Environmental factors

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 impact environment, which can have a direct or indirect impact 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 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, on a par 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 with 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 reproductive period or at an early stage of development are 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 required, 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 factors external environment.

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 various factors environment, 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, the 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 recent decades, the term anthropogenic factors has been increasingly 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 modification of 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 environment;

Thermal pollution of the environment;

Deformity visible environment(changes in terrain and color range in populated areas).

Chemical factors.

Natural chemical factors include:

Chemical composition of the lithosphere:

Chemical composition of the hydrosphere;

Chemical atmospheric composition,

Chemical composition of food.

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

Anthropogenic chemical factors:

Household waste,

Industrial waste,

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

Pharmaceutical industry products,

Food additives.

Action chemical factors on the human body may 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 determined entirely by biological and psychological properties. 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 conduct, 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 politics, forming 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 a combination of factors in the social environment.

Sociotype includes:

2. working conditions, recreation and life.

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 impacts 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 - isolated by demographic characteristics groups, fourth - 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 labor activity:

Profession,

Sanitary and hygienic working conditions,

The presence of occupational hazards,

Psychological microclimate at work,

6. Family and household factors:

Family composition,

The nature of the housing

Average income per 1 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. Availability bad habits and dependencies.

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

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

In a broad sense, the medium (or environment) is understood as a set of material bodies, phenomena and energy, waves and fields that in one way or another influence. However, different environments are far from being perceived equally 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 in the 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 some cases it is discovered 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

Environmental factors can be classified in different conceptual coordinate systems.

There are, 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, content of mineral nutrition elements in the soil, etc.); Accordingly, non-resource factors do not participate in cycles of transformation of matter and energy and ecosystems (for example, relief).

There are also direct and indirect environmental factors. The former directly affect metabolism, morphogenesis processes, growth and development (light), the latter affect the body through changes in other factors (for example, transabiotic and transbiotic forms of interactions). Since in different environmental situations many factors can act both directly and indirectly, it is better to talk 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 is:

I. Abiotic factors:

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

b) edaphic (or soil-soil) - physical (particle-size composition, water permeability) and chemical (soil pH, 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 effects of co-inhabiting plants;

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

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

You can read more about biotic factors in the article

Specific forms of human impact on vegetation, their direction, and scale make it possible to identify anthropogenic factors.

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

Not everything fits into this simple 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 and etc.).

Let us note, however, that the above division is to a certain extent arbitrary, since (and this is important to emphasize both theoretically and practically) the environment affects the organism as a whole, and the separation of factors and their classification is nothing more than a methodological technique, facilitating knowledge and study of the patterns of relationships between plants 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 - have a stronger impact, others - secondary - have a weaker effect; Some factors influence all aspects of a plant’s life, others influence any specific life process. Nevertheless, it is possible to imagine a general diagram 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 ( , concentration of salts in the soil solution, pH, illumination of the habitat, etc.), and along the ordinate axis (Y) - the reaction of the organism or population to this factor in its quantitative expression (intensity of a particular physiological process - photosynthesis, water absorption by roots, growth, etc.; morphological characteristics - 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 action of the environmental 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 plant’s existence is possible. The point on the x-axis corresponding to the best performance indicators of the plant means the optimal value of the factor - this is the optimum point. Due to difficulties in precise definition This point is usually spoken of as a certain optimum zone, or comfort zone. The points of optimum, minimum and maximum constitute three cardinal points that determine the possibility of a species’ reaction to a given factor. The extreme sections of the curve, expressing the state of oppression with a sharp deficiency or excess of a factor, are called pessimum areas; they correspond to the pessimal values ​​of the factor. Near the critical points there are sublethal values ​​of the factor, and outside the tolerance zone there are lethal values.

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

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

The breadth of 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 influence the plant jointly and simultaneously, and the effect of one factor largely depends on the “ecological background,” i.e., on the quantitative expression of other factors. This phenomenon of interaction of factors is clearly illustrated by the example of an 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 contents.

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 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 with distilled water under optimal thermal conditions. In other words, there is a partial replaceability of the main environmental factors and at the same time their complete irreplaceability (in this sense, they are sometimes also said to be of equal importance for the life of a plant). 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 action of the remaining factors (no matter how favorable they may be) and determines the final result of the action of the environment on the plant. This end result can only be changed by influencing the limiting factor. This “limiting factor law” 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 if there is a deficiency of one of the necessary chemical elements in the soil or nutrient solution, no fertilizers containing other elements have an effect on 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 has 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, increased carbon dioxide content, sufficiently rich soils and other optimal conditions, the possibilities for the development of grasses are limited by a sharp lack of light.

Identifying “factors at a minimum” (and at a maximum) and eliminating their limiting effect, in other words, optimizing the environment for plants, constitutes an important practical task in the rational use of vegetation cover.

Autecological and synecological area and optimum

The attitude of plants to environmental factors closely depends on the influence of other plant-inhabitants (primarily on competitive relations with them). Often there is a situation where 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, Scots 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 heavily waterlogged peatlands, i.e., where there are no competing tree species. Here, the actual position of optima and tolerance areas is different for plants that do 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, which corresponds to the actual position of the species in the landscape or biome.

In addition to the optimum position, the endurance limits of a species are distinguished: the ecological area (the potential limits of the species' distribution, determined only by its relationship to a given factor) and the actual phytocenotic area.

Often in this context they talk about potential and actual optimum and range. IN foreign literature They also write about the physiological and ecological optimum and habitat. It is better to talk about the autecological and synecological optimum and the range of the species.

For different species, the ratio of ecological and phytocenotic areas is different, but the ecological area is always wider than the phytocenotic area. As a result of plant interaction, a narrowing of the range and often a shift in the optimum occurs.

Environmental factors- properties of the habitat that have any effect on the body. For example, the presence of minerals, oxygen access, soil moisture, soil temperature, soil looseness. Indifferent elements of the environment, for example, inert gases, are not environmental factors.

modes

By the nature of the impact

• Direct acting
• Indirectly acting
• Conditionally valid- influence of ecosystem elements (biogeocoenosis) enhanced or weakened by the action of other environmental factors

By origin

• Abiotic- factors of inanimate nature:
  • climatic
  • edaphic (edaphogenic)
  • orographic
  • chemical
  • physical: noise, magnetic fields, thermal conductivity and heat capacity, radioactivity, solar radiation intensity ***** hydrographic: water density, current, transparency, etc.
    • pyrogenic: fire factors[ source not specified 824 days] (Odum, 1975, 1986)
• Biotic
  • phytogenic- influence of plants
  • mycogenic- influence of mushrooms
  • zoogenic- influence of animals
  • microbiogenic- influence of microorganisms
• Anthropogenic (anthropic) factor:
  • In 1912, the Russian scientist prof. G.F. Morozov in his book “The Study of Forests” defined the human impact on nature as a separate environmental factor and divided it according to the nature of the influence on the natural environment into direct, indirect and conditional anthropogenic impact [Morozov, 1949].
  • Direct anthropogenic impact– direct human influence on the components of the ecosystem (biogeocenosis). This includes picking berries, mushrooms, cutting down trees, etc.
  • Indirect anthropogenic impact– human influence through the intermediate level. This is a change in groundwater level, a change temperature regime, radiation pollution, etc.
  • Conditional anthropogenic impact is the influence of biotic and abiotic factors, strengthened or weakened by human influence.
  • In 1981, the definition “Anthropogenic factor [anthropogenic impact] is any impact on the environment [natural] environment associated with both conscious and unconscious human activity, leading to quantitative and qualitative changes in its components [Popa, 1981].
  • In 2011, a scale of anthropogenic digression of biogeocenoses (ecosystems), developed using the example of broad-leaved forests of the steppe zone, was published, including 12 stages of destruction of the natural environment by humans, from the state of conditionally undisturbed ecosystems to the stage of complete loss of vital functions by biogeocenoses [Popa, 2011].

By spending

• Resources
• Conditions

By direction

• Vectorized
• Perennial-cyclical

• Monodominance
• Synergy
• Antagonism
• Provocativeness

extreme values

Life curve of a perennial plant. Annual plants are not able to go into a dormant state and their zone of life coincides with the zone of vital activity.

plastic

life curve points And zones:

• Cardinal points:
  • points minimum And maximum
  • dot optimum
• Zones:
  • zone optimum
  • zones pessimum
  • zone vital activity
  • zones peace
  • zone life

reaction norm

abundance or frequency of occurrence

Bibliography

• Sahney, S., Benton, M.J. and Ferry, P.A. (2010). “Links between global taxonomic diversity, ecological diversity and the expansion of vertebrates on land” (PDF). Biology Letters 6 (4): 544–547. DOI:10.1098/rsbl.2009.1024. PMID 20106856.
• David L. Hawksworth. Biodiversity and Conservation in Europe. - Springer, 2008. - P. 3390. - ISBN 1402068646..
• Bampton, M. "Anthropogenic Transformation" in Encyclopedia of Environmental Science, D. E. Alexander and R. W. Fairbridge, Kluwer Academic Publishers, Dordrecht, The Netherlands.
• Worm, Boris (2006-11-03). "Impacts of Biodiversity Loss on Ocean Ecosystem Services." Science 314 (5800): 787–790. DOI:10.1126/science.1132294. PMID 17082450.
• Morozov G.F. Teaching about the forest. 7th edition. M.: Goslesbumizdat, 1949. 455 p.
• Popa Yu.N Anthropogenic transformation of forest biogeocenoses in Kodr of Moldova. Author's abstract. dis. Ph.D. biol. Sciences:03.00.16 - Ecology. Krasnoyarsk, 1981. p.6.
• Popa Yu.N. Restoration of biogeocenoses in anthropogenically transformed ecotopes in the steppe zone: monograph. edited by member-corr. NAS of Ukraine, Doctor of Biology. sciences, prof. A. P. Travleeva; National Aviation University. - Kyiv: Ukrainian bestseller, 2011. - 437 p.

Environmental factors

Adaptation of organisms to the environment

Basic living environments

Environmental factors

Organism and environment

Lecture 6. Fundamentals of autecology. Organism and environment

Autecology studies the relationship between representatives of one species and its environment. Based on the study of the processes of adaptation of species to the environment (factorial ecology). Human ecology also studies the influence (normalization) of environmental factors and its extreme effects on the body.

The living world around us consists of organisms that constantly reproduce themselves. One aphid can leave more than 300 million offspring over the summer. The ability to reproduce indefinitely is inherent. But there is no unlimited growth in numbers; the main limiter is the lack of resources. For plants - mineral salts, carbon dioxide, water, light. For animals - food, water. reserves of these resources inhibit reproduction. The second limiter is the influence of various unfavorable conditions, which slow down growth and reproduction. Plant growth depends on the weather. The reproduction of aquatic inhabitants is inhibited by the low oxygen content in the water. In addition, the elimination and death of already produced embryos or young individuals occurs. For example, not all acorns germinate. High fertility is distinguished by species in which the death of individuals in nature is very high.

The body, experiencing the need for an influx of energy and information, is completely dependent on the environment

Law - the results of the development of an organism are determined by the ratio of its internal features and the characteristics of the environment in which it is located.

An evolutionary adaptation of organisms to environmental conditions, expressed in changes in their external and internal characteristics - adaptation. Le Chatelier's principle: “The evolution of any system goes in the direction of reducing potential danger.” According to this principle, the evolution of an organism contributes to its adaptation to changing external influences.

Environmental factors– these are certain conditions and elements of the environment that have a specific effect on the body.

Environmental factors: 1- abiotic. 2 – biotic. 3- anthropogenic.

Abiotic factors– a set of factors in the inorganic environment that influence the life and distribution of animals and plants

Abiotic factors

physical chemical edaphic (soil)

Biotic factors– the totality of influences of the life activity of some organisms on the life activity of others, as well as on the inanimate environment

Biotic factors

intraspecific interspecific influence on

interactions interactions abiotic factors

(commonwealth)

Commensalism

(one benefits)

Amensalism

(one species inhibits the growth of another)

Anthropogenic factors– factors generated by man and affecting the environment (pollution, soil erosion, destruction of forests, etc.)

The general nature of the action of environmental factors.

In the life process, the interaction of organisms with their habitat and its components among themselves is based on the transfer of mass flows of matter and their compounds, energies of all types and information between the elements of the system. In accordance with the law of conservation of life by Yu. N. Kurazhkovsky: “Life can only exist in the process of movement of flows of matter, energy and information through a living body.”

The interaction of an organism with its environment is subject to the following laws. Main Law optimum (tolerance). Liebig's Law It is expressed in the fact that any environmental factor has certain limits of positive influence on the body. When deviating from these limits, the sign of the effect changes to the opposite. For example, animals do not tolerate heat and severe frosts well; Drought and heavy rains are unfavorable for the crop. The optimum curves for any factor will not coincide for different species. Camels and jerboas do not tolerate the conditions of the northern deserts, and reindeer and lemmings do not tolerate the hot southern ones. A number of species can live within a narrow range of optimum, while others can live within a wide range. The impatiens plant dies if there is no moisture in the air; the feather grass does not die even in drought. The optimum and limits of endurance are not constant throughout the life of the organism. The optimum can be shifted (temperature hardening).

In accordance with the rule of optimum for an organism, there is a range of the most favorable (optimal) factor value. Beyond the optimum there are zones of oppression that turn into critical points. For some organisms, the optimum zone has a wide range. They're called - eurybionts(Greek: wide, life). Organisms with a narrow range – stenobionts(narrow).

The range of factor values ​​(between critical points) is called ecological valence. Synonymous with valency tolerance.( lat tolerance - patience), or plasticity (variability) if the environment is relatively constant, little variable, then there are more stenobionts in it (for example, in an aquatic environment). If the environment is dynamic, for example, water-air, eurybionts have a greater chance of survival in it. The optimum zone and ecological valence are wider in warm-blooded animals.

Effect of temperature factor. If the range of tolerance lies within a wide range (-5; +25), then such organisms are called eurythermal, if narrow - stenothermic. May be euryhaline (salinity)

Rice. 1. Dependence of life potential on the intensity of the impact factor

1. – zone of optimum (comfort);

2. – zone of permissible life activity;

3. – zone of oppression;

4. – death zone.

Tolerance – the body’s ability to tolerate the adverse effects of one or another environmental factor.

Optimum zone with a point of comfort (the point of maximum - life potential) - the area of ​​​​optimal life activity.

Zones of permissible living activity – the values ​​of the permissible values ​​of the impact factor are the area of ​​normal life activity.

Zones of oppression – zones with large deviations of the factor from the optimum, in which the body experiences suppression of vital functions.

Death zone – the limits of tolerance for the impact factor coincide with the values ​​of the minimum and maximum of the factor, beyond which the existence of the organism is not possible.

It must be taken into account that some factors can enhance or mitigate the effect of others. Excess heat can be mitigated by low air humidity. . The law of independence of factors by V. R. Williams: “Life conditions are equivalent, none of the factors of life can be replaced by another”

2nd law – limiting factor. The most significant factor is the one that deviates the most from the optimal values. A factor that is in deficiency or excess (near critical points) negatively affects the body. Limiting factors determine the boundaries of species distribution - range. The productivity of organisms and communities depends on them.

Limiting factor rule in agronomy. If the soil lacks mineral salts (50% phosphorus, 20% calcium), the harvest will be 5 times less. If you add calcium, the yield is 59%.

Human activity often violates all the laws of action of factors - habitat destruction, disruption of water and mineral nutrition.

The law of optimum and limiting factor can be expressed in one law W. Shelford's law of tolerance:“The limiting factor for the prosperity of a population (organism) can be either a minimum or maximum environmental impact, and the range between them determines the amount of endurance (tolerance limit) of the organism to a given factor”

Environmental factors are:

Environmental factors

Environmental factors- properties of the habitat that have any effect on the body. Indifferent elements of the environment, for example, inert gases, are not environmental factors.

Environmental factors exhibit significant variability in time and space. For example, temperature varies greatly on the surface of land, but is almost constant at the bottom of the ocean or deep in caves.

The same environmental factor has different meaning in the life of co-living organisms. For example, the salt regime of the soil plays a primary role in the mineral nutrition of plants, but is indifferent to most terrestrial animals. The intensity of illumination and the spectral composition of light are extremely important in the life of phototrophic organisms (most plants and photosynthetic bacteria), and in the life of heterotrophic organisms (fungi, animals, a significant part of microorganisms) light does not have a noticeable effect on life activity.

Environmental factors can act as irritants that cause adaptive changes in physiological functions; as limiters that make it impossible for certain organisms to exist under given conditions; as modifiers that determine morpho-anatomical and physiological changes in organisms.

Organisms are not influenced by static, unchanging factors, but by their modes- sequence of changes over a certain time.

Classifications of environmental factors

By the nature of the impact

• Direct acting- directly affecting the body, mainly on metabolism
• Indirectly acting- influencing indirectly, through changes in directly acting factors (relief, exposure, altitude, etc.)

By origin

• Abiotic- factors of inanimate nature:
  • climatic: annual sum of temperatures, average annual temperature, humidity, air pressure
  • edaphic (edaphogenic): soil mechanical composition, soil breathability, soil acidity, soil chemical composition
  • orographic: relief, altitude, steepness and aspect of the slope
  • chemical: gas composition of air, salt composition of water, concentration, acidity
  • physical: noise, magnetic fields, thermal conductivity and heat capacity, radioactivity, solar radiation intensity
• Biotic- related to the activities of living organisms:
  • phytogenic- influence of plants
  • mycogenic- influence of mushrooms
  • zoogenic- influence of animals
  • microbiogenic- influence of microorganisms
• :
  • physical: use of nuclear energy, travel on trains and planes, influence of noise and vibration
  • chemical: use of mineral fertilizers and pesticides, pollution of the Earth’s shells with industrial and transport waste
  • biological: Food; organisms for which humans can be a habitat or source of food
  • social- related to relationships between people and life in society

By spending

• Resources- elements of the environment that the body consumes, reducing their supply in the environment (water, CO 2, O 2, light)
• Conditions- environmental elements not consumed by the body (temperature, air movement, soil acidity)

By direction

• Vectorized- directionally changing factors: waterlogging, soil salinization
• Perennial-cyclical- with alternating multi-year periods of strengthening and weakening of the factor, for example climate change in connection with the 11-year solar cycle
• Oscillatory (impulse, fluctuation)- fluctuations in both directions from a certain average value (daily fluctuations in air temperature, changes in the average monthly precipitation throughout the year)

The effect of environmental factors on the body

Environmental factors affect the body not individually, but in combination; accordingly, any reaction of the body is multifactorially determined. At the same time, the integral influence of factors is not equal to the sum of the influences of individual factors, since between them there are various kinds interactions, which can be divided into four main types:

• Monodominance- one of the factors suppresses the action of the others and its magnitude is of decisive importance for the body. So, complete absence, or the presence of mineral nutrition elements in the soil in a sharp deficiency or excess prevents the normal absorption of other elements by plants.
• Synergy- mutual reinforcement of several factors due to positive feedback. For example, soil moisture, nitrate content and illumination, while improving the provision of any of them, increase the effect of the other two.
• Antagonism- mutual suppression of several factors due to negative feedback: an increase in the locust population contributes to a decrease in food resources and its population declines.
• Provocativeness- a combination of positive and negative influences for the body, with the influence of the latter enhanced by the influence of the former. So, the earlier the thaw occurs, the more the plants suffer from subsequent frosts.

The influence of factors also depends on the nature and current state of the body, therefore they have different effects on both different types, and on one organism at different stages of ontogenesis: low humidity is destructive for hydrophytes, but harmless for xerophytes; low temperatures are tolerated without harm by adult conifers of the temperate zone, but are dangerous for young plants.

Factors can partially replace each other: when illumination decreases, the intensity of photosynthesis will not change if the concentration of carbon dioxide in the air increases, which usually happens in greenhouses.

The result of the influence of factors depends on the duration and repetition of their action extreme values throughout the life of the organism and its descendants: short-term exposures may not have any consequences, while long-term ones through the mechanism natural selection lead to qualitative changes.

The body's response to changes in environmental factors

Life curve of a perennial plant. Annual plants are not able to go into a dormant state and their zone of life coincides with the zone of vital activity.
Note: 1 - optimum point, 2 - minimum and maximum points, 3 - lethal points

Organisms, especially those leading an attached life, like plants, or a sedentary lifestyle, are characterized by plastic- the ability to exist in more or less wide ranges of environmental factors. However, at different values ​​of the factor, the body behaves differently.

Accordingly, its value is identified in which the body will be in the most comfortable state - quickly grow, reproduce, and demonstrate competitive abilities. As the factor value increases or decreases relative to the most favorable one, the body begins to experience depression, which manifests itself in a weakening of its vital functions and, at extreme values ​​of the factor, can lead to death.

Graphically, a similar reaction of the body to a change in factor values ​​is depicted in the form life curve(ecological curve), when analyzing which we can highlight some points And zones:

• Cardinal points:
  • points minimum And maximum - extreme values ​​of the factor at which the vital activity of the organism is possible
  • dot optimum - the most favorable factor value
• Zones:
  • zone optimum - limits the range of the most favorable factor values
  • zones pessimum (upper and lower) - ranges of factor values ​​in which the body experiences strong depression
  • zone vital activity - the range of factor values ​​in which it actively manifests its vital functions
  • zones peace (upper and lower) - extremely unfavorable values ​​of the factor, at which the organism remains alive, but goes into a state of rest
  • zone life - the range of factor values ​​in which the organism remains alive

Beyond the boundaries of the life zone there are lethal values ​​of the factor at which the organism is not able to exist.

Changes that occur in an organism within the range of plasticity are always phenotypic, while the genotype encodes only a measure of possible changes - reaction norm, which determines the degree of plasticity of the organism.

Based on the individual life curve, it is possible to predict the species life curve. However, since a species is a complex supraorganismal system consisting of many populations distributed in different habitats with different environmental conditions, when assessing its ecology, generalized data are used not for individual individuals, but for entire populations. On the gradient of a factor, generalized classes of its values ​​are deposited, representing certain types of habitats, and environmental reactions are most often considered abundance or frequency of occurrence kind. In this case, we should no longer talk about a vital activity curve, but about a distribution curve of abundances or frequencies.

Section 1. Theoretical aspects of ecology

Topic 1.1. Autoecology (factorial ecology)

Autoecology is a branch of ecology that studies the relationship of an organism with the environment. This section is dedicated to studying species features responses of animal and plant organisms to environmental factors and lifestyle of the species.

As part of this topic, today we will consider the following questions:

The main environments of existence of organisms

Patterns of influence of environmental factors on living organisms

Environmental factors and their classification

The concept of “habitat” differs from the concept of “living conditions” - a set of vital environmental factors without which living organisms cannot exist (light, heat, moisture, air, soil). Other environmental factors, although they have a significant impact on organisms, are not vital for them (for example, wind, natural and artificial ionizing radiation, atmospheric electricity, etc.).

2 . Any organism can exist only in a certain temperature range. When the environmental temperature is too low or too high, the organism dies. Where the temperature is close to extremes, representatives of this species are rare, but as the temperature approaches the average value optimal for them, their number increases. This pattern is true for any other factor a, affecting the course of certain life processes (humidity, wind strength, current speed, etc.).

If you draw a curve on a graph that characterizes the speed of a particular process (breathing, movement, nutrition, etc.) depending on one of the environmental factors (of course, provided that this factor influences the main life processes), then this curve will almost always be bell-shaped (Fig. 1). Such curves are called tolerance curves (from the Latin tolerahtia - patience). The position of their top indicates the conditions that are optimal for a given process. Some species are characterized by curves with very sharp peaks; this means that the range of optimal conditions for them is very narrow. Smooth curves correspond to a wide range of tolerance, i.e. resistance to a given factor.

Organisms with wide limits of resistance to many factors, of course, have a chance of becoming more widespread.

In widespread species populations, living in climatically different zones, often turn out to be best adapted specifically to the conditions of a given area. This is due to their ability to form local forms, or ecotypes, characterized by different limits of resistance to temperature, light or other factors.

As an example, consider the ecotypes of one of the jellyfish species. As you know, jellyfish move through water like a rocket - using rhythmic contractions muscles, pushing water out of the central cavity. The optimal pulsation speed is 15-20 contractions per minute. Individuals of one species of jellyfish living in northern latitudes move at the same speed as jellyfish of the same species in southern latitudes, although the water temperature in the north can be 20 C lower. This means that both forms of jellyfish were able to best adapt to local conditions.

Law of the minimum.

The intensity of certain biological processes often turns out to be sensitive to two and more environmental factors. In this case, the decisive factor will be the one that is available in the minimum amount from the point of view of the body’s needs. This simple rule was first formulated by the founder of the science of mineral fertilizers by the German chemist and agricultural chemist Justus Liebig (1803-1873) and was named law of the minimum . Yu. Liebig discovered that plant yield can be limited by one - any - of the basic nutritional elements, unless this element is lacking in the soil.

Different environmental factors can interact, i.e., a lack of one substance can lead to a deficiency in other substances. For example, a lack of moisture in the soil limits the supply of all other substances necessary for their nutrition to plants. Therefore, in general, the law of minimum can be formulate as follows : the successful survival of living organisms depends on a set of conditions; a limiting, or limiting, factor is any state of the environment that approaches or goes beyond the stability limit for. organisms of this species.

Environmental factors. Elements of the environment that cause adaptive reactions (adaptations) in living organisms and their communities are called environmental factors.

By origin and nature of action, environmental factors classified: abiotic (elements of inorganic, or nonliving, nature); biotic (forms of influence of living beings on each other); anthropogenic ( all forms of human activity that influence living things family).

Abiotic factors are divided into physical , or climatic (light, air and water temperature, air and soil humidity, wind); edaphic, or soil-ground (mechanical composition of soils, their chemical and physical properties); topographical, or orographic (features of the terrain); chemical

Anthropogenic (anthropogenic) factors are all forms of activity of human society that change nature as the habitat of living organisms or directly affect their lives. The separation of anthropogenic factors into a separate group is due to the fact that currently the fate of the Earth's vegetation and all currently existing species of organisms is practically in the hands of human society.

Environmental factors affect organisms in different ways. They can act as irritants, causing adaptive changes in physiological functions; How limiters, causing the impossibility of the existence of certain organisms in given conditions; How modifiers,

/ ecology 1 lecture

Lecture 1

BASICS OF ECOLOGY

Subject, tasks and methods of ecology

Habitat and living conditions of organisms

Environmental factors

Patterns of action of environmental factors on the body

Interaction of environmental factors

Influence of main abiotic factors on living organisms

Biotic environment.

Trophic (food) chain

Forms of biotic relationships.

Energy cycles in ecosystems

Subject, tasks and methods of ecology .Ecology(Greek, oikos - dwelling, residence, logos - science) - biological science about the relationships between living organisms and their habitats. This term was proposed in 1866. German zoologist Ernst Haeckel.

Area(Latin area - area, space) - part of the surface of land or water area within which individuals of a given species (genus, family or certain type of community) are distributed and undergo the full cycle of their development.

Ecological objects are predominantly systems above the level of organisms, i.e. the study of the organization and functioning of supraorganismal systems: populations, biocenoses(communities), biogeocenoses(ecosystems) and biosphere generally. In other words, the main object of study in ecology is ecosystems, i.e., unified natural complexes formed by living organisms and their habitat.

Population- (Latin populus - people, population). a grouping of individuals of the same species, inhabiting a certain part of the range for a long time, freely interbreeding and relatively isolated from other groups of the same species, is called a population

View- a group of organisms that have common features in the structure of the body, physiology and methods of relationship with the environment, capable of interbreeding with each other to form fertile offspring, but not able to do this with organisms of other species.

Biocenosis- a set of organisms inhabiting an ecosystem, interconnected by metabolism, energy and information.

Biogeocenosis - ecosystem

Biosphere, according to V.I. Vernadsky’s definition, this is the environment of our life, this is the “nature” that surrounds us.

Biosphere component of the city includes, in addition to humans, all types of green spaces and urban animal populations. (pigeons, sparrows, crows, jackdaws, waterfowl, wintering in thawed areas of water bodies, rats and mice, “domesticated” insects such as flies, mosquitoes, fleas and cockroaches, bedbugs, and finally, the microbial and viral population of multi-story buildings and city apartments).

home theoretical and practical task of ecology- to uncover general patterns of life organization and on this basis develop principles rational use natural resources in conditions of increasing human influence on the biosphere.

The most important problem of our time interaction between human society and nature, since the situation that develops in the relationship between man and nature often becomes critical. Supplies are running out fresh water

and minerals (oil, gas, non-ferrous metals, etc.), the condition of soils, water and air basins is deteriorating, desertification of vast territories is occurring, and the fight against diseases and pests of agricultural crops is becoming more complicated. Anthropogenic changes affected almost all ecosystems of the planet, the gas composition of the atmosphere, and the energy balance of the Earth. It means that human activity has come into conflict with nature , resulting in many areas of the world violated her.

dynamic equilibrium For solutions these global problems and above all, ecology unites the problems of intensification and rational use, conservation and reproduction of biosphere resources in scientific research the efforts of all specialists in biology. The range of environmental problems also includes issues environmental education, and education moral, ethical, philosophical and even legal issues . Consequently, ecology becomes science not only biological , but also

social. Ecological methods

are divided into: field

(study of the life of organisms and their communities in natural conditions, i.e. long-term observation in nature using various equipment) and experimental

At the same time, ecologists operate not only biological, but also modern physical and chemical methods , use modeling of biological phenomena, i.e., reproduction in artificial ecosystems of various processes occurring in living nature. Through simulation, you can study the behavior of any system in order to evaluate possible consequences application of various strategies and methods of resource management, i.e. for environmental forecasting.

It is also widely used to study and predict natural processes. method mathematical modeling . Such ecosystem models are built on the basis of numerous information accumulated in field and laboratory conditions.

At the same time, correctly constructed mathematical models help see what which is difficult or impossible to test experimentally. The combination of field and experimental research methods allows the ecologist to clarify all aspects of the relationship between living organisms and numerous environmental factors, which will not only restore the dynamic balance of nature, but also manage ecosystems.

Habitat and living conditions of organisms . Part of nature (a set of specific abiotic and biotic conditions) that directly surrounds living organisms and has a direct or indirect effect on their condition, growth, development, reproduction, survival called habitat.

From the concept " habitat"It is necessary to distinguish the concept " conditions of existence" - This a set of vital environmental factors without which living organisms cannot exist(light, heat, moisture, air, soil). In contrast, other environmental factors, although they have a significant impact on organisms, are not vital for them (for example, wind, natural and artificial ionizing radiation, atmospheric electricity, etc.).

Environmental factors - This elements of the environment that cause adaptive reactions (adaptations) in living organisms and their communities.

Based on their origin and nature of action, environmental factors are divided into abiotic(elements of inorganic, or nonliving, nature), biotic(forms of influence of living beings on each other) and anthropogenic(all forms of human activity that affect living nature).

Abiotic factors divided by physical, or climatic(light, air temperature and water, air and soil humidity, wind), edaphic, or soil-ground(mechanical composition of soils, their chemical and physical properties), topographical, or orographic(features of the terrain), chemical(salinity of water, gas composition of water and air, pH of soil and water, etc.).

Anthropogenic (anthropic) factors- This all forms of activity of human society that change nature as the habitat of living organisms or directly affect their lives. The separation of anthropogenic factors into a separate group is due to the fact that currently the fate of the Earth's vegetation and all currently existing species of organisms is practically in the hands of human society.

One and the same factor environment has different meaning in the life of co-living organisms. For example, the salt regime of the soil plays a primary role in the mineral nutrition of plants, but is indifferent to most terrestrial animals. Light intensity and the spectral composition of light is exclusively important in the life of phototrophic plants, and in the life of heterotrophic organisms (fungi and aquatic animals), light does not have a noticeable effect on their life activity.

Environmental factors are at work on organisms differently. They can act as irritants that cause adaptive changes physiological functions; How limiters, causing the impossibility of the existence of certain organisms in given conditions; How modifiers, determining morphological and anatomical changes in organisms.

Patterns of action of environmental factors on the body . The response of organisms to the influence of abiotic factors. The impact of environmental factors on a living organism is very diverse. Some factors have a stronger influence, others have a weaker effect; some influence all aspects of life, others influence a specific life process. Nevertheless, in the nature of their impact on the body and in the responses of living beings, a number of general patterns can be identified that fit into a certain general scheme of the action of an environmental factor on the life activity of the organism. The range of action of the environmental factor is limited by the corresponding extreme threshold values(minimum and maximum points) at which the existence of an organism is still possible. These points are called lower and upper limits of endurance (tolerance) living beings in relation to a specific environmental factor.

The best indicators of the body's vital functions- This dot optimum . For most organisms, determine optimal value factor with sufficient accuracy is often difficult, so it is customary to talk about optimum zone.

Extreme states of oppression of organisms with a sharp deficiency or excess factor, called regions pessimum or stress . Near critical points lie sublethal factor magnitude, A outside the survival zone - lethal.

This pattern of reaction of organisms to the influence of environmental factors allows us to consider it as a fundamental biological principle: for each species of plants and animals there is an optimum, a zone of normal life activity, pessimal zones and limits of endurance in relation to each environmental factor(Fig. 1)

7 6 2 1 3 5 8

1- optimum point; 2-3 - optimum zone ; 3-5 - 2-6 - limits of endurance (tolerance); 5.8 - 6,7 - extreme states of oppression of organisms - areas of pessimism or stress.

Different types of living organisms differ markedly from each other both in the position of the optimum and in the limits of endurance. For example, arctic foxes in the tundra can tolerate fluctuations in air temperature in the range of about 80°C (from +30 to -55°C), some warm-water crustaceans can withstand changes in water temperature in the range of no more than 6°C (from 23 to 29°C) The cyanobacterium oscillatorium, living on the island of Java in water with a temperature of 64°C, dies at 68°C within 5-10 minutes.

Organisms, for the existence of which it is necessary strictly defined, relatively constant environmental conditions, called stenobiont(Greek Stenos - narrow, bion - living), and those who live in wide range of environmental variability, - eurybiont (Greek eurys - wide). In this case, organisms of the same species can have a narrow amplitude in relation to one factor and a wide amplitude in relation to another (for example, adaptability to a narrow range of temperatures and a wide range of water salinity). In addition, the same dose of a factor can be optimal for one species, pessimal for another, and beyond the limits of endurance for a third.

The ability of organisms to adapt to a certain range of factor variability environment called ecological plasticity. This feature is one of the most important properties of all living things: by regulating their life activity in accordance with changes in environmental conditions, organisms acquire the ability to survive and leave offspring. Eurybiont organisms are environmentally friendly the most flexible, which provides them wide use, A stenobiont, on the contrary, they differ weak ecological plasticity and, as a result, usually have limited distribution areas.

Interaction of environmental factors . Environmental factors affect a living organism together and simultaneously. Wherein the action of one factor depends because with what strength and in what combination other factors act simultaneously. This pattern has received name interaction of factors. For example, heat or frost is easier to bear in dry rather than humid air. The rate of water evaporation from plant leaves (transpiration) is much higher if the air temperature is high and the weather is windy.

However, if the value of at least one of the vital environmental factors approaching to a critical value or goes beyond it(below the minimum or above the maximum), then despite the optimal combination of other conditions, individuals are at risk of death. Such factors are called limiting(limiting).

Limiting Factors environment determine the geographical range of the species. Thus, the movement of the species to the north may be limited by a lack of heat, and to areas of deserts and dry steppes - by a lack of moisture or too high temperatures. Biotic relationships can also serve as a factor limiting the distribution of organisms, for example, the occupancy of a territory by a stronger competitor or the lack of pollinators for flowering plants. Identifying limiting factors and eliminating their effects, i.e. optimizing the habitat of living organisms, is an important practical goal in increasing the productivity of agricultural crops and the productivity of domestic animals.

Influence of main abiotic factors on living organisms . Characteristics of light as an environmental factor. Live nature cannot exist without light, since solar radiation reaching the Earth’s surface is practically the only source of energy for maintaining the planet’s thermal balance, creating organic matter phototrophic organisms of the biosphere, which ultimately ensures the formation of an environment capable of satisfying the vital needs of all living beings.

Biological effect sunlight depends on its spectral composition, duration, intensity, daily and seasonal frequency.

Solar radiation is electromagnetic radiation in a wide range of waves that make up the continuous spectrum from 290 to 3,000 nm.

Ultra-violet rays(UVL) shorter than 290 nm, harmful to living organisms, are absorbed by the ozone layer and do not reach the Earth.

The lands are reached mainly infrared(about 50% of total radiation) and visible (45%) spectrum rays. UV rays having a wavelength of 290-380 nm account for 5% of the radiant energy. Long-wave UV rays, which have high photon energy, are characterized by high chemical activity. In small doses, they have a powerful bactericidal effect, promote the synthesis of certain vitamins and pigments in plants, and vitamin D in animals and humans; In addition, they cause tanning in humans, which is a protective reaction of the skin. Infrared rays with wavelengths greater than 710 nm have a thermal effect.

From an environmental point of view, the visible region of the spectrum is of greatest importance.(390-710 nm), or photosynthetically active radiation (PAR), which is absorbed by chloroplast pigments and is thus crucial in plant life. Green plants need visible light for the formation of chlorophyll, the formation of chloroplast structure; it regulates the functioning of the stomatal apparatus, affects gas exchange and transpiration, stimulates the biosynthesis of proteins and nucleic acids, and increases the activity of a number of light-sensitive enzymes. Light also affects cell division and elongation, growth processes and plant development, determines the timing of flowering and fruiting, and has a formative effect.

Light conditions on our planet are extremely wide: from such highly lit areas as highlands, deserts, steppes, to twilight lighting in water depths and caves.

The reaction of organisms to the daily rhythm of lighting, expressed in changes in the processes of trust and development, is called photoperiodism. The regularity and constant repeatability of this phenomenon from year to year allowed organisms in the course of evolution to coordinate their most important life processes with the rhythm of these time intervals. Under photoperiodic control Almost all metabolic processes associated with the growth, development, vital activity and reproduction of plants and animals are located.

The photoperiodic reaction is characteristic of both plants and and animals.

Seasonal rhythm in animals is most clearly manifested in the change of plumage in birds and fur in mammals, the frequency of reproduction and migration, hibernation of some animals, etc.

Biological rhythms are also characteristic of humans. Circadian rhythms are expressed in the alternation of sleep and wakefulness, fluctuations in body temperature within 0.7-0.8 ° C (at dawn it decreases, by noon it rises, in the evening it reaches a maximum, and then decreases again, especially quickly after a person falls asleep ), cycles of activity of the heart and kidneys, etc.

Living organisms are able to navigate in time, i.e. they have a biological clock. In other words, many organisms are characterized by the ability to sense daily, tidal, lunar and annual cycles, which allows them to prepare in advance for upcoming environmental changes.

Temperature limits of life. The need for heat for the existence of organisms is primarily due to the fact that all life processes are possible only against a certain thermal background, determined by the amount of heat and the duration of its action. The temperature of organisms and, as a consequence, the speed and nature of all processes depends on the ambient temperature. chemical reactions components of metabolism.

The boundaries of the existence of life are temperature conditions under which denaturation of proteins, irreversible changes in the colloidal properties of the cytoplasm, disruption of enzyme activity, and respiration do not occur. For most organisms this temperature range is from 0 to +500. However, a number of organisms have specialized enzyme systems and are adapted to active existence at temperatures beyond these limits.

Species whose optimal living conditions are confined to the region of high temperatures are classified as ecological group of thermophiles(bacteria inhabiting the thermal springs of Kamchatka with a water temperature of 85-93 ° C, several types of green algae, crustose lichens, seeds of desert plants located in the upper hot layer of soil. The temperature limit of representatives of the animal world usually does not exceed +55-58 ° C ( testate amoebas, nematodes, mites, some crustaceans, larvae of many dipterans).

Plants and animals that remain active at temperatures from 0 to -8°C. refer to ecological group of cryophiles(Greek Kryos - cold, ice). Cryophilia is characteristic of many bacteria, fungi, lichens, arthropods and other creatures living in the tundra, Arctic and Antarctic deserts, high mountains, cold polar waters, etc.

Representatives of most species of living organisms do not have the ability to actively thermoregulate their bodies. Their activity depends, first of all, on the heat coming from outside, and their body temperature depends on the ambient temperature. Such organisms are called poikilothermic (ectothermic). Poikilothermy is characteristic of all microorganisms, plants, invertebrates and most chordates.

Only at birds and mammals heat generated during intensive metabolism serves as a fairly reliable source of increasing body temperature and maintaining it at a constant level regardless of ambient temperature. This is facilitated by good thermal insulation created by the coat, dense plumage, and a thick layer of subcutaneous fatty tissue. Such organisms are called homoiothermic (endothermic, or warm-blooded). Endothermic property allows many species of animals (polar bears, pinnipeds, penguins, etc.) to conduct active lifestyle at low temperatures.

Special case homeothermy - heterothermy- characteristic of animals that hibernate or become temporarily torpid during unfavorable periods of the year (gophers, hedgehogs, the bats, Sony, etc.). Active they support high temperature body, and in the case low body activity - reduced, which is accompanied by a slowdown in metabolic processes and, as a consequence, low heat transfer.

The ecological role of oxen. Water is a necessary condition existence of all living organisms on Earth. The importance of water in life processes is determined by the fact that it is the main environment in the cell where metabolic processes take place and serves as the most important initial, intermediate or final product of biochemical reactions.

When studying the ecological role of water taken into account Not only quantity precipitation, But And the ratio of their size and evaporation. Areas in which evaporation exceeds annual precipitation are called arid(dry, arid). IN humid (moist) areas plants are provided with sufficient water.

Higher terrestrial plants leading an attached lifestyle, to a greater extent than animals, depend on the supply of substrate and air with moisture. There are three main groups of plants:

Hygrophytes- plants of excessively moist habitats with high air and soil humidity. The most typical hygrophytes are herbaceous plants and epiphytes of tropical rainforests and the lower layers of damp forests in different climatic zones. which are cultivated plants.

Xerophytes- plants of dry habitats that can tolerate prolonged drought while remaining physiologically active. These are plants of deserts, dry steppes, savannas, dry subtropics, sand dunes and dry, highly heated slopes.

The group of xerophytes includes succulents- plants with succulent, fleshy leaves or stems containing highly developed aquiferous tissue. There are leaf succulents (agaves, aloe, young, sedum) and stem ones, in which the leaves are reduced, and the above-ground parts are represented by fleshy stems (cacti, some milkweeds, slipways, etc.).

Succulents are confined mainly to the arid zones of Central America, South Africa, and the Mediterranean.

Mesophytes occupy an intermediate position between hygrophytes and xerophytes. They are common in moderately humid areas with moderately warm conditions and a fairly good supply of mineral nutrition. Mesophytes include plants of meadows, herbaceous forest cover, deciduous trees and shrubs from areas of moderately humid climates, as well as most cultivated plants and weeds. Mesophytes are characterized by high ecological plasticity, allowing them to adapt to changing environmental conditions.

Adaptation of animals to the water regime. The methods for regulating water balance in animals are more diverse than in plants. They can be divided into behavioral, morphological and physiological.

Among the behavioral adaptations include searching for bodies of water, choosing habitats, digging holes, etc. In holes, air humidity approaches 100%, which reduces evaporation through the integument and saves moisture in the body.

Towards morphological methods of maintaining normal water balance include formations that promote water retention in the body; these are the shells of terrestrial mollusks, the absence of skin glands and keratinization of the integument of reptiles, the chitinized cuticle of insects, etc.

Physiological adaptations for the regulation of water metabolism can be divided into three groups:

1) the ability of a number of species to form metabolic water and be satisfied with moisture supplied with food (many insects, small desert rodents);

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 characteristics. Important feature of man as an environmental factor lies in the 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 use part of the energy of organic substances formed by organisms of the previous trophic level. Humanity 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 limits to the growth of their numbers.[...]

The increase in population, energy supply, and technical equipment of people creates the prerequisites for populating any ecological niches. Humanity represents the only species on Earth with a worldwide distribution. This turns a person into an environmental factor with a global spread of influence.[...]

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

As a result of work, a person creates an artificial habitat around himself. Natural ecosystems are being replaced by anthropogenic ecosystems, in which humans are the absolutely dominant factor.[...]

As a result of human activity, changes occur in the physical environment - the gas composition of the air, the quality of water and food, 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 spent on artificial creation and maintenance optimal conditions environment.[...]

Scale of interaction modern society are not determined by nature biological needs man, but by the continuously increasing level of technical and social development. Human technical power has reached a scale commensurate with biosphere processes. For example, construction and mining equipment annually move more material onto the Earth's surface than is carried out to sea by all the world's rivers as a result of water erosion. Human activity on the planet changes the climate and affects the composition of the atmosphere and the World Ocean.[...]

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. Defining the current stage in the development of the biosphere and human society, we can say that technological and anthropogenic processes are playing an increasingly important role.[...]

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

Without filling the belly with food,

The twentieth century is chewing itself

And he chops, chops down the tree of life,

Like a merciless woodcutter...

Great mind! Forbid it

Cut at least the last branch.

Many types of human activities can be considered special environmental factors, which are called anthropogenic; the scale of action of anthropogenic factors becomes comparable with the action of geological forces; The biosphere responds to the impact of anthropogenic factors by reducing the number of species, depleting 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 human ones. 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 forests being replaced by open spaces. Living organisms that previously lived in forest thickets and switched to living in open spaces under the influence of environmental factors acquired new properties and characteristics: construction activity developed (voles, gerbils); a nomadic way of life, migration arose, the size of the herd increased (in the herd of forest animals, elk, there are only 20-30 heads, and the inhabitants of open spaces, deer, gather in herds of thousands). The nocturnal lifestyle was replaced by a daytime lifestyle, hierarchical connections in the herd became more complex, and guard functions began to be performed alternately by each member. It is believed that human ancestors - forest animals - found themselves in difficult circumstances in the new conditions. 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 means of attack and defense; slow movement speed compared to most four-legged animals 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, of signs of the human race - upright walking, increased complexity of tool activity, improvement of the structure of the hand, and increased complexity of nervous activity. From a geological point of view, this happened quite recently.

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

The earliest immediate predecessors or even representatives of the most ancient people - australopithecines - already had relatively flat faces, the brow ridges protruded forward, and a significant part of the face was occupied by a powerful lower jaw. They lived in open spaces and had a complex hierarchy. It was among Australopithecus that tool activity arose as a form of biological adaptation and as a new stage of 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 traits of human society, and the prehumans began to acquire the traits of people. Various methods of communication arose, daytime activity developed, and man began to use fire.

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

The Neanderthal had already built a dwelling - huts for 10-12 people, and 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 food harvesting, which led to changes in ecosystems.

8.5 thousand years ago the first metal smelting was done (Catal Huyuk, Southern Turkey). The development of crafts and then industry began.

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, art, and book printing.

Man 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 influence on nature).

2. Human activity has acquired a global character and has become a special, super-powerful environmental factor in the existence of living things in the biosphere.

Humans are reducing the areas 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 annually under the concrete of highways, settlements, and airports being built.

People consume sushi products, reducing the share of natural consumers.

The biomass of humanity 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's plant production.

Man is depleting energy reserves accumulated in the “dead ends” of the biosphere.

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

Man uses the Earth's resources and pollutes the biosphere: he extracts about 100 billion tons of ore, fossil fuels and other raw materials, which is 25 tons for every inhabitant of the planet. 96¸98% of extracted raw materials go to waste. Per inhabitant major cities accounts for 1 ton of waste (food and household). 6 billion tons per year of solid waste thrown into the oceans. Every year, 69-90 million tons of oil and petroleum 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.

Physical pollution of the biosphere is increasing - noise, heat, light, radioactive. The dustiness of the air environment is increasing.

3. The impact of anthropogenic factors causes reactions of biological systems.

a) Death of individuals and reduction in population numbers.

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

Millions of migratory birds are burned in gas flares that burn waste gases from oil production. Animals die in oil spills, on wires and power line supports (steppe eagles, gravediggers, golden eagles, short-eared eagle, etc.), when 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 individuals. Sulfur dioxide and sulfuric acid formed from sulfur dioxide, together with other substances, enter the soil and reduce its fertility. The acidity of the soil changes, which suppresses the activity of bacteria and reduces the number of earthworms. The most dangerous pollutant is oil.

Pollutants affect embryos and developing embryos, poisoning them, causing deformity and abnormalities in the development of the body, dysfunction of the gonads and organs, dysfunction of the nervous system.

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

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

c) Disturbance of population phenomena.

The structure of the population changes - 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 environmental pollution, reproduction cycles are disrupted (asynchronous development of germ cells in males and females), the number of pregnant females and the number of cubs in the litter decreases, and newborn mortality increases. The habitat of the species is disintegrating, habitat areas are being reduced, and small islands of habitat are being isolated.

d) Change in the ecosystem.

Reducing the number of species reduces ecosystem complexity; the loss of some species can lead to an outbreak of others; dominant species can be suppressed, and their place is taken by newly introduced 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 associated animal species, mainly invertebrates. Light, sound, and chemical pollution disrupt the established signaling systems in the natural community between species. As a result of changes in the structure of the community, its stability is disrupted, and massive outbreaks of numbers occur, usually of invertebrate animals. Thus, before our eyes, a gigantic depletion of the gene pool of the biosphere is taking place due to the extinction of species, a reduction in their population diversity and the number of individuals in all populations that are shrinking across the territory. Every day, from this number, one species of animal disappears irrevocably, and every week, one species of plant disappears. 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 destroyed over the next 20 years. Likewise, by the end of this century (at current rates of deforestation), the remaining area of ​​unlogged tropical forest will be reduced by half. During this period, the Earth's population is expected to increase by one and a half times - from just over 5 billion to almost 6 billion people.

It has become obvious that the balance of biosphere processes, disturbed by human economic activity, is being restored more slowly than ever before. The adaptation mechanisms of the biosphere are working “to the limit.” The gene pool of the biosphere is becoming depleted, creating the threat of unpredictable evolutionary consequences.

4. Many scientists characterize the current environmental situation as an “ecological 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.

Solving environmental problems - in particular, preserving the gene pool of the biosphere - is becoming increasingly urgent.

Humanity and every person, each of us must recognize the crisis situation and put forward ideas that will save life on the planet.