illumination (cave bryophytes) or a relatively high level of illumination (alpine alpine plants) is optimal. But species are also known that grow equally well both in full light and in significant shading (for example, the team hedgehog - Dactylis glomerata).

In the same way, some meadow grasses prefer soils with a certain, rather narrow range of acidity, while others grow well in a wide pH range - from strongly acidic to alkaline. The first case testifies to a narrow ecological amplitude of plants (they are stenobiont or stenotopic), the second - to a wide ecological amplitude (plants are eurybiont or eurytopic). Between the categories of eurytopicity and stenotopicity lies a number of intermediate qualitative categories (hemieurytopic, gemistenotopic).

The breadth of the ecological amplitude in relation to different environmental factors is often different. It is possible to be stenotopic with respect to one factor and eurytopic with respect to another: for example, plants can be confined to a narrow range of temperatures and a wide range of salinity.

Interaction of environmental factors

Environmental factors act on the plant jointly and simultaneously, and the effect of one factor depends to a large extent on the "ecological background", that is, on the quantitative expression of other factors. This phenomenon of interaction of factors is clearly seen in the experiment with the aquatic moss Fontinalis. This experiment clearly shows that illumination has a different effect on the intensity of photosynthesis at different CO 2 content in .

The experiment also shows that a similar biological effect can be obtained by partially replacing the action of one factor with another. Thus, the same intensity of photosynthesis can be achieved either by increasing the illumination to 18 thousand lux, or, at lower illumination, by increasing the concentration of CO 2 .

Here, the partial interchangeability of the action of one environmental factor with another is manifested. At the same time, none of the necessary environmental factors can be replaced by another: a green plant cannot be grown in complete darkness even with very good mineral nutrition or on distilled water with optimal thermal conditions. In other words, there is a partial substitution of the main ecological factors and, at the same time, their complete indispensability (in this sense, they are sometimes also spoken of as equally important for plant life). If the value of at least one of the necessary factors goes beyond the tolerance range (below the minimum and above the maximum), then the existence of the organism becomes impossible.

Limiting factors

If any of the factors that make up the conditions of existence has a pessimal value, then it limits the effect of the remaining factors (no matter how favorable they may be) and determines the final result of the environment's action on the plant. This end result can only be changed by acting on the limiting factor. This "law of the limiting factor" was first formulated in agricultural chemistry by the German agricultural chemist, one of the founders of agricultural chemistry, Justus Liebig in 1840 and is therefore often called Liebig's law.

He noticed that with a lack of one of the necessary chemical elements in the soil or nutrient solution, no fertilizers containing other elements affect the plant, and only the addition of “minimum ions” gives an increase in yield. Numerous examples of the action of limiting factors, not only in experiment, but also in nature, show that this phenomenon is of general ecological significance. One example of the operation of the “law of the minimum” in nature is the suppression of herbaceous plants under the canopy of beech forests, where, under optimal thermal conditions, high carbon dioxide content, sufficiently rich soils and other optimal conditions, the possibilities for grass development are limited by a sharp lack of light.

The identification of "factors at a minimum" (and at a maximum) and the elimination of their limiting effect, in other words, the optimization of the environment for plants, constitute an important practical task in the rational use of vegetation cover.

Autecological and synecological range and optimum

The attitude of plants to environmental factors closely depends on the influence of other plant co-habitants (primarily on competitive relations with them). Often there is a situation when a species can successfully grow in a wide range of action of some factor (which is determined experimentally), but the presence of a strong competitor forces it to be limited to a narrower zone.

For example, Scotch pine (Pinus sylvestris) has a very wide ecological range in relation to soil factors, but in the taiga zone it forms forests mainly on dry, poor sandy soils or on highly waterlogged peatlands, i.e., where there are no competing tree species. Here, the real position of the optima and areas of tolerance is different for plants that experience or do not experience biotic influence. In this regard, a distinction is made between the ecological optimum of a species (in the absence of competition) and the phytocenotic optimum corresponding to the actual position of the species in the landscape or biome.

In addition to the position of the optimum, the limits of the endurance of the species are distinguished: the ecological range (the potential limits of the distribution of the species, determined only by its relation to this factor) and the real phytocenotic range.

Often in this context one speaks of a potential and real optimum and range. In foreign literature, they also write about the physiological and ecological optimum and range. It is better to talk about the autecological and synecological optimum and the range of the species.

In different species, the ratio of the ecological and phytocenotic ranges is different, but the ecological range is always wider than the phytocenotic one. As a result of the interaction of plants, the range narrows and often the optimum shifts.