Autoecology or factorial ecology studies the totality of environmental factors acting on an isolated individual, and the individual's responses to their action.

environmental factors refers to any components of the environment that directly or indirectly affect living organisms. According to their characteristics, environmental factors are very diverse, have a different nature and specificity of action. They are divided into three groups: abiotic (factors of the inanimate environment), biotic (associated with the influence of living beings) and anthropogenic (associated with human activities).

Abiotic factors- this is a set of conditions of the inorganic environment, in any way affecting the organism and their communities. In ecology, they are considered as indispensable and important factors that ensure the life and development of plants, animals and microorganisms, they can affect organisms individually, simultaneously or interacting with each other. Abiotic factors include climatic, edaphic, topographic, hydrophysical and hydrochemical factors.

From climatic factors basic environmental significance have temperature, humidity and light, with the most important being the temperature factor. The intensity of metabolism of organisms and their geographical distribution depends on its value. Any organism is able to live within a certain temperature range. At the same time, the interval of optimal temperatures at which vital functions proceed most actively is relatively small. The temperature limits in which life processes proceed normally are called biokinetic temperatures. Their level is determined by many factors and primarily depends on the taxonomic position of a given species of plant or animal, which in turn is associated with the geographical place of origin of the species, certain conditions of its evolutionary development.

Of the climatic factors, the radiant energy of the Sun is also of great importance - the main source of life on the planet. The sun continuously radiates a huge amount of radiant energy, the power of which at the upper limit of the atmosphere is from 8.4 to 84 J/cm2 min (solar constant). As we approach the Earth's surface, much of the solar energy is trapped by the atmosphere and vegetation.

The environmental efficiency of radiant energy depends on the wavelength. Depending on the wavelength, within the entire light spectrum, there are visible light, ultraviolet and infrared parts.

Ultraviolet rays have a chemical effect on living organisms, infrared rays have a thermal effect. The following have the main ecological significance: photoperiodism - a regular change of light and dark times of the day; lighting intensity (in lux); voltage of direct and scattered radiation (in joules per unit surface and per unit time); chemical action of light energy.

The value of light - the visible part (0.35 - 0.75 microns) of the spectrum of radiant energy, as an environmental factor is associated with the possibility of photosynthesis of green plants and, ultimately, with the creation of organic matter, plant biomass, with the daily rhythm of organisms, etc.

Such environmental factors as wind, atmospheric pressure, smog, etc. also have a great influence on the biosphere in the aggregate and under the combined influence of temperature and radiant energy.

To edaphic factors refers to the totality of the physical and chemical properties of soils (structure, chemical composition, substances circulating in the soil - gas, water, organic and mineral elements, etc.). Edaphic factors determine the vital activity of organisms that live in the soil permanently or partially.

To hydrochemical and hydrophysical factors include all factors related to water. The role of water as an ecological factor is determined by its physical and chemical properties and mobility. Water is the habitat of various living organisms. The bodies of living organisms are mainly composed of water. Thus, the water content in plants ranges from 40 to 98%, in the body of animals - from 35 to 83%. Without water, metabolic processes cannot take place. Maintaining water balance is of great importance for all living organisms. Water can be in three states: vapor, liquid and solid, and this is of great importance in the life of plants and animals.

All living organisms, depending on their need for water, and, consequently, according to their habitats, are divided into a number of ecological groups: aquatic or hydrophilic (they live constantly in water), hygrophilic (they live in very humid habitats), mesophilic (they have moderate water needs). ) and xerophilous (living in dry habitats). Each of these groups is a good indicator of the environmental conditions prevailing in the area.

To biotic factors include the total amount of influences exerted on each other by living beings - bacteria, plants, animals. Biotic factors are not altered by organisms abiotic environmental conditions (humidity, temperature, etc.) and not the organisms themselves, but the relationship between organisms, direct effects of one of them on others, i.e. the nature of biotic factors is determined by the form of interconnections and relationships of living organisms. These relationships are extremely varied. They can develop on the basis of joint feeding, habitat and reproduction.

LECTURE №4

TOPIC: ENVIRONMENTAL FACTORS

PLAN:

1. The concept of environmental factors and their classification.

2. Abiotic factors.

2.1. Ecological role of the main abiotic factors.

2.2. topographic factors.

2.3. space factors.

3. Biotic factors.

4. Anthropogenic factors.

1. The concept of environmental factors and their classification

Ecological factor - any element of the environment that can directly or indirectly affect a living organism, at least at one of the stages of its individual development.

Environmental factors are diverse, and each factor is a combination of the corresponding environmental conditions and its resource (reserve in the environment).

Environmental environmental factors are usually divided into two groups: factors of inert (non-living) nature - abiotic or abiogenic; factors of living nature - biotic or biogenic.

Along with the above classification of environmental factors, there are many others (less common) that use other distinguishing features. So, there are factors that depend and do not depend on the number and density of organisms. For example, the effect of macroclimatic factors is not affected by the number of animals or plants, while epidemics (mass diseases) caused by pathogenic microorganisms depend on their number in a given area. Classifications are known in which all anthropogenic factors are classified as biotic.

2. Abiotic factors

In the abiotic part of the habitat (in inanimate nature), all factors, first of all, can be divided into physical and chemical. However, to understand the essence of the phenomena and processes under consideration, it is convenient to represent abiotic factors as a set of climatic, topographic, space factors, as well as characteristics of the composition of the environment (aquatic, terrestrial or soil), etc.

Physical factors are those whose source is physical state or a phenomenon (mechanical, wave, etc.). For example, the temperature, if it is high - there will be a burn, if it is very low - frostbite. Other factors can also affect the effect of temperature: in water - current, on land - wind and humidity, etc.

Chemical Factors are those that come from the chemical composition of the environment. For example, the salinity of the water, if it is high, life in the reservoir may be completely absent (Dead Sea), but at the same time, most cannot live in fresh water. marine organisms. The life of animals on land and in water depends on the adequacy of the oxygen content, etc.

Edaphic factors(soil) is a set of chemical, physical and mechanical properties of soils and rocks that affect both the organisms living in them, i.e. for which they are the habitat, and root system plants. The effects of chemical components (biogenic elements), temperature, humidity, and soil structure on the growth and development of plants are well known.

2.1. Ecological role of the main abiotic factors

solar radiation. Solar radiation is the main source of energy for the ecosystem. The energy of the Sun propagates in space in the form electromagnetic waves. For organisms, the wavelength of perceived radiation, its intensity and duration of exposure are important.

About 99% of all energy solar radiation make up rays with a wavelength k = nm, including 48% in the visible part of the spectrum (k = nm), 45% in the near infrared (k = nm) and about 7% in the ultraviolet (k< 400 нм).

Rays with X = nm are of primary importance for photosynthesis. Long-wave (far infrared) solar radiation (k > 4000 nm) has little effect on the vital processes of organisms. Ultraviolet rays with k\u003e 320 nm in small doses are necessary for animals and humans, since under their action vitamin D is formed in the body. Radiation with k< 290 нм губи­тельно для живого, но до поверхности Земли оно не доходит, поглощаясь озоновым слоем атмосферы.

As it passes through atmospheric air, sunlight is reflected, scattered, and absorbed. Pure snow reflects approximately 80-95% sunlight, polluted - 40-50%, chernozem soil - up to 5%, dry light soil - 35-45%, coniferous forests - 10-15%. However, illumination earth's surface varies significantly depending on the time of year and day, geographical latitude, slope exposure, atmospheric conditions, etc.

Due to the rotation of the Earth, daylight and darkness alternate periodically. Flowering, seed germination in plants, migration, hibernation, animal reproduction and much more in nature are associated with the duration of the photoperiod (day length). The need for light for plants determines their rapid growth in height, the layered structure of the forest. Aquatic plants spread mainly in the surface layers of water bodies.

Direct or diffuse solar radiation is not required only by a small group of living beings - some types of fungi, deep-sea fish, soil microorganisms, etc.

The most important physiological and biochemical processes carried out in a living organism, due to the presence of light, include the following:

1. Photosynthesis (1-2% of the solar energy falling on the Earth is used for photosynthesis);

2. Transpiration (about 75% - for transpiration, which provides cooling of plants and movement along them aqueous solutions minerals);

3. Photoperiodism (ensures the synchronism of life processes in living organisms to periodically changing environmental conditions);

4. Movement (phototropism in plants and phototaxis in animals and microorganisms);

5. Vision (one of the main analyzing functions of animals);

6. Other processes (synthesis of vitamin D in humans in the light, pigmentation, etc.).

The basis of the biocenoses of central Russia, like most terrestrial ecosystems, are producers. Their use of sunlight is limited by a number of natural factors and, first of all, by temperature conditions. In this regard, special adaptive reactions have been developed in the form of layering, mosaic leaves, phenological differences, etc. According to the requirements for lighting conditions, plants are divided into light or light-loving (sunflower, plantain, tomato, acacia, melon), shady or non-light-loving (forest herbs, mosses) and shade-tolerant (sorrel, heather, rhubarb, raspberries, blackberries).

Plants form the conditions for the existence of other types of living beings. That is why their reaction to lighting conditions is so important. Environmental pollution leads to a change in illumination: a decrease in the level of solar insolation, a decrease in the amount of photosynthetically active radiation (PAR - part of solar radiation with a wavelength of 380 to 710 nm), a change in the spectral composition of light. As a result, this destroys cenoses based on the arrival of solar radiation in certain parameters.

Temperature. For natural ecosystems In our zone, the temperature factor, along with light supply, is decisive for all life processes. The activity of populations depends on the time of year and time of day, since each of these periods has its own temperature conditions.

Temperature is mainly related to solar radiation, but in some cases is determined by the energy of geothermal sources.

At temperatures below the freezing point, a living cell is physically damaged by the resulting ice crystals and dies, and at high temperatures, denaturation of enzymes occurs. The vast majority of plants and animals cannot withstand negative body temperatures. The upper temperature limit of life rarely rises above 40–45 °C.

In the range between the extreme limits, the rate of enzymatic reactions (hence, the metabolic rate) doubles with every 10°C increase in temperature.

A significant part of organisms is able to control (maintain) body temperature, and primarily the most vital organs. Such organisms are called homeothermic- warm-blooded (from the Greek homoios - similar, therme - warmth), in contrast to poikilothermic- cold-blooded (from the Greek poikilos - various, changeable, diverse), having a variable temperature, depending on the ambient temperature.

Poikilothermic organisms in the cold season of the year or day reduce the level of vital processes up to anabiosis. This primarily concerns plants, microorganisms, fungi and poikilothermic (cold-blooded) animals. Only homoiothermic (warm-blooded) species remain active. Heterothermic organisms, being in an inactive state, have a body temperature not much higher than the temperature of the external environment; in the active state - quite high (bears, hedgehogs, bats, ground squirrels).

Thermoregulation of homoiothermic animals is provided by a special type of metabolism that goes with the release of heat in the body of animals, the presence of heat-insulating covers, size, physiology, etc.

As for plants, they have developed a number of properties in the process of evolution:

cold resistance– the ability to endure low positive temperatures for a long time (from 0°С to +5°С);

winter hardiness– the ability of perennial species to endure a complex of unfavorable winter conditions;

frost resistance- the ability to endure negative temperatures for a long time;

anabiosis- the ability to endure a period of prolonged lack of environmental factors in a state of a sharp decrease in metabolism;

heat resistance– the ability to endure high (over +38°…+40°С) temperatures without significant metabolic disorders;

ephemerality– reduction of ontogenesis (up to 2-6 months) in species growing under conditions of a short period of favorable temperature conditions.

In the aquatic environment, due to the high heat capacity of water, temperature changes are less abrupt and conditions are more stable than on land. It is known that in regions where the temperature varies greatly during the day, as well as in different seasons, the diversity of species is less than in regions with more constant daily and annual temperatures.

Temperature, like light intensity, depends on geographical latitude, season, time of day and slope exposure. Extreme temperatures (low and high) are exacerbated by strong winds.

The change in temperature as you rise in the air or dive into the aquatic environment is called temperature stratification. Usually, in both cases, a continuous decrease in temperature with a certain gradient is observed. However, there are other options as well. So, in summer, surface waters heat up more than deep ones. Due to a significant decrease in the density of water as it is heated, its circulation begins in the surface heated layer without mixing with the denser, colder water of the underlying layers. As a result, an intermediate zone with a sharp temperature gradient is formed between the warm and cold layers. All this affects the placement of living organisms in the water, as well as the transfer and dispersion of incoming impurities.

A similar phenomenon also occurs in the atmosphere, when the cooled layers of air move down and are located under the warm layers, i.e., there is a temperature inversion that contributes to the accumulation of pollutants in the surface air layer.

Inversions are facilitated by some features of the relief, such as pits and valleys. It occurs when there are substances at a certain height, such as aerosols, heated directly by direct solar radiation, which causes more intense heating of the upper air layers.

In the soil environment, daily and seasonal stability (fluctuations) of temperature depend on depth. A significant temperature gradient (as well as humidity) allows the inhabitants of the soil to provide themselves with a favorable environment with minor movements. The presence and abundance of living organisms can affect temperature. For example, under the canopy of a forest or under the leaves of an individual plant, there is a different temperature.

Precipitation, humidity. Water is essential for life on Earth, ecologically it is unique. Under almost the same geographical conditions on Earth, there are both a hot desert and a tropical forest. The difference is only in the annual amount of precipitation: in the first case, 0.2–200 mm, and in the second, 900–2000 mm.

Precipitation, closely related to air humidity, is the result of condensation and crystallization of water vapor in the high layers of the atmosphere. In the surface layer of air, dews and fogs form, and at low temperatures moisture crystallization is observed - frost falls.

One of the main physiological functions of any organism is to maintain an adequate level of water in the body. In the process of evolution, organisms have developed various adaptations for obtaining and economical use of water, as well as for experiencing a dry period. Some desert animals get water from food, others due to the oxidation of timely stored fats (for example, a camel, capable of biological oxidation from 100 g of fat to get 107 g of metabolic water); at the same time, they have a minimum water permeability of the outer integument of the body, and dryness is characterized by falling into a state of rest with a minimum metabolic rate.

Land plants obtain water mainly from the soil. Low rainfall, rapid drainage, intense evaporation, or a combination of these factors lead to desiccation, and excess moisture leads to waterlogging and waterlogging of soils.

The moisture balance depends on the difference between the amount of precipitation and the amount of water evaporated from the surfaces of plants and soil, as well as by transpiration]. In turn, evaporation processes directly depend on the relative humidity of the atmospheric air. At a humidity close to 100%, evaporation practically stops, and if the temperature further decreases, then the reverse process begins - condensation (fog forms, dew, frost fall).

In addition to the above, air humidity as an environmental factor at its extreme values ​​(high and low humidity) enhances the effect (aggravates) the effect of temperature on the body.

Saturation of air with water vapor rarely reaches its maximum value. Humidity deficit - the difference between the maximum possible and actually existing saturation at a given temperature. This is one of the most important environmental parameters, since it characterizes two quantities at once: temperature and humidity. The higher the moisture deficit, the drier and warmer, and vice versa.

Precipitation regime is the most important factor determining the migration of pollutants in the natural environment and their leaching from the atmosphere.

In relation to the water regime, the following ecological groups of living beings are distinguished:

hydrobionts- inhabitants of ecosystems, the entire life cycle of which takes place in water;

hygrophytes– plants of wet habitats (marsh marigold, European swimsuit, broad-leaved cattail);

hygrophiles- animals living in very damp parts of ecosystems (mollusks, amphibians, mosquitoes, wood lice);

mesophytes– plants of moderately humid habitats;

xerophytes– plants of dry habitats (feather grass, wormwood, astragalus);

xerophiles- inhabitants of arid territories that cannot tolerate high humidity (some species of reptiles, insects, desert rodents and mammals);

succulents- plants of the most arid habitats, capable of accumulating significant moisture reserves inside the stem or leaves (cacti, aloe, agave);

sclerophytes– plants of very arid territories, capable of withstanding severe dehydration (common camel's thorn, saxaul, saksagyz);

ephemera and ephemeroids- annual and perennial herbaceous species with a shortened cycle, coinciding with a period of sufficient moisture.

Water consumption of plants can be characterized by the following indicators:

drought tolerance– ability to tolerate reduced atmospheric and (or) soil drought;

moisture resistance- the ability to tolerate waterlogging;

transpiration rate- the amount of water spent on the formation of a unit of dry mass (for white cabbage 500-550, for pumpkin-800);

coefficient of total water consumption- the amount of water consumed by the plant and soil to create a unit of biomass (for meadow grasses - 350–400 m3 of water per ton of biomass).

Violation of the water regime, pollution of surface waters is dangerous, and in some cases fatal for cenoses. Changes in the water cycle in the biosphere can lead to unpredictable consequences for all living organisms.

The mobility of the environment. The causes of the movement of air masses (wind) are primarily uneven heating of the earth's surface, causing pressure drops, as well as the rotation of the Earth. The wind is directed towards warmer air.

Wind is the most important factor in the spread of moisture, seeds, spores, chemical impurities, etc. over long distances. It contributes both to a decrease in the near-Earth concentration of dust and gaseous substances near the place of their entry into the atmosphere, and to an increase in background concentrations in the air due to emissions from distant sources, including transboundary transport.

The wind accelerates transpiration (evaporation of moisture by the ground parts of plants), which especially worsens the conditions of existence at low humidity. In addition, it indirectly affects all living organisms on land, participating in the processes of weathering and erosion.

Mobility in space and mixing of water masses contribute to maintaining the relative homogeneity (homogeneity) of the physical and chemical characteristics of water bodies. average speed surface currents lies within 0.1-0.2 m/s, reaching in places 1 m/s, near the Gulf Stream - 3 m/s.

Pressure. Normal atmospheric pressure is considered to be the absolute pressure at the level of the World Ocean surface of 101.3 kPa, corresponding to 760 mm Hg. Art. or 1 atm. Within the globe there are constant areas of high and low atmospheric pressure, and at the same points seasonal and daily fluctuations are observed. As altitude increases above sea level, pressure decreases partial pressure oxygen, increases transpiration in plants.

Periodically, areas of low pressure are formed in the atmosphere with powerful air currents moving in a spiral towards the center, which are called cyclones. They are characterized by high rainfall and unstable weather. Opposite natural phenomena called anticyclones. They are characterized by stable weather, light winds and, in some cases, temperature inversion. During anticyclones, sometimes unfavorable meteorological conditions arise, which contribute to the accumulation of pollutants in the surface layer of the atmosphere.

There are also sea and continental atmospheric pressure.

The pressure in the aquatic environment increases as you dive. Due to the significantly (800 times) greater density of water than air, for every 10 m of depth in a freshwater reservoir, the pressure increases by 0.1 MPa (1 atm). The absolute pressure at the bottom of the Mariana Trench exceeds 110 MPa (1100 atm).

ionizingradiation. Ionizing radiation is the radiation that forms pairs of ions when passing through a substance; background - radiation created by natural sources. It has two main sources: cosmic radiation and radioactive isotopes, and elements in minerals. earth's crust that arose sometime in the process of formation of the Earth's substance. Due to the long half-life, the nuclei of many primordial radioactive elements have survived in the bowels of the Earth to this day. The most important of them are potassium-40, thorium-232, uranium-235 and uranium-238. Under the influence of cosmic radiation in the atmosphere, more and more new nuclei of radioactive atoms are constantly formed, the main of which are carbon-14 and tritium.

The radiation background of the landscape is one of the indispensable components of its climate. All known sources of ionizing radiation take part in the formation of the background, but the contribution of each of them to the total radiation dose depends on a specific geographical point. Man, as an inhabitant of the natural environment, receives the bulk of exposure from natural sources of radiation, and it is impossible to avoid this. All living things on Earth are exposed to radiation from the Cosmos. Mountain landscapes, due to their significant height above sea level, are characterized by an increased contribution of cosmic radiation. Glaciers, acting as an absorbing screen, retain in their mass the radiation of the underlying bedrock. Differences in the content of radioactive aerosols over the sea and land were found. The total radioactivity of sea air is hundreds and thousands of times less than that of continental air.

There are areas on the Earth where the exposure dose rate is ten times higher than the average values, for example, areas of uranium and thorium deposits. Such places are called uranium and thorium provinces. Stable and relatively more high level radiation is observed in places where granite rocks come out.

Biological processes accompanying the formation of soils significantly affect the accumulation of radioactive substances in the latter. With a low content of humic substances, their activity is weak, while chernozems have always been distinguished by a higher specific activity. It is especially high in chernozem and meadow soils located close to granite massifs. According to the degree of increase in the specific activity of the soil, it can be tentatively arranged in the following order: peat; chernozem; soils of the steppe zone and forest-steppe; soils developing on granites.

The effect of periodic fluctuations in the intensity of cosmic radiation near the earth's surface on the radiation dose of living organisms is practically insignificant.

In many regions of the globe, the exposure dose rate due to the radiation of uranium and thorium reaches the level of exposure that existed on Earth in a geologically observable time, at which the natural evolution of living organisms took place. In general, ionizing radiation has a more detrimental effect on highly developed and complex organisms, and a person is particularly sensitive. Some substances are evenly distributed throughout the body, such as carbon-14 or tritium, while others accumulate in certain organs. So, radium-224, -226, lead-210, polonium-210 accumulate in bone tissues. The inert gas radon-220 has a strong effect on the lungs, sometimes released not only from deposits in the lithosphere, but also from minerals mined by man and used as building materials. Radioactive substances can accumulate in water, soil, precipitation or air if the rate of their entry exceeds the rate radioactive decay. In living organisms, the accumulation of radioactive substances occurs when they are ingested with food.

2.2. Topographic factors

The influence of abiotic factors largely depends on the topographic characteristics of the area, which can greatly change both the climate and the features of soil development. The main topographic factor is the height above sea level. With altitude, average temperatures decrease, the daily temperature difference increases, the amount of precipitation, wind speed and radiation intensity increase, and pressure decreases. As a result, vertical zonality of vegetation distribution is observed in mountainous areas, corresponding to the sequence of changes in latitudinal zones from the equator to the poles.

Mountain ranges can serve as climatic barriers. Rising above the mountains, the air cools, which often causes precipitation and thus reduces its absolute moisture content. Getting then to the other side of the mountain range, the dried air helps to reduce the intensity of rain (snowfall), which creates a "rain shadow".

Mountains can play the role of an isolating factor in the processes of speciation, as they serve as a barrier to the migration of organisms.

An important topographical factor is exposition(illuminance) of the slope. In the Northern Hemisphere it is warmer on the southern slopes, while in the Southern Hemisphere it is warmer on the northern slopes.

Another important factor is slope steepness affecting drainage. Water flows down the slopes, washing away the soil, reducing its layer. In addition, under the influence of gravity, the soil slowly slides down, which leads to its accumulation at the base of the slopes. The presence of vegetation inhibits these processes, however, at slopes of more than 35°, soil and vegetation are usually absent and screes of loose material are created.

2.3. Space factors

Our planet is not isolated from the processes taking place in outer space. The Earth periodically collides with asteroids, approaches comets, cosmic dust, meteorite substances fall on it, various types of radiation from the Sun and stars. Cyclically (one of the cycles has a period of 11.4 years), solar activity changes.

Science has accumulated many facts confirming the influence of the Cosmos on the life of the Earth.

3. Biotic factors

All living things that surround an organism in a habitat constitute a biotic environment or biota. Biotic factors- is a set of influences of the vital activity of some organisms on others.

The relationships between animals, plants, and microorganisms are extremely diverse. First of all, distinguish homotypic reactions, i.e., the interaction of individuals of the same species, and heterotypic- relations between representatives of different species.

Representatives of each species are able to exist in such a biotic environment, where connections with other organisms provide them with normal living conditions. The main form of manifestation of these relationships is the nutritional relationships of organisms of various categories, which form the basis of food (trophic) chains, networks and the trophic structure of the biota.

In addition to food relations, spatial relationships also arise between plant and animal organisms. As a result of the action of many factors, diverse species are not united in an arbitrary combination, but only under the condition of adaptation to cohabitation.

Biotic factors manifest themselves in biotic relationships.

The following forms of biotic relationships are distinguished.

Symbiosis(cohabitation). This is a form of relationship in which both partners or one of them benefit from the other.

Cooperation. Cooperation is a long-term, inseparable mutually beneficial cohabitation of two or more species of organisms. For example, the relationship of a hermit crab and sea anemone.

Commensalism. Commensalism is an interaction between organisms, when the vital activity of one delivers food (freeloading) or shelter (lodging) to another. Typical examples are hyenas picking up the remains of half-eaten prey by lions, fish fry hiding under the umbrellas of large jellyfish, as well as some mushrooms growing at the roots of trees.

Mutualism. Mutualism is a mutually beneficial cohabitation, when the presence of a partner becomes a prerequisite for the existence of each of them. An example is the cohabitation of nodule bacteria and leguminous plants, which can live together on nitrogen-poor soils and enrich the soil with it.

Antibiosis. A form of relationship in which both partners or one of them are negatively affected is called antibiosis.

Competition. This is the negative impact of organisms on each other in the struggle for food, habitat and other conditions necessary for life. It manifests itself most clearly at the population level.

Predation. Predation is a relationship between a predator and a prey, which consists in eating one organism by another. Predators are animals or plants that catch and eat animals for food. So, for example, lions eat herbivorous ungulates, birds - insects, large fish - smaller ones. Predation is both beneficial to one organism and harmful to another.

At the same time, all these organisms need each other. In the process of interaction "predator - prey" occur natural selection and adaptive variability, that is, the most important evolutionary processes. Under natural conditions, no species tends (and cannot) lead to the destruction of another. Moreover, the disappearance of any natural "enemy" (predator) from the habitat can contribute to the extinction of its prey.

Neutralism. The mutual independence of different species living in the same territory is called neutralism. For example, squirrels and moose do not compete with each other, but drought in the forest affects both, although to different degrees.

Recently, more and more attention has been paid to anthropogenic factors- a set of human impacts on the environment, due to its urban-technogenic activities.

4. Anthropogenic factors

The current stage of human civilization reflects such a level of knowledge and capabilities of mankind that its impact on the environment, including biological systems, acquires the character of a global planetary force, which we single out into a special category of factors - anthropogenic, i.e. generated by human activity. These include:

Changes in the Earth's climate as a result of natural geological processes, enhanced by the greenhouse effect caused by changes in the optical properties of the atmosphere by emissions of mainly CO, CO2, and other gases into it;

Debris in near-Earth space (NES), the consequences of which have not yet been fully understood, except for the real danger to spacecraft, including communication satellites, locations of the earth's surface, and others that are widely used in modern systems of interaction between people, states and governments;

Reducing the power of the stratospheric ozone screen with the formation of the so-called “ ozone holes”, reducing the protective capabilities of the atmosphere against the entry of hard short-wave ultraviolet radiation dangerous for living organisms to the Earth's surface;

Chemical pollution of the atmosphere with substances that contribute to the formation of acid precipitation, photochemical smog and other compounds that are dangerous for biospheric objects, including humans and artificial objects created by them;

Pollution of the ocean and changes in the properties of ocean waters due to oil products, their saturation with carbon dioxide of the atmosphere, which in turn is polluted by vehicles and thermal power plants, burial of highly toxic chemical and radioactive substances in ocean waters, pollution from river runoff, disturbances in the water balance of coastal areas due to regulation rivers;

Depletion and pollution of all kinds of springs and land waters;

Radioactive contamination of individual sites and regions with a tendency to spread over the Earth's surface;

Soil pollution due to polluted precipitation (eg acid rain), suboptimal use of pesticides and mineral fertilizers;

Changes in the geochemistry of landscapes, in connection with thermal power engineering, the redistribution of elements between the bowels and the surface of the Earth as a result of mining and metallurgical redistribution (for example, the concentration heavy metals) or extraction to the surface of anomalous in composition, highly mineralized groundwater and brines;

Continued accumulation on the surface of the Earth of household garbage and all kinds of solid and liquid waste;

Violation of the global and regional ecological balance, the ratio of ecological components in the coastal part of the land and the sea;

The ongoing, and in some places - increasing desertification of the planet, the deepening of the process of desertification;

Reducing the area of ​​tropical forests and northern taiga, these main sources of maintaining the oxygen balance of the planet;

Release as a result of all the above processes of ecological niches and filling them with other species;

Absolute overpopulation of the Earth and relative demographic overpopulation of certain regions, extreme differentiation of poverty and wealth;

Deterioration of the living environment in overcrowded cities and metropolitan areas;

The exhaustion of many mineral deposits and the gradual transition from rich to ever poorer ores;

Strengthening social instability as a result of the increasing differentiation of the rich and poor part of the population of many countries, the increase in the level of armament of their population, criminalization, natural environmental disasters.

Decrease in the immune status and health status of the population of many countries of the world, including Russia, repeated repetition of epidemics, which are becoming more massive and severe in their consequences.

This is by no means a complete circle of problems, in solving each of which a specialist can find his place and work.

The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it.

The physical factor as a pollutant of human activity is an unacceptable level of thermal pollution (especially radioactive).

Biological pollution of the environment is a variety of microorganisms, the most dangerous among which are various diseases.

Control questions and tasks

1. What are environmental factors?

2. What environmental factors are classified as abiotic, which are biotic?

3. What is the name of the totality of the influences of the life activity of some organisms on the life activity of others?

4. What are the resources of living beings, how are they classified and what is their ecological significance?

5. What factors should be taken into account in the first place when creating ecosystem management projects. Why?

Question 2. What effect does temperature have on different types of organisms?
Any kind of organisms is able to live only within a certain temperature range, within which the temperature conditions are most favorable for its existence, and its vital functions are carried out most actively. Temperature directly affects the rate of biochemical reactions in the bodies of living organisms, which proceed within certain limits. The temperature limits in which organisms usually live are from 0 to 50oC. But some bacteria and algae can live in hot springs at a temperature of 85-87°C. High temperatures (up to 80oC) are tolerated by some unicellular soil algae, scale lichens, and plant seeds. There are animals and plants that can withstand the effects of very low temperatures - until they freeze completely. As we approach the boundaries of the temperature interval, the speed of life processes slows down, and beyond its limits they stop altogether - the organism dies.
Most animals are cold-blooded (poikilothermic) organisms - their body temperature depends on the ambient temperature. These are all types of invertebrates and a significant part of vertebrates (fish, amphibians, reptiles).
Birds and mammals are warm-blooded (homeothermic) animals. Their body temperature is relatively constant and largely dependent on the metabolism of the organism itself. Also, these animals develop adaptations that allow them to retain body heat (hair, dense plumage, a thick layer of subcutaneous adipose tissue, etc.).
In most of the Earth's territory, temperature has clearly defined daily and seasonal fluctuations, which determines certain biological rhythms of organisms. The temperature factor also affects the vertical zonality of fauna and flora.

Question 3. How do animals and plants get the water they need?
Water- the main component of the cytoplasm of cells, is one of the most important factors affecting the distribution of terrestrial living organisms. Lack of water leads to a number of adaptations in plants and animals.
Plants use their roots to extract the water they need from the soil. Drought-resistant plants have a deep root system, smaller cells, and an increased concentration of cell sap. Water evaporation decreases as a result of leaf reduction, the formation of a thick cuticle or wax coating, etc. Many plants can absorb moisture from the air (lichens, epiphytes, cacti). A number of plants have a very short growing season (as long as there is moisture in the soil) - tulips, feather grass, etc. In dry times, they are dormant in the form of underground shoots - bulbs or rhizomes.
All terrestrial animals need a periodic supply to compensate for the inevitable loss of water due to evaporation or excretion. Many of them drink water, others, such as amphibians, some insects and mites, suck it up through the integument of the body in a liquid or vapor state. In terrestrial arthropods, dense covers are formed that prevent evaporation, metabolism is modified - insoluble products (uric acid, guanine) are released. Many inhabitants of deserts and steppes (turtles, snakes) hibernate during the drought period. A number of animals (insects, camels) use metabolic water for life, which is produced during the breakdown of fat. Many animal species make up for the lack of water by absorbing it when drinking or with food (amphibians, birds, mammals).

Question 4. How do organisms react to different illumination?
sunlight- the main source of energy for living organisms. The intensity of light (illuminance) for many organisms is a signal for the restructuring of the processes occurring in the body, which allows them to the best way respond to ongoing changes external conditions. Light is especially important for green plants. The biological effect of sunlight depends on its characteristics: spectral composition, intensity, daily and seasonal periodicity.
In many animals, light conditions cause a positive or negative reaction to light. Some insects (moths) flock to the light, others (cockroaches) avoid it. The change of day and night is of the greatest ecological importance. Many animals are exclusively diurnal (most birds), others are exclusively nocturnal (many small rodents, bats, etc.). Small crustaceans hovering in the water column stay at night in surface waters, and during the day they sink to the depths, avoiding too bright light.
The ultraviolet part of the spectrum has a high photochemical activity: in the animal body it is involved in the synthesis of vitamin D, these rays are perceived by the organs of vision of insects.
The visible part of the spectrum (red and blue rays) provides the process of photosynthesis, the bright color of flowers (attracting pollinators). In animals, visible light is involved in spatial orientation.
Infrared rays are a source of thermal energy. Heat is important for thermoregulation of cold-blooded animals (invertebrates and lower vertebrates). In plants, infrared radiation affects the enhancement of transpiration, which contributes to the absorption carbon dioxide and the movement of water through the body of the plant.
Plants and animals respond to the ratio between the duration of the period of light and darkness during the day or season. This phenomenon is called photoperiodism. Photoperiodism regulates the daily and seasonal rhythms of the vital activity of organisms, and also represents climatic factor, which determines the life cycles of many species. In plants, photoperiodism is manifested in the synchronization of the period of flowering and fruit ripening with the period of the most active photosynthesis; in animals - in the coincidence of the breeding season with an abundance of food, in bird migrations, a change in coat in mammals, falling into hibernation, changes in behavior, etc.

Question 5. How do pollutants act on organisms?
As a result economic activity human environment is polluted by by-products of production. Such pollutants include: hydrogen sulfide, sulfur dioxide, salts of heavy metals (copper, lead, zinc, etc.), radionuclides, by-products of oil refining, etc. Especially in areas with developed industry, these substances can cause the death of organisms and stimulate the development of the mutation process, which can eventually lead to an ecological disaster. Harmful substances found in water bodies, in the soil and in the atmosphere adversely affect plants, animals and humans.
Many pollutants act as poisons, causing entire plant or animal species to become extinct. Others can be passed along food chains, accumulate in the bodies of organisms, cause gene mutations, the significance of which can only be assessed in the future. Human life also becomes impossible in conditions of environmental pollution, because there are numerous direct poisonings with poisons, as well as side effects of a polluted environment (increase in infectious diseases, cancers and diseases of various organ systems). As a rule, pollution of nature leads to a decrease in species diversity and a violation of the stability of biocenoses.

Ecological factors - a set of certain environmental conditions and its elements that can affect organisms interacting with this environment. Each organism, in turn, reacts appropriately to these influences and develops adaptive measures. It is environmental factors that determine the possibility of the existence and normal functioning of organisms. However, most often living beings are exposed to not one, but several factors at the same time. This undoubtedly has a specific effect on the ability to adapt.

Classification

According to their origin, the following environmental factors are distinguished:

1. Biotic.

2. Abiotic.

3. Anthropogenic.

The first group consists of the relationships of various living organisms with each other, and also includes their general impact on the environment. In addition, the interaction of living organisms can lead to a change in abiotic factors, for example, a change in the composition of soil covers, as well as microclimatic conditions of the environment. There are two groups of biotic factors: zoo- and phytogenic. The former are responsible for the impact of different animal species on each other and on the world, the latter, in turn, for the effect of plant organisms on the environment and their interaction with each other. It should be noted that the impact of animals or plants within one specific species is also significant and is studied along with interspecific relationships.

The second group includes environmental factors that illustrate the interaction of inanimate nature and living organisms, carried out through direct or indirect influence. There are chemical, climatic, hydrographic, pyrogenic, orographic and edaphic factors. They reflect the effects of all four elements: water, earth, fire and air. The third group of factors shows the level of impact of human life processes on the environment, as well as flora and fauna. This category includes direct and indirect impact, which is in any form of life activity. human society. For example, the development of land covers, the creation of new species and the destruction of existing ones, the adjustment of the number of individuals, environmental pollution, and much more.

Biosystem

From the totality of conditions and factors, as well as the species present in a particular region, a biosystem is formed. It clearly illustrates all the relationships between organisms and elements of inanimate nature. The structure of a biosystem can be complex and intricate, so in some cases it is more convenient to use a special form, which is called the "Ecological Pyramid". A similar graphic model was developed by the Englishman C. Elton in 1927. There are three types of pyramids, each of which reflects either the number of populations (pyramid of numbers), or total number biomass spent (pyramid of biomass), or the stock of energy contained in organisms (pyramid of energy).

Most often, the construction of such structures has a pyramidal shape, from where, in fact, the name came from. However, in some cases, you may encounter the so-called inverted pyramid. This means that the number of consumers exceeds the number of producers.

Environmental factors are an integral part of the existence of populations and the creation of living conditions. The study of each factor separately creates many additional factors that express the whole complex of its influence, action and significance in nature.

Classification of environmental factors

Systematization of the properties of the environment simplifies the perception, compilation and study of their parameters. The components of the environment are divided according to the nature and range of impact on the natural and anthropogenic environment. These include:

• Fast acting. The impact of the factor on the processes of energy and information metabolism for the implementation, which requires a minimum amount of time.
• Indirect. The impact of individual factors is limiting or concomitant for the development of processes, metabolism or changes in the material composition of an element, group of organisms or environmental substances.
• The selective impact is aimed at the components of the environment, characterizing them as limiting for a certain type of organisms or processes.

Certain types of animals eat only one type of food, their selective influence will be the habitat with this plant. The overall spectrum of impact is a factor that determines the impact of a complex of environmental conditions on different levels of life organization.

A variety of environmental factors allows them to be classified according to the signs of their action:

• by habitat;
• by time;
• by frequency;
• by the nature of the impact;
• by origin;
• by the object of influence.

Their classification has a multicomponent description and within each factor is divided into many independent ones. This makes it possible to describe in detail the environmental conditions and their combined influence at different levels of life organization.

Groups of environmental factors

The conditions for the existence of organisms, regardless of the level of its organization, are influenced by environmental factors, which are divided into groups according to their organization. There are three groups of factors: abiotic; biotic; anthropogenic.

Anthropogenic factors called the impact on the environment: products of human activity, change in the natural environment with replacement by artificially created objects. These factors complement pollution by residual products of industry, life (emissions, waste, fertilizers).

Abiotic environmental factors. The natural environment consists of components that make it up as a whole. It consists of factors that determine it as a habitat for different levels of life organization. Its components:

• Light. The attitude to light determines the habitat, the main processes of plant metabolism, the diversity of animals and their vital activity.
• Water. It is a component present in living organisms of all levels of organization of life on Earth. This habitat element occupies most of the Earth and is the habitat. A variety of living organisms in most of their species belongs to this environment.
• Atmosphere. The gaseous shell of the earth, in which the processes that regulate the climate and temperature regimes of the planet take place. These regimes determine the belts of the planet and the conditions of existence on them.
• Edaphic or soil factors. Soil is the result of erosion rocks The properties of the earth determine the appearance of the planet. The inorganic components included in its composition serve nutrient medium for plants.
• Terrain relief. The orographic conditions of the area are regulated by changes in the surface under the influence of the geological erosion processes of the earth. These include hills, hollows, river valleys, plateaus and other geographical boundaries of the Earth's surface.
• The influence of abiotic and biotic factors is interrelated. Each factor has a positive or negative effect on living organisms.

Biotic environmental factors. The relationship between organisms and their influence on objects of inanimate nature is called biotic environmental factors. These factors are classified according to the actions and relationships of organisms:

Type of interaction of individuals, their ratio and description

Action of environmental factors

Environmental factors have a complex effect on organisms. Their action is characterized by quantitative indicators expressed in the general flow of their influence. The ability to adapt to the action of environmental factors is called the ecological valence of the species. The threshold of influence is expressed by the zone of tolerance. A wide range of distribution and adaptability of the species characterizes it as a eurybiont, and a narrow range - wall-beaten.

The combined influence of factors is characterized by the ecological spectrum of the species. Patterns of influence of factors. The law of action of factors:

• Relativity. Each factor affects jointly and characterizes it: intensity, direction and quantity in a certain period of time.
• Optimality of factors - the average range of their impact is favorable.
• Relative substitutability and absolute irreplaceability Living conditions depend on irreplaceable abiotic environmental factors (water, light) and their absolute absence is irreplaceable for the species. The compensatory effect is exerted by an excess of other factors.

Influence of environmental factors

The influence of each factor is due to their characteristics. The main groups of these factors are:

• Abiotic. Light affects the physiological processes in the human body, the vital activity of animals and the vegetation of plants. Biotic. When the seasons change, the tree sheds its leaves and fertilizes the upper soil layer.
• Anthropogenic. Human activities since the Stone Age have had an impact on the environment. natural environment. With the development of industry and economic activity, its pollution is the main human impact on the environment.
• Ecofactors have a contiguous effect and it is difficult to describe their separate impact.

Environmental factors: examples

Examples of environmental factors are the basic conditions of existence at the population level. Main factors:

• Light. Plants use light for vegetative processes. Physiological processes under the influence of light in the human body are genetically determined in the process of evolution.
• Temperature. The biodiversity of organisms is expressed in the existence of species in different temperature ranges. Under the influence of temperature, metabolic processes in the body are carried out.
• Water. An element of the environment that influences the existence and adaptation of organisms. They also include air, wind, soil, man. These factors create dynamic processes in nature and exert their influence on the processes in it.

Environmental pollution is a paramount concern for ecological communities, environmental protection. Waste facts (anthropogenic environmental factors):

• AT pacific ocean discovered an island made of waste (plastic bottles and other substances). Plastic decomposes over 100 years, film - 200 years. Water can accelerate this process and this will become another factor in the pollution of the hydrosphere. Animals eat plastic, mistaking them for jellyfish. Plastic is not digested and the animal may die.
• Air pollution in China, India and other industrial cities poisons the body. Toxic waste from industrial plants comes from sewage into rivers and poison the waters, which, along the chain of water balance, can pollute the air masses, groundwater and are dangerous to humans.
• In Australia, the Society for the Protection of Animals and the Conservation of Biodiversity is stretching vines along the highway. This protects koalas from death.
• To protect the rhinoceros from extinction as a species, they cut off the horn.

Ecological factors are multifactorial conditions for the existence of each species at different levels of life organization. Each level of the organization uses them rationally and the way they are used is different.