The influence of the environment on the body.

Any organism is an open system, which means that it receives substance, energy, information from outside, and thus is completely dependent on the environment. This is reflected in the law, open to Russian scientists K.F. Steering: "the results of the development (changes) of any object (organism) are determined by the ratio of its internal features and the features of the environment in which it is located." Sometimes this law is called the first environmental law, because it is universal.

Organisms affect the environment by changing the gas composition of the atmosphere (H: as a result of photosynthesis), participate in the formation of soil, relief, climate, etc.

The limit of the impact of organisms on the habitat describes a different environmental law (Yu.N. Kurazhkovsky): each species of organisms, consuming the substances it needs from the environment and releasing the products of its vital activity into it, changes it in such a way that the habitat becomes unsuitable for its existence .

1.2.2. Ecological environmental factors and their classification.

Many individual elements of the environment that affect organisms at least at one of the stages of individual development are called environmental factors.

According to the nature of their origin, abiotic, biotic and anthropogenic factors are distinguished. (Slide 1)

Abiotic factors  - These are properties of inanimate nature (temperature, light, humidity, composition of air, water, soil, natural radiation background of the Earth, terrain), etc., which directly or indirectly affect living organisms.

Biotic factors  - these are all forms of the impact of living organisms on each other. The action of biotic factors can be both direct and indirect, expressed in changes in environmental conditions, for example, changes in soil composition under the influence of bacteria or changes in the microclimate in the forest.

Mutual relations between individual species of organisms underlie the existence of populations, biocenoses and the biosphere as a whole.

Previously, the effects of humans on living organisms were also classified as biotic factors, but at the present time they distinguish a special category of factors generated by man.

Anthropogenic factors- these are all forms of human activity that lead to a change in nature as a habitat and other species and directly affect their lives.

Human activities on the planet should be singled out in a special force that exerts on the nature of both direct and indirect effects. Direct effects include the consumption, reproduction and dispersal of human as individual species of animals and plants, and the creation of entire biocenoses. Indirect impact is carried out by changing the habitat of organisms: climate, river regime, state of the land, etc. As the population grows and the technical equipment of mankind grows, the share of anthropogenic environmental factors steadily increases.

Environmental factors are variable in time and space. Some environmental factors are considered relatively constant over long periods of time in the evolution of species. For example, the force of solar radiation, the salt composition of the ocean. Most environmental factors — air temperature, humidity, and air velocity — are very variable in space and time.

In accordance with this, depending on the regularity of exposure, environmental factors are divided into (Slide 2):

· regular periodic that change the strength of the effect due to the time of day, the season of the year, or the rhythm of the tides in the ocean. For example: a decrease in temperature in the temperate climate zone of northern latitude with the onset of the winter of the year, etc.

· irregularly periodic , catastrophic phenomena: storms, rain, floods, etc.

· non-periodic, arising spontaneously, without a clear pattern, one-time. For example, the emergence of a new volcano, fires, human activity.

Thus, every living organism is influenced by the inanimate nature of other species, including humans, and, in turn, affects each of these components.

By priority factors are divided into primary   and secondary .

Primary  environmental factors existed on the planet always, even before the appearance of living beings, and all living things adapted to these factors (temperature, pressure, tides, seasonal and daily frequency).

Secondary  environmental factors arise and change due to the variability of primary environmental factors (turbidity of water, air humidity, etc.).

According to the action on the body, all factors are divided into direct action factors   and indirect .

According to the degree of impact they are divided into lethal (leading to death), extreme, limiting, disturbing, mutagenic, teratogenic, leading to deformities in the course of individual development).

Each environmental factor is characterized by certain quantitative indicators: strength, pressure, frequency, intensity, etc.

1.2.3. Patterns of environmental factors on organisms. Limiting factor. The law of minimum Liebig. The law of tolerance Shelford. The doctrine of ecological optima species. The interaction of environmental factors.

Despite the diversity of environmental factors and the different nature of their origin, there are some general rules and patterns of their impact on living organisms. Any environmental factor can affect the body as follows (Slide):

· Change the geographic distribution of species;

· Change the fecundity and mortality of species;

· Cause migration;

· Promote the appearance of adaptive qualities and adaptations in species.

The effect of the factor is most effective at a certain value of the factor that is optimal for the organism, and not at its critical values. Consider the patterns of action of the factor on organisms. (Slide).

The dependence of the result of the environmental factor on its intensity is a favorable range of the environmental factor is called optimum zone   (normal life). The more significant the deviation of the factor from the optimum, the more this factor inhibits the vital activity of the population. This range is called zone of oppression (pessimum) . The maximum and minimum tolerable values ​​of the factor are critical points beyond which the existence of an organism or population is no longer possible. The range of the factor between critical points is called tolerance zone   (endurance) of the body in relation to this factor. The point on the x-axis, which corresponds to the best indicator of the life of the organism, means the optimal value of the factor and is called the optimum point.   Since it is difficult to determine the optimum point, we usually talk about optimum zone   or comfort zone. Thus, the points of minimum, maximum and optimum are three cardinal points which determine the possible reactions of the body to this factor. The environmental conditions in which a factor (or a combination of factors) goes beyond the comfort zone and has a depressing effect are called in ecology extreme .

These patterns are called "Optimum rule" .

For the life of organisms need a certain combination of conditions. If all environmental conditions are favorable, with the exception of one, then this condition becomes decisive for the life of the organism in question. It limits (limits) the development of the organism, therefore it is called limiting factor . So The limiting factor is the ecological factor, the value of which goes beyond the limits of the survival rate of a species.

For example, the winter fish in the water bodies are caused by a lack of oxygen, carps do not live in the ocean (salt water), and the migration of soil worms causes an excess of moisture and a lack of oxygen.

Initially, it was found that the development of living organisms limits the lack of any component, for example, mineral salts, moisture, light, etc. In the middle of the XIX century, the German organic chemist Eustace Liebig was the first to experimentally proved that plant growth depends on the nutritional element that is present in relatively minimal quantities. He called this phenomenon the law of the minimum; in honor of the author it is also called liebig's law . (Liebig's barrel).

In modern wording minimum law   It sounds like this: the body's endurance is determined by the weakest link in the chain of its ecological needs. However, as it turned out later, not only a shortage, but also an excess of a factor, for example, the death of a crop due to rains, oversaturation of soil with fertilizers, etc., can be limiting. The notion that along with the minimum the limiting factor may be the maximum, entered 70 years after Liebig, the American zoologist V. Shelford, who formulated law of tolerance . According to the law of tolerance the limiting factor of population (organism) prosperity can be at a minimum or maximum environmental impact, and the range between them determines the amount of endurance (tolerance limit) or ecological valence of an organism to a given factor

The principle of limiting factors is valid for all types of living organisms - plants, animals, microorganisms and applies to both abiotic and biotic factors.

For example, a limiting factor for the development of organisms of a given species may be competition from another species. In agriculture, pests and weeds often become the limiting factor, and for some plants the lack (or absence) of representatives of another species becomes the limiting factor of development. For example, a new species of fig was brought from the Mediterranean to California, but it did not bear fruit until the only species of pollinator for it was brought from there.

In accordance with the law of tolerance, any excess substance or energy turns out to be the beginning of a polluting environment.

Thus, an excess of water, even in dry areas, is harmful and water can be considered as a normal pollutant, although it is simply necessary in optimal quantities. In particular, excess water prevents normal soil formation in the chernozem zone.

The wide ecological valency of the species in relation to abiotic environmental factors is designated by adding to the name of the factor the prefix “Heury”, a narrow “wall”. Species for which existence strictly certain ecological conditions are necessary, name stenobiont and species that adapt to the ecological situation with a wide range of parameters, - evribiontnymi .

For example, animals that can tolerate significant fluctuations in temperature are called eurythermal, narrow temperature range characteristic of stenothermic organisms. (Slide). Small changes in temperature have little effect on eurythermal organisms and can be fatal for stenothermic (Fig. 4). Eurygidroid   and stenohydroid   organisms differ in response to moisture fluctuations. Euryhaline   and stenogalinnye - have a different reaction to the degree of salinity of the environment. Evrioiknye   organisms are able to live in different places, and wall stencils   - exhibit stringent requirements for the choice of habitat.

In relation to pressure, all organisms are divided into eribatnye   and stenokatnye   or stopping   (deep-sea fish).

In relation to oxygen emit euryoxybionts   (crucian carp) and stenoxybiont s (grayling).

In relation to the territory (biotope) - eurytopic   (big tit) and stenotopic   (osprey).

In relation to food - erifagi   (corvids) and stenophagi among which can be distinguished ichthyophage   (osprey), entomophages   (carnivore, swift, swallow), herpetophagous   (Bird - secretary).

Ecological valences of a species in relation to different factors can be very diverse, which creates a variety of adaptations in nature. The set of environmental valences in relation to various environmental factors is ecological spectrum of the species .

The limit of tolerance of an organism changes during the transition from one stage of development to another. Often young organisms are more vulnerable and more demanding to environmental conditions than adults.

The most critical in terms of the impact of various factors is the reproduction period: during this period many factors become limiting. Ecological valence for breeding individuals, seeds, embryos, larvae, eggs is usually narrower than for adult non-breeding plants or animals of the same species.

For example, many marine animals can carry brackish or fresh water with a high chloride content, so they often enter rivers upstream. But their larvae cannot live in such waters, so the species cannot breed in the river and does not settle here for a permanent habitat. Many birds fly to breed chicks to places with warmer climates, etc.

So far it has been a question of the limit of tolerance of a living organism in relation to one factor, but in nature all environmental factors act together.

The optimal zone and limits of endurance of the organism in relation to any environmental factor can shift, depending on the combination in which other factors act simultaneously. This pattern is called interaction of environmental factors (constellation ).

For example, it is known that heat is easier to tolerate in dry, rather than humid, air; the risk of freezing is much higher at low temperatures with strong winds than in calm weather. For plant growth is required, in particular, an element such as zinc, it is he who often turns out to be the limiting factor. But for plants growing in the shade, the need for it is less than for those in the sun. There is a so-called compensation factors.

However, mutual compensation has certain limits and one of the factors cannot be completely replaced by another. The complete absence of water or at least one of the necessary elements of mineral nutrition makes plant life impossible, despite the most favorable combinations of other conditions. Hence the conclusion that all environmental conditions necessary for the maintenance of life play an equal role and any factor can limit the possibility of the existence of organisms - this is the law of equivalence of all living conditions.

It is known that each factor influences different functions of an organism in different ways. Conditions that are optimal for some processes, for example, for the growth of an organism, can be a zone of oppression for others, for example, for reproduction, and go beyond the limits of tolerance, that is, lead to death, for others. Therefore, the life cycle, according to which the body at certain periods primarily performs certain functions — nutrition, growth, reproduction, resettlement — is always coordinated with seasonal changes in environmental factors, such as seasonality in the plant world, due to the change of seasons.

Among the laws that determine the interaction of an individual or individual with his environment, we highlight environmental compliance rule . It claims that the species of organisms can exist so far and so far as the surrounding natural environment corresponds to the genetic possibilities of adapting this species to its fluctuations and changes. Each species of living originated in a certain environment, to some extent adapted to it, and the further existence of the species is possible only in a given environment or close to it. An abrupt and rapid change in the living environment can lead to the fact that the genetic capabilities of a species will not be sufficient to adapt to new conditions. On this, in particular, one of the hypotheses of extinction of large reptiles with a sharp change in abiotic conditions on the planet is based: large organisms are less variable than small ones, therefore, they need much more time to adapt. In this regard, the radical transformation of nature is dangerous for the currently existing species, including for the person himself.

1.2.4. Adaptation of organisms to adverse environmental conditions

Environmental factors can act as:

· irritants   and induce adaptive changes in physiological and biochemical functions;

· limiters , causing the impossibility of existence in these conditions;

· modifiers causing anatomical and morphological changes in organisms;

· signals , indicating changes in other environmental factors.

In the process of adapting to adverse environmental conditions, organisms were able to develop three main ways of avoiding the latter.

Active path  - contributes to the enhancement of resilience, the development of regulatory processes that allow to carry out all the vital functions of organisms, despite adverse factors.

For example, warm-bloodedness in mammals and birds.

Passive way  associated with the subordination of the vital functions of the body to change environmental factors. For example, the phenomenon hidden life , accompanied by the suspension of life during the drying of the reservoir, cooling, etc., up to the state imaginary death   or anabiosis .

For example, dried plant seeds, their spores, as well as small animals (rotifers, nematodes) are able to withstand temperatures below 200 o C. Examples of anabiosis? Winter dormancy of plants, hibernation of vertebrates, the preservation of seeds and spores in the soil.

The phenomenon in which there is a temporary physiological rest in the individual development of some living organisms, due to adverse environmental factors, is called diapause .

Avoiding adverse effects  - development by the body of such life cycles in which the most vulnerable stages of its development are completed in the most favorable periods of the year in terms of temperature and other conditions.

The usual path of such devices is migration.

Evolutionary adaptations of organisms to environmental conditions, expressed in changes in their external and internal features, are called adaptations . There are various types of adaptations.

Morphological adaptations. Organisms have such features of the external structure, which contribute to the survival and successful functioning of organisms in their usual conditions.

For example, a streamlined body shape in aquatic animals, the structure of succulents, adaptations of halophytes.

The morphological type of adaptation of an animal or plant, in which they have an external form reflecting the way they interact with the environment, is called life form . In the process of adapting to the same environmental conditions, different species may have a similar life form.

For example, whale, dolphin, shark, penguin.

Physiological adaptations  manifested in the characteristics of the enzymatic set in the digestive tract of animals, determined by the composition of food.

For example, the provision of moisture due to the oxidation of fat in camels.

Behavioral adaptations  - manifested in the creation of shelters, movement in order to select the most favorable conditions, scaring predators, hiding, gregarious behavior, etc.

Adaptations of each organism are determined by its genetic predisposition. The rule of compliance of environmental conditions of genetic predetermination   says: as long as the environment surrounding a certain type of organism corresponds to the genetic possibilities of adaptation of this species to its fluctuations and changes, this species may exist. An abrupt and rapid change in habitat conditions can lead to the fact that the rate of adaptive reactions will lag behind the change in environmental conditions, which will lead to illiteration of the species. The above fully applies to man.

1.2.5. The main abiotic factors.

Recall once again that abiotic factors are properties of inanimate nature that directly or indirectly affect living organisms. Slide 3 shows the classification of abiotic factors.

Temperature  is the most important climatic factor. Depends on it metabolic rate  organisms and their geographical distribution. Any organism is able to live within a certain temperature range. And although for different types of organisms ( eurythermal and stenothermic) these intervals are different, for most of them the zone of optimal temperatures at which vital functions are carried out most actively and efficiently is relatively small. The temperature range in which life can exist is approximately 300 ° C: from -200 to +100 ° C. But most of the species and most of their activity are confined to an even narrower range of temperatures. Some organisms, especially in the resting stage, may exist for at least some time, at very low temperatures. Some types of microorganisms, mainly bacteria and algae, are able to live and multiply at temperatures close to the boiling point. The upper limit for bacteria of hot springs is 88 C, for blue-green algae - 80 C, and for the most resistant fish and insects - about 50 C. As a rule, the upper limit values ​​of the factor are more critical than the lower ones, although many organisms near the upper Tolerance limits are functioning more efficiently.

In aquatic animals, the range of tolerance to temperature is usually narrower than land animals, since the range of temperature variations in water is less than on land.

In terms of effects on living organisms, temperature variability is extremely important. Temperatures ranging from 10 to 20 ° C (average component 15 ° C) do not necessarily affect the organism in the same way as a constant temperature of 15 ° C. The vital activity of organisms that in nature are usually exposed to variable temperatures is completely or partially inhibited or slowed down by constant temperature. Using a variable temperature, it was possible to accelerate the development of grasshopper eggs by an average of 38.6% compared to their development at a constant temperature. It is not yet clear whether the accelerating effect is caused by the temperature fluctuations themselves or by the enhanced growth caused by a short-term increase in temperature and a non-compensating growth retardation as it decreases.

Thus, temperature is an important and very often limiting factor. Temperature rhythms largely control the seasonal and daily activity of plants and animals. Temperature often creates zonality and stratification in aquatic and terrestrial habitats.

Waterphysiologically necessary for any protoplasm. From an ecological point of view, it serves as a limiting factor both in terrestrial habitats and in aquatic ones, where its quantity is subject to strong fluctuations, or where high salinity promotes the loss of water by the body through osmosis. All living organisms, depending on their need for water, and consequently, from differences in habitat, are divided into a number of ecological groups: aquatic or hydrophilic  - permanently living in water; hygrophilic  - living in very wet habitats; mesophilic  - characterized by a moderate need for water and xerophilic  - living in dry habitats.

Amount of precipitation  and humidity - the main quantities measured in the study of this factor. The amount of precipitation depends mainly on the paths and the nature of large movements of air masses. For example, winds blowing from the ocean, leave most of the moisture on the slopes facing the ocean, resulting in a rain shadow beyond the mountains, contributing to the formation of the desert. Moving deep into the land, the air accumulates a certain amount of moisture, and the amount of precipitation increases again. Deserts are usually located behind high mountain ranges or along those shores where winds blow from vast inland dry areas rather than from the ocean, for example, the Nami desert in South-West Africa. The distribution of precipitation by seasons is an extremely important limiting factor for organisms. The conditions created by the uniform distribution of precipitation are completely different than during precipitation during one season. In this case, animals and plants have to endure periods of prolonged drought. As a rule, the uneven distribution of precipitation over the seasons is found in the tropics and subtropics, where the wet and dry seasons are often well pronounced. In the tropical belt, the seasonal rhythm of humidity regulates the seasonal activity of organisms in a manner similar to the seasonal rhythm of heat and light in temperate zones. Dew can be a significant, and in places with little rainfall, and a very important contribution to total precipitation.

Humidity  - A parameter characterizing the content of water vapor in the air. Absolute humidity  call the amount of water vapor per unit volume of air. In connection with the dependence of the amount of vapor held by air on temperature and pressure, the concept of relative humidity is the ratio of the steam contained in the air to the saturating steam at a given temperature and pressure. Since there is a daily rhythm of humidity in nature — an increase in the night and a decrease in the daytime, and its fluctuation vertically and horizontally, this factor, along with light and temperature, plays an important role in regulating the activity of organisms. Humidity changes the effects of temperature elevation. For example, under conditions of humidity close to critical, temperature has a more important limiting effect. Similarly, humidity plays a more critical role if the temperature is close to the limit values. Large reservoirs significantly soften the land climate, since the water is characterized by a large latent heat of vaporization and melting. In fact, there are two main types of climate: continental  with extremes of temperature and humidity and nautical,  which are characterized by less sharp fluctuations, due to the softening effect of large bodies of water.

The surface water supply available to living organisms depends on the amount of precipitation in a given area, but these values ​​do not always coincide. So, using underground sources, where water comes from other areas, animals and plants can get more water than from its receipt with precipitation. Conversely, rainwater sometimes sometimes becomes inaccessible to organisms.

Sun radiation  represents electromagnetic waves of various lengths. It is absolutely necessary for wildlife, as it is the main external source of energy. The spectrum of the distribution of solar radiation energy outside the earth’s atmosphere (Fig. 6) shows that about half of the solar energy is emitted in the infrared region, 40% in the visible and 10% in the ultraviolet and x-ray regions.

It should be borne in mind that the spectrum of the electromagnetic radiation of the Sun is very wide (Fig. 7) and its frequency ranges affect living matter in various ways. The Earth's atmosphere, including the ozone layer, selectively, that is, selectively in the frequency ranges, absorbs the energy of the electromagnetic radiation of the Sun and mainly radiation with a wavelength of 0.3 to 3 microns reaches the surface of the Earth. Longer and shortwave radiation is absorbed by the atmosphere.

With an increase in the sun's zenith distance, the relative content of infrared radiation increases (from 50 to 72%).

For living matter are important qualitative signs of light - wavelength, intensity and duration of exposure.

It is known that animals and plants react to changes in the wavelength of light. Color vision is common in different groups of animals spotty: it is well developed in some species of arthropods, fish, birds and mammals, but in other species of the same groups it may be absent.

The intensity of photosynthesis varies with the wavelength of light. For example, when light passes through water, the red and blue parts of the spectrum are filtered out and the resulting greenish light is poorly absorbed by chlorophyll. However, red algae have additional pigments (phycoerythrin) that allow them to use this energy and live deeper than green algae.

In both terrestrial and aquatic plants, photosynthesis is associated with light intensity by a linear relationship to an optimal level of light saturation, which in many cases is followed by a decrease in the intensity of photosynthesis at high intensities of direct sunlight. In some plants, such as eucalyptus, photosynthesis is not inhibited by direct sunlight. In this case, there is a compensation factor, as individual plants and entire communities adapt to different light intensities, becoming adapted to the shadow (diatoms, phytoplankton) or to direct sunlight.

Duration of daylight, or photoperiod, is a "time relay" or trigger mechanism, including a sequence of physiological processes leading to the growth, flowering of many plants, molting and accumulation of fat, migration and reproduction in birds and mammals and the onset of diapause in insects. Some higher plants bloom with longer day (long day plants), others bloom with less day (short day plants). In many organisms sensitive to a photoperiod, the setting of a biological clock can be changed by experimentally changing the photoperiod.

Ionizing radiation  knocks electrons out of atoms and attaches them to other atoms with the formation of pairs of positive and negative ions. Its source are radioactive substances contained in rocks, in addition, it comes from space.

Different types of living organisms are very different in their ability to withstand large doses of radiation. For example, a dose of 2 Sv (sivera) - causes the death of embryos of some insects at the stage of crushing, a dose of 5 Sv leads to the sterility of some species of insects, a dose of 10 Sv is absolutely lethal to mammals. As data of most studies show, fast-dividing cells are most sensitive to radiation.

The impact of low doses of radiation is more difficult to assess, since they can cause long-term genetic and somatic consequences. For example, exposure of pine to a dose of 0.01 Sv per day for 10 years caused a slowdown in growth rate, similar to a single dose of 0.6 Sv. An increase in the level of radiation in the medium above the background leads to an increase in the frequency of harmful mutations.

In higher plants, the sensitivity to ionizing radiation is directly proportional to the size of the cell nucleus, more precisely, the volume of chromosomes or the content of DNA.

In higher animals, no such simple relationship was found between sensitivity and cell structure; for them, the sensitivity of individual organ systems is more important. Thus, mammals are very sensitive even to low doses of radiation due to the slight damage caused by irradiation of the rapidly dividing hematopoietic tissue of the bone marrow. Even very low levels of chronically active ionizing radiation can cause the growth of tumor cells in bones and other sensitive tissues, which can manifest itself only many years after irradiation.

Gas compositionthe atmosphere is also an important climatic factor (Fig. 8). About 3-3.5 billion years ago, the atmosphere contained nitrogen, ammonia, hydrogen, methane and water vapor, and there was no free oxygen in it. The composition of the atmosphere was largely determined by volcanic gases. Due to the lack of oxygen, there was no ozone screen that delays the ultraviolet radiation of the sun. Over time, due to abiotic processes in the atmosphere of the planet, oxygen began to accumulate, the formation of the ozone layer began. Approximately in the middle of the Paleozoic, oxygen consumption was equal to its formation, during this period the O2 content in the atmosphere was close to modern - about 20%. Further, from the middle of the Devonian, fluctuations in the oxygen content are observed. At the end of the Paleozoic, there was a noticeable, approximately up to 5% of the current level, a decrease in the oxygen content and an increase in the carbon dioxide content, which led to climate change and, apparently, triggered an abundant "autotrophic" flowering that created fossil hydrocarbon fuels. This was followed by a gradual return to an atmosphere with a low carbon dioxide content and a high oxygen content, after which the O2 / CO2 ratio remains in the so-called vibrational steady-state equilibrium.

At present, the Earth's atmosphere has the following composition: oxygen ~ 21%, nitrogen ~ 78%, carbon dioxide ~ 0.03%, inert gases and impurities ~ 0.97%. Interestingly, oxygen and carbon dioxide concentrations are limiting for many higher plants. In many plants, it is possible to increase the efficiency of photosynthesis by increasing the concentration of carbon dioxide, but it is not well known that a decrease in the concentration of oxygen can also lead to an increase in photosynthesis. In experiments on legumes and many other plants, it was shown that lowering the oxygen content in the air to 5% increases the intensity of photosynthesis by 50%. Nitrogen also plays a crucial role. This is the most important nutrient element involved in the formation of protein structures of organisms. Wind has a limiting effect on the activity and distribution of organisms.

Wind it can even change the appearance of plants, especially in those habitats, for example, in alpine zones, where other factors have a limiting effect. It was experimentally shown that in open mountain habitats the wind limits the growth of plants: when the wall was built to protect the plants from the wind, the height of the plants increased. Storms are of great importance, although their action is purely local. Hurricanes and ordinary winds are able to carry animals and plants over long distances and thereby change the composition of communities.

Atmosphere pressureIt seems not to be a limiting factor of direct action, but it is directly related to the weather and climate, which have a direct limiting effect.

Water conditions create a peculiar habitat for organisms, which differs from terrestrial primarily in density and viscosity. Density   water about 800 times as well viscosity   about 55 times higher than that of air. Together with density   and viscosity the most important physicochemical properties of the aquatic environment are: temperature stratification, i.e., temperature variation over the depth of the water body and periodic temperature changes over time   and transparency water, which determines the light regime under its surface: photosynthesis of green and purple algae, phytoplankton, higher plants depends on transparency.

As in the atmosphere, plays an important role gas composition water environment. In aquatic habitats, the amount of oxygen, carbon dioxide and other gases dissolved in water and therefore available to organisms varies greatly in time. In water bodies with a high organic content, oxygen is a limiting factor of paramount importance. Despite the better solubility of oxygen in water compared to nitrogen, even in the most favorable case, water contains less oxygen than air, about 1% by volume. The solubility is influenced by the temperature of the water and the amount of dissolved salts: as the temperature decreases, the solubility of oxygen increases, and as salinity increases, it decreases. The oxygen supply in water is replenished due to diffusion from the air and photosynthesis of aquatic plants. Oxygen diffuses into the water very slowly, diffusion contributes to the wind and the movement of water. As already mentioned, the most important factor that ensures the photosynthetic production of oxygen is light that penetrates into the water column. Thus, the oxygen content varies in water depending on the time of day, time of year and location.

The content of carbon dioxide in water can also vary greatly, but in its behavior carbon dioxide differs from oxygen, and its ecological role is poorly understood. Carbon dioxide is highly soluble in water, in addition, CO2 enters the water, formed during respiration and decomposition, as well as from soil or underground sources. Unlike oxygen, carbon dioxide reacts with water:

with the formation of carbonic acid, which reacts with lime, forming carbonates CO22- and hydrogen carbonate HCO3-. These compounds maintain the concentration of hydrogen ions at a level close to the neutral value. A small amount of carbon dioxide in water increases the intensity of photosynthesis and stimulates the development of many organisms. A high concentration of carbon dioxide is a limiting factor for animals, as it is accompanied by a low oxygen content. For example, if too high a content of free carbon dioxide in the water, many fish die.

Acidity  - the concentration of hydrogen ions (pH) - is closely related to the carbonate system. Does the pH value range from 0? pH? 14: at pH = 7 neutral medium, at pH<7 - кислая, при рН>7 - alkaline. If acidity does not approach extreme values, then communities are able to compensate for changes in this factor — community tolerance for the pH range is quite significant. Acidity may serve as an indicator of the rate of general metabolism of a community. In waters with low pH, there are few nutrients, so productivity is extremely low here.

Salinity- content of carbonates, sulfates, chlorides, etc. - is another significant abiotic factor in water bodies. There are few salts in fresh waters, of which about 80% are carbonates. The content of mineral substances in the world ocean averages 35 g / l. Open ocean organisms are usually stenohaline, whereas coastal brackish water organisms are generally euryhaline. The concentration of salts in body fluids and tissues of most marine organisms is isotonic with the concentration of salts in seawater, so that there are no problems with osmoregulation.

Flow  not only greatly affects the concentration of gases and nutrients, but also directly acts as a limiting factor. Many river plants and animals are morphologically and physiologically specifically adapted to maintain their position in the stream: they have quite definite limits of tolerance to the flow factor.

Hydrostatic pressure  in the ocean is of great importance. With immersion in water at 10 m, the pressure increases by 1 atm (105 Pa). In the deepest part of the ocean, the pressure reaches 1000 atm (108 Pa). Many animals are able to tolerate sharp pressure fluctuations, especially if they have no free air in their bodies. Otherwise, gas embolism may develop. High pressures characteristic of large depths, as a rule, inhibit the processes of vital activity.

Soil is a layer of matter lying on top of the rocks of the earth's crust. The Russian scientist - naturalist Vasily Vasilyevich Dokuchaev in 1870 was the first to consider the soil as a dynamic rather than an inert environment. He proved that the soil is constantly changing and developing, and chemical, physical and biological processes take place in its active zone. The soil is formed as a result of a complex interaction of climate, plants, animals and microorganisms. Soviet soil scientist Vasily Robertovich Williams gave another definition of soil - this is a loose surface land horizon capable of producing crops. Plant growth depends on the content of essential nutrients in the soil and on its structure.

The soil contains four main structural components: mineral base (usually 50-60% of the total soil composition), organic matter (up to 10%), air (15-25%) and water (25-30%).

Mineral skeleton soil- It is an inorganic component that was formed from the parent rock as a result of its weathering.

Silica SiO2 occupies more than 50% of the mineral composition of the soil, from 1 to 25% comes from Al2O3 alumina, from 1 to 10% to iron oxides Fe2O3, from 0.1 to 5% to oxides of magnesium, potassium, phosphorus, calcium. The mineral elements that form the substance of the soil skeleton vary in size: from boulders and stones to sand grains — particles with a diameter of 0.02–2 mm; silt — particles with a diameter of 0.002–0.02 mm and smallest clay particles less than 0.002 mm in diameter. Their ratio determines mechanical soil structure . It is of great importance for agriculture. Clays and loams containing approximately equal amounts of clay and sand are usually suitable for plant growth, as they contain enough nutrients and are able to retain moisture. Sandy soils are drained faster and lose nutrients due to leaching, but they are more advantageous to use for early harvests, because their surface dries out in spring faster than in clay soils, which leads to better warming. With an increase in soil stony, its ability to retain water decreases.

Organic matter  Soil is formed by the decomposition of dead organisms, their parts and excrement. Not completely decomposed organic residues are called litter, and the final decomposition product — an amorphous substance in which it is no longer possible to recognize the original material — is called humus. Due to its physical and chemical properties, humus improves the structure of the soil and its aeration, as well as increases the ability to retain water and nutrients.

Simultaneously with the process of humification, vital elements pass their organic compounds into inorganic, for example: nitrogen - into ammonium ions NH4 +, phosphorus - into orthophosphations H2PO4-, sulfur - into sulfonations SO42-. This process is called mineralization.

The soil air, like the soil water, is located in the pores between the soil particles. Porosity increases from clay to loam and sand. There is free gas exchange between the soil and the atmosphere, as a result of which the gas composition of both media has a similar composition. Usually in the air of the soil, due to the respiration of the organisms inhabiting it, there is somewhat less oxygen and more carbon dioxide than in atmospheric air. Oxygen is essential for plant roots, soil animals, and decomposers that decompose organic matter into inorganic constituents. If bogging is underway, the soil air is displaced by water and the conditions become anaerobic. The soil gradually becomes acidic, as anaerobic organisms continue to produce carbon dioxide. The soil, if it is not rich in bases, can become extremely acidic, and this, along with the depletion of oxygen reserves, adversely affects soil microorganisms. Long-term anaerobic conditions lead to the death of plants.

Soil particles retain around themselves some water, which determines the soil moisture. Part of it, called gravitational water, can freely seep into the soil. This leads to the leaching of various mineral substances from the soil, including nitrogen. Water can also be held around individual colloidal particles in the form of a thin strong bound film. This water is called hygroscopic. It is adsorbed on the surface of the particles due to hydrogen bonds. This water is least accessible to the roots of plants and it is the latter that is retained in very dry soils. The amount of hygroscopic water depends on the content of colloidal particles in the soil, so in clay soils it is much more - about 15% of the soil mass than in sandy - about 0.5%. As the layers of water accumulate around the soil particles, it begins to fill first the narrow pores between these particles, and then it spreads to ever wider pores. Hygroscopic water gradually passes into the capillary, which is held around the soil particles by surface tension forces. Capillary water can rise along narrow pores and tubules from the groundwater level. Plants easily absorb capillary water, which plays the largest role in regular water supply. Unlike hygroscopic moisture, this water evaporates easily. Fine-grained soils, such as clay, retain more capillary water than coarse-grained, such as sands.

Water is necessary for all soil organisms. It enters living cells by osmosis.

Water is also important as a solvent for nutrients and gases absorbed from an aqueous solution by plant roots. It takes part in the destruction of the parent rock, the underlying soil, and in the process of soil formation.

The chemical properties of the soil depend on the content of mineral substances that are in it in the form of dissolved ions. Some ions are poisonous to plants, others are vital. The concentration of hydrogen ions in the soil (acidity) pH\u003e 7, that is, on average close to the neutral value. The flora of such soils is especially rich in species. Calcareous and saline soils have pH = 8 ... 9, and peat soils - up to 4. Specific vegetation develops on these soils.

The soil is inhabited by many species of plant and animal organisms that affect its physico-chemical characteristics: bacteria, algae, fungi or protozoa single-celled, worms and arthropods. Their biomass in different soils is equal (kg / ha): bacteria 1000-7000, microscopic fungi - 100-1000, algae 100-300, arthropods - 1000, worms 350-1000.

In the soil, the processes of synthesis, biosynthesis are carried out, various chemical reactions of transformation of substances associated with the activity of bacteria take place. In the absence of specialized groups of bacteria in the soil, their role is played by soil animals, which convert large plant residues into microscopic particles and thus make organic matter accessible to microorganisms.

Organic matter is produced by plants using mineral salts, solar energy and water. Thus, the soil loses the minerals that the plants have taken from it. In the forests, part of the nutrients is returned to the soil through leaf fall. Cultivated plants for some period of time withdraw from the soil much more nutrients than return to it. Usually the loss of nutrients is made up by the application of mineral fertilizers, which generally cannot be directly used by plants and must be transformed by microorganisms into a biologically accessible form. In the absence of such microorganisms, the soil loses its fertility.

The main biochemical processes take place in the top layer of soil up to 40 cm thick, since the largest number of microorganisms lives in it. Some bacteria are involved in the cycle of transformation of only one element, others - in the cycles of transformation of many elements. If bacteria mineralize organic matter - decompose organic matter into inorganic compounds, then protozoa destroy excessive amounts of bacteria. Earthworms, larvae of beetles, mites loosen the soil and thereby contribute to its aeration. In addition, they recycle hard-to-break down organic matter.

The abiotic environmental factors of living organisms also include relief factors (topography) . The influence of topography is closely related to other abiotic factors, as it can greatly affect the local climate and soil development.

The main topographical factor is the height above sea level. With altitude, average temperatures decrease, daily temperature drops, precipitation increases, wind speed and radiation intensity increase, atmospheric pressure and gas concentrations decrease. All these factors affect plants and animals, causing vertical zonality.

Mountain rangescan serve as climate barriers. Mountains also serve as barriers to the spread and migration of organisms and may play a role as a limiting factor in speciation.

Another topographical factor - slope exposure . In the northern hemisphere, the slopes facing the south receive more sunlight, so the light intensity and temperature are higher here than at the bottom of the valleys and on the slopes of the northern exposure. In the southern hemisphere, the opposite is true.

An important relief factor is also slope steepness . Steep slopes are characterized by rapid drainage and washing away of the soil; therefore, the soils here are thin and drier. If the slope exceeds 35b, the soil and vegetation is usually not formed, but scree of loose material is created.

Among the abiotic factors deserves special attention the fire   or fire . Currently, environmentalists have come to the unequivocal opinion that fire should be considered as one of the natural abiotic factors along with climatic, edaphic and other factors.

Fires as an environmental factor are of various types and leave behind various consequences. Riding or wild fires, that is, very intense and not amenable to containment, destroy all vegetation and all the organic matter of the soil, the consequences of ground fires are completely different. Mounted fires have a limiting effect on most organisms - the biotic community has to start all over again, with the little that is left, and it should take many years until the site becomes productive again. Field fires, on the contrary, have a selective effect: for some organisms they are more limiting, for others they are less limiting factors and thus contribute to the development of organisms with high tolerance to fires. In addition, small grass fires complement the action of bacteria, decomposing dead plants and accelerating the transformation of mineral nutrients into a form suitable for use by new generations of plants.

If ground fires occur regularly every few years, there is little deadwood on the ground, which reduces the likelihood of kronas to ignite. In forests that have not burned for more than 60 years, so much combustible bedding and dead wood accumulates that when it ignites, a high-level fire is almost inevitable.

The plants developed special adaptations to the fire, just as they did in relation to other abiotic factors. In particular, the buds of cereals and pines are hidden from fire in the depths of bundles of leaves or needles. In periodically burnt habitats, these plant species benefit, as fire contributes to their preservation, selectively promoting their prosperity. Broad-leaf breeds are deprived of protective devices from fire, it is destructive for them.

Thus, fires sustain only certain ecosystems. Deciduous and humid tropical forests, the balance of which was developed without the influence of fire, even a lowland fire can cause great damage, destroying the humus-rich upper soil horizon, leading to erosion and leaching of nutrients from it.

The question of "burn or not burn" is unusual for us. The effects of burning can be very different depending on the time and intensity. Due to his carelessness, people often cause an increase in the frequency of wild fires, so it is necessary to actively fight for fire safety in forests and recreation areas. In no case shall an individual have the right to intentionally or accidentally cause a fire in nature. At the same time, it is necessary to know that the use of fire by specially trained people is part of proper land use.

For abiotic conditions, all considered laws of the impact of environmental factors on living organisms are valid. Knowledge of these laws allows us to answer the question: why did different ecosystems form in different regions of the planet? The main reason is the peculiar abiotic conditions of each region.

Populations concentrate on a certain area and cannot be distributed everywhere with the same density, since they have a limited range of tolerance towards environmental factors. Therefore, each combination of abiotic factors is characterized by its own species of living organisms. Many variants of combinations of abiotic factors and species of living organisms adapted to them cause a variety of ecosystems on the planet.

1.2.6. Major biotic factors.

Areas of distribution and number of organisms of each species are limited not only by the conditions of the external inanimate environment, but also by their relations with organisms of other species. The immediate living environment of the body makes it   biotic environment , and the factors of this environment are called biotic . Representatives of each species are able to exist in such an environment where connections with other organisms provide them with normal living conditions.

There are the following forms of biotic relationships. If the positive results of relations for an organism are marked with a “+” sign, negative results with a “-” sign, and the lack of results is indicated by “0”, then the naturally occurring types of relationships between living organisms can be represented as tab. one.

This schematic classification gives a general idea of ​​the diversity of biotic relationships. Consider the characteristic features of the relationship of various types.

Competition  is in nature the most all-encompassing type of relationship in which two populations or two individuals in the struggle for the conditions necessary for life affect each other negatively .

Competition may be intraspecific   and interspecific . Intraspecific struggle occurs between individuals of the same species, interspecific competition takes place between individuals of different species. Competitive engagement may concern:

· Living space

· Food or nutrients

· Places of shelter and many other vital factors.

Competitive advantage is achieved in various ways. With the same access to a common resource, one type can have an advantage over the other due to:

· More intensive reproduction,

· Consumption of more food or solar energy,

· The ability to better protect themselves,

· Adapt to a wider range of temperatures, light levels or concentrations of certain harmful substances.

Interspecific competition, regardless of what underlies it, can lead either to establish a balance between the two species, or to replace a population of one species with another, or to one species displacing another in another place or cause it to switch to another. use of other resources. Determined that two ecologically identical and species needs cannot coexist in one place and sooner or later one competitor displaces another. This is the so-called exclusion principle or the Gause principle.

Populations of some species of living organisms avoid or reduce competition by moving to another region with acceptable conditions or switching to more difficult or difficult to digest food, or changing the time or place of production. For example, hawks feed in the daytime, owls eat at night; lions hunt larger animals, and leopards hunt smaller ones; For tropical forests, the existing stratification of animals and birds by tiers is typical.

From the principle of Gauze, it follows that each species in nature takes a certain peculiar place. It is determined by the position of the species in space, the functions it performs in the community and its relation to the abiotic conditions of existence. The place occupied by a species or organism in an ecosystem is called an ecological niche.   Figuratively speaking, if habitat is like the address of organisms of a given species, then an ecological niche is a profession, the role of an organism in its habitat.

The species occupies its ecological niche in order to fulfill the function reclaimed by it from other species only in its inherent way, thus mastering the habitat and at the same time forming it. Nature is very economical: even two species occupying the same ecological niche cannot sustainably exist. In competition, one species will crowd out another.

The ecological niche as a functional place of the species in the system of life cannot be empty for a long time - this is indicated by the rule of obligatory filling of ecological niches: the empty ecological niche is always naturally filled. An ecological niche as a functional place of a species in an ecosystem allows a form capable of developing new adaptations to fill this niche, however sometimes it takes considerable time. Often seemingly vacant ecological niches to a specialist are just a hoax. Therefore, a person should be extremely careful with the conclusions about the possibility of filling these niches by acclimatization (introduction). Acclimatization   - it is a complex of measures for the introduction of a species into new habitats, carried out in order to enrich natural or artificial communities with organisms useful to humans.

The heyday of acclimatization came in the twenties - forties of the twentieth century. However, over time, it became obvious that either the experiments on acclimatization of the species were unsuccessful, or, worse, brought very negative results - the species became pests or spread dangerous diseases. For example, ticks that were the causative agents of varroatosis, which killed a large number of bee colonies, were introduced with the Far Eastern bee acclimatized in the European part. It could not have been otherwise: new species placed in a strange ecosystem with an actually occupied ecological niche supplanted those who had already performed similar work. New species did not meet the needs of the ecosystem, sometimes had no enemies, and therefore could multiply rapidly.

A classic example of this is the introduction of rabbits to Australia. In 1859, rabbits were brought to Australia from England for sport hunting. Natural conditions turned out to be favorable for them, and local predators, dingos, were not dangerous, as they did not run fast enough. As a result, the rabbits bred so much that the vegetation of pastures was destroyed in vast territories. In some cases, the introduction into the ecosystem of the natural enemy of an alien pest brought success in combating the latter, but it is not as simple as it seems at first glance. The imported enemy would not necessarily concentrate on exterminating his usual loot. For example, foxes, introduced to Australia to kill rabbits, found in abundance easier prey — local marsupials, without delivering the planned sacrifice of particular trouble.

Competitive relations are clearly observed not only at the interspecific, but also at the intraspecific (population) level. With the growth of the population, when the number of its individuals approaches saturation, internal physiological mechanisms of regulation come into play: mortality increases, fertility decreases, stressful situations arise, fights. The study of these issues is engaged in population ecology.

Competitive relations are one of the most important mechanisms for the formation of the species composition of communities, the spatial distribution of the types of populations and the regulation of their numbers.

Since the structure of the ecosystem is dominated by food interactions, the most characteristic form of interaction of species in food chains is predation in which an individual of one species, called a predator, feeds on organisms (or parts of organisms) of another species, called a prey, and the predator lives separately from the prey. In such cases, it is said that two species are involved in a predator – prey relationship.

The victim species have developed a whole range of protective mechanisms in order not to become easy prey for the predator: the ability to quickly run or fly, the release of chemicals with a smell that frightens the predator or even poison it, possessing thick skin or armor, protective coloration or the ability to change color.

Predators also have several ways of prey extraction. Carnivores, unlike herbivores, are usually forced to chase and catch up with their prey (compare, for example, herbivorous elephants, hippopotamuses, cows with carnivorous cheetahs, panthers, etc.). Some predators are forced to run fast, others reach their goal, hunting in packs, others catch mostly sick, wounded and inferior individuals. Another way of providing yourself with animal food is the way man has gone - the invention of fishing gear and the domestication of animals.

Every kind of living organism lives in certain conditions  - in water, on the ground, in the soil or in the body of another organism. So, fish, crayfish, mollusks and other aquatic animals, many plants spend their entire lives in water.  Most plants, animals and birds live in land-air environment.

Everything that surrounds living organisms is called their habitat or environment.

Habitat is a  all bodies (living and non-living), as well as natural phenomena that directly or indirectly affect organisms.

The individual components of the environment that affect organisms are called environmental factors. Among them are the factors of animate and inanimate nature.

To inanimate factors, or abiotic factors,  include light, temperature, water, air, wind, atmospheric pressure.

Wildlife factors, or biotic factors,  - these are any interactions of living organisms. Thus, some organisms can serve as food for others, or, conversely, by eating and reducing feed reserves, thereby causing a reduction in the number of other species.

In a separate group of factors highlighted all kinds of human activityaffecting living organisms.

The relationship of living organisms with the environment, as well as the community of living organisms is studied by science ecology  (from the Greek word oikos - dwelling, and logos - science). Therefore, environmental factors are called ecological.

For the life of organisms that make up the natural community, certain conditions. Living conditions depend on the influence of various environmental factors.

You already know that for almost all life on Earth energy source is the sun. Plants during photosynthesis convert the energy of the sun into the energy of organic matter. Herbivores eat plants and use substances accumulated by plants to build their body and get energy. Thus, a significant part of the organic matter of plants goes into the body of herbivorous organisms and is spent on building new cells and on obtaining energy. Herbivorous animals eat predators.

In this way, plants play a crucial role in the natural communitytherefore we will consider the features of natural communities by their example.

All environmental factors influence the plant and are necessary for their life. But especially drastic changes in the appearance and in the internal structure of the plant cause such inanimate factorslike light, temperature, humidity.

One of the main abiotic factors is sunlight  - the main source of energy entering the Earth. Due to the energy of sunlight in plants, photosynthesis occurs. It also affects other functions of the plant organism - its growth, flowering, fruiting, seed germination.

According to the demands on the intensity of illumination, there are three groups of plants:  photophilous, shade-loving and shade-tolerant.

Light-loving plants  They live only in open sunlit places. They are widely distributed in dry steppes and semi-deserts, high-mountain meadows, wastelands, where rare vegetation cover and plants do not shade each other. To light-loving include   steppe and meadow grasses, mother and stepmother, stonecrop, weeds, wheat, sunflower, from tree species - pine, birch, larch, white acacia.

Shade plants  do not tolerate direct sunlight and grow well only in shady places. These are herbaceous plants of spruce forests and oak forests, for example oxillus, raven eye, double-glazed myannik, anemone, many forest ferns and mosses.

Shade-tolerant plants  grow best in direct sunlight, but can also tolerate shading. This group of plants includes many tree species with dense crowns, in which part of the leaves is strongly shaded ( linden, oak, ash), many herbaceous plants of forests, forest edges and meadows.

An important abiotic environmental factor is temperature. Temperature fluctuations on the globe reach wide limits: from + 50-60 ° C in deserts to -70-80 ° C in Antarctica, but life exists in such extreme conditions.

Each species of living organisms has adapted to a specific temperature regime. But for all plants, both overheating and excessive cooling are dangerous.

The effect of excessively high temperatures  can cause dryness, burns, destruction of chlorophyll in plants, disruption of vital processes and lead to death.

High temperatures, often combined with a lack of moisture, are often exposed to light-loving plants. These plants have developed various adaptations to avoidharmful effects of overheating:  vertical position of the leaves, reducing the leaf surface, the development of spines (in cacti), the ability to store a large amount of water, a well-developed root system, dense pubescence, giving the leaves a light color and enhancing the reflection of incident light.

Cold  may also adversely affect plants. When water freezes in the intercellular spaces and inside the cell, ice crystals form, causing cell damage and death.

Plants in cold areas have very small leaves and small sizes (for example, dwarf birch and dwarf willow). Their height corresponds to the depth of the snow cover, since all the parts protruding above the snow die.

In some shrubs and trees, growth begins to dominate in the horizontal direction, for example, cedar elfin wood. Their branches spread along the ground and do not rise above the usual depth of snow cover.

In the cold season, the plants slow down all life processes. Plants shed their foliage. In many herbaceous plants, the aboveground organs die off. Some aquatic plants sink to the bottom of reservoirs or form wintering buds.

Also an important abiotic factor is humidity, since no organism can exist without water. The source of water for plants is precipitation, water bodies, groundwater, dew and fog. In desert plants, dry steppes, water makes up from 30 to 65% of the total mass, in forest-steppe plants - up to 70-80%, and in moisture-loving plants it reaches 90%.

In relation to the humidity of the plant can be divided into three groups.

1. Plants of aquatic and excessively wetted habitats.

2. Plants dry habitats with high drought tolerance.

3. Plants living in medium (sufficient) moisture conditions.

The plants belonging to these ecological groups have characteristic features of the external and internal structure.

We now turn to the consideration of biotic factors and find out how living organisms affect each other.

Animals feed on plants, pollinate them, spread fruits and seeds. Large plants can shade young, small. Some plants use others as a support.

With every year increases the impact of human activity on nature. Man drains the swamps and irrigates the drylands, creating favorable conditions for growing crops. It introduces new, highly productive and disease-resistant plant varieties. Man contributes to the preservation and dissemination of valuable plants.

But human activity can harm nature. So, improper irrigation causes swampysoil salinization  and often leads to deaths growlower. Due to deforestation fertile soil layer is destroyed  and even deserts can form. There are a lot of similar examples, and all of them testify to the fact that a person exerts a huge influence on the plant world and nature as a whole.

The life of organisms depends on many conditions: temperature. light, humidity, other organisms. Without environment, living organisms are not able to breathe, feed, grow, develop, give offspring.

Environmental factors

The environment is a habitat for organisms with a specific set of conditions. In nature, the plant or animal organism is exposed to air, light, water, rocks, fungi, bacteria, other plants and animals. All of the listed environmental components are called environmental factors. The study of the relationship of organisms with the environment is engaged in science - ecology.

Influence of inanimate factors on plants

Lack or excess of any factor inhibits the body: reduces the rate of growth and metabolism, causes deviations from normal development. One of the most important environmental factors, especially for plants, is light. Its deficiency adversely affects photosynthesis. Plants grown with a lack of light, have pale, long and unstable shoots. With strong light and high air temperature, plants can get burned, which leads to tissue necrosis.

When the temperature of air and soil decreases, the growth of plants slows down or stops altogether, the leaves wither and turn black. The lack of moisture leads to wilting of plants, and its excess makes it difficult to breathe the roots.

Plants formed adaptations to life at very different values ​​of environmental factors: from bright light to darkness, from cold to heat, from abundance of moisture to great dryness.

Plants growing in the light are squat, with short shoots and rosette leaf arrangement. Often the leaves are shiny, which contributes to the reflection of light. Shoots of plants growing in the dark, elongated in height.

In deserts, where high temperatures and low humidity, leaves are small or completely absent, which prevents the evaporation of water. Many desert plants form white pubescence, which contributes to the reflection of the sun's rays and protection from overheating. In cold climates, creeping plants are common. Their shoots with buds hibernate under snow and are not exposed to low temperatures. In frost-resistant plants, organic substances accumulate in the cells, increasing the concentration of cell sap. This makes the plant more durable in winter.

Influence of inanimate factors on animals

Animal life also depends on the factors of inanimate nature. At unfavorable temperatures, growth and puberty of animals slow down. The adaptation to the cold climate is the down, feather and woolen cover in birds and mammals. Of great importance in regulating body temperature are the peculiarities of animal behavior: active movement to places with more favorable temperatures, the creation of shelters, changes in activity at different times of the year and day. To experience the adverse winter conditions bears, gophers, hedgehogs hibernate. In the hottest hours, many birds hide in the shade, spread their wings and open their beak.

Animals - inhabitants of the desert, have a variety of adaptations to the transfer of dry air and high temperature. The elephant turtle stores water in the bladder. Many rodents are content with water only from the poor. Insects, escaping from overheating, regularly rise into the air or burrow into the sand. In some mammals, water is formed from deposited fat (camels, fat-tailed sheep, fat-tailed jerboas).

Ecology is one of the main components of biology, which studies the interaction of the environment with organisms. The environment includes various factors of animate and inanimate nature. They can be both physical and chemical. Among the first are the air temperature, sunlight, water, soil structure and the thickness of its layer. The factors of inanimate nature also include the composition of the soil, air and substances dissolved in water. In addition, there are also biological factors - organisms that live in such an area. Ecology was first talked about in the 60s of the last century; it arose from a discipline such as natural history, which was engaged in observing organisms and their description. The rest of the article will describe the various phenomena that form the environment. Find out also what are the factors of inanimate nature.

general information

To begin with, we will determine why organisms live in particular places. This question was asked by naturalists during a study of the globe, when they made a list of all living beings. Then there were two characteristic features that were observed throughout the territory. The first is that in each new area new species are defined that were not previously found. They add to the list of officially registered. Secondly, regardless of the growing number of species, there are several main types of organisms that are concentrated in one place. So biomes are large communities that live on land. Each group has its own structure, in which vegetation dominates. But why in different parts of the globe, even at a great distance from each other, you can find similar groups of organisms? Let's figure it out.

Person

In Europe and America there is a perception that man is created to conquer nature. But today it has become clear that people are a component part of the habitat, and not vice versa. Therefore, society will survive only if nature is alive (plants, bacteria, fungi and animals). The main task of mankind is to preserve the ecosystem of the Earth. But in order to decide how not to act, we need to study the laws of the interaction of organisms. Factors of inanimate nature have a special meaning in human life. For example, it is no secret how important solar energy is. It provides a stable flow of many processes in plants, including cultural ones. They grow people, providing themselves with food.

Ecological factors of inanimate nature

In areas that have a constant climate, biomes of the same type live. What factors of inanimate nature in general exist? Let's figure it out. Vegetation is determined by climate, and the appearance of the community - by vegetation. The factor of inanimate nature is the sun. Near the equator, the rays fall vertically to the ground. Due to this, tropical plants get more ultraviolet light. The intensity of the rays that fall in the high latitudes of the Earth is weaker than near the equator.

The sun

It should be noted that due to the tilting of the earth's axis in different areas, the air temperature varies. Except the tropics. The sun is responsible for the temperature of the environment. For example, due to the vertical rays, in tropical areas the heat is constantly kept. In such conditions, plant growth is accelerated. Temperature variations affect the species diversity of a territory.

Humidity

Inanimate factors are interrelated. So, the humidity depends on the amount of ultraviolet radiation and the temperature. Warm air retains water vapor better than cold. During air cooling, 40% of moisture condenses, falling to the ground in the form of dew, snow or rain. In the equatorial region, warm air currents rise, thin out, and then cool. As a result, in some areas that are located near the equator, precipitation falls in huge quantities. Examples include the Amazon Basin, which is located in South America, and the Congo River Basin in Africa. Due to the large amount of rainfall there are tropical forests. In areas where air masses dissipate to the north and south at the same time, and the air, cooling, again descends to the ground, stretches of desert. Further north and south, in the latitudes of the United States, Asia and Europe, the weather is constantly changing - due to strong winds (sometimes from the tropics and sometimes from the polar, cold side).

The soil

The third factor of inanimate nature is soil. It has a strong effect on the distribution of organisms. It is formed on the basis of destroyed bedrock with the addition of organic substances (dead plants). If there is no necessary amount of minerals, the plant will develop poorly, in the future it may completely die. Soil is of particular importance in human agricultural activities. As you know, people grow different crops, which are then eaten. If the composition of the soil is unsatisfactory, then, accordingly, the plants will not be able to get all the necessary substances from it. And this, in turn, will lead to crop losses.

Wildlife factors

Any plant does not develop separately, but interacting with other representatives of the environment. Among them are mushrooms, animals, plants and even bacteria. The connection between them can be very different. Starting from beneficial benefits to each other and ending with a negative impact on a particular organism. Symbiosis is a model of interaction between various individuals. People call this process "cohabitation" of different organisms. Equally important in these relations are the factors of inanimate nature.

Examples