BUT biotic factors. To abiotic factors ground environment primarily climatic factors

The abiotic factors of the terrestrial environment primarily include climatic factors. Let's consider the main ones.

1. Light or solar radiation. Biological influence sunlight depends on its intensity, duration of action, spectral composition, daily and seasonal frequency.

The radiant energy coming from the Sun propagates in space in the form electromagnetic waves: ultra-violet rays(wavelength l< 0,4 мкм), видимые лучи (l = 0,4 ¸ 0,75 мкм) и infrared rays(l > 0.75 µm).

Ultraviolet rays are characterized by the highest quantum energy and high photochemical activity. In animals, they contribute to the formation of vitamin D and the synthesis of pigments by skin cells, in plants they have a shaping effect and contribute to the synthesis of biologically active compounds. Ultraviolet radiation with a wavelength of less than 0.29 microns is detrimental to all living things. However, thanks to ozone shield only a small part of it reaches the Earth's surface.

The visible part of the spectrum is especially great importance for organisms. Thanks to visible light Plants have developed a photosynthesis apparatus. For animals, the light factor is primarily necessary condition orientation in space and time, and also participates in the regulation of many life processes.

Infrared radiation raises the temperature natural environment and the organisms themselves, which is especially important for cold-blooded animals. In plants, infrared rays play a significant role in transpiration (evaporation of water from the surface of the leaves removes excess heat) and promote absorption by plants carbon dioxide.

2. Temperature affects everything in life important processes. First of all, it determines the speed and nature of the course of metabolic reactions in organisms.

The optimum temperature factor for most organisms is within 15 ¸ 30 0 С, however, some living organisms withstand its significant fluctuations. For example, certain types bacteria and blue-green algae can exist in hot springs at a temperature of about 80 0 C. Polar waters with temperatures from 0 to -2 0 C are inhabited by various representatives of the flora and fauna.

3. Humidity atmospheric air related to saturation with water vapor. Seasonal and diurnal fluctuations in humidity, along with light and temperature, regulate the activity of organisms.

In addition to climatic factors importance for living organisms gas composition atmosphere. It is relatively constant. The atmosphere consists mainly of nitrogen and oxygen with small amounts of carbon dioxide, argon and other gases. Nitrogen is involved in the formation of protein structures of organisms, oxygen provides oxidative processes.

Abiotic factors aquatic environment- This:

1 - density, viscosity, mobility of water;

Test "Abiotic environmental factors"

1. Signal for the beginning of the autumn migration of insectivorous birds:

1) lowering the temperature environment 2) reduction daylight hours

3) lack of food 4) increased humidity and pressure

2. The number of squirrels in the forest zone is NOT affected by:

1) change of cold and warm winters 2) harvest of spruce cones

3. Abiotic factors include:

1) the competition of plants for the absorption of light 2) the influence of plants on animal life

3) temperature change during the day 4) human pollution

4. The factor limiting the growth of herbaceous plants in a spruce forest is a disadvantage:

1) light 2) heat 3) water 4) minerals

5. What is the name of a factor that deviates significantly from the optimal value for the species:

1) abiotic 2) biotic

3) anthropogenic 4) limiting

6. The signal for the onset of leaf fall in plants is:

1) an increase in the humidity of the environment 2) a reduction in the length of daylight hours

3) decrease in the humidity of the environment 4) increase in the temperature of the environment

7. Wind, precipitation, dust storms are factors:

1) anthropogenic 2) biotic

3) abiotic 4) limiting

8. The reaction of organisms to a change in the length of daylight hours is called:

1) microevolutionary changes 2) photoperiodism

3) phototropism 4) unconditioned reflex

9. Abiotic environmental factors include:

1) undermining the roots by wild boars 2) an invasion of locusts

3) formation of bird colonies 4) heavy snowfall

10. Of the listed phenomena, daily biorhythms include:

1) migration of marine fish for spawning

2) opening and closing flowers angiosperms

3) bud break in trees and shrubs

4) opening and closing shells in mollusks

11. What factor limits the life of plants in the steppe zone?

1) high temperature 2) lack of moisture

3) lack of humus 4) excess of ultraviolet rays

12. The most important abiotic factor mineralizing organic residues in the biogeocenosis of the forest are:

1) frosts 2) fires

3) winds 4) rains

13. The abiotic factors that determine the population size include:

3) decrease in fertility 4) humidity

14. The main limiting factor for plant life in Indian Ocean is a disadvantage:

1) light 2) heat

3) mineral salts 4) organic matter

15. To abiotic environmental factors applies to:

1) soil fertility 2) big variety plants

3) the presence of predators 4) air temperature

16. The reaction of organisms to the length of the day is called:

1) phototropism 2) heliotropism

3) photoperiodism 4) phototaxis

17. Which of the factors regulates seasonal phenomena in the life of plants and animals?

1) temperature change 2) air humidity level

3) the presence of shelter 4) the length of the day and night

18. Which of the following factors inanimate nature most significantly affects the distribution of amphibians?

1) light 2) carbon dioxide content

3) air pressure 4) humidity

19. cultivated plants do not grow well on swampy soil, as in it:

1) insufficient oxygen content

2) methane is formed

3) excess content of organic matter

4) contains a lot of peat

20. What adaptation contributes to the cooling of plants when the air temperature rises?

1) a decrease in the metabolic rate 2) an increase in the intensity of photosynthesis

3) a decrease in the intensity of breathing 4) an increase in the evaporation of water

21. What adaptation in shade-tolerant plants provides more efficient and complete absorption of sunlight?

1) small leaves 2) large leaves

3) thorns and spines 4) wax coating on the leaves

Answers: 1 – 2; 2 – 1; 3 – 3; 4 – 1; 5 – 4;

6 – 2; 7 – 3; 8 – 2; 9 – 4; 10 – 2; 11 – 2;

12 – 2; 13 – 4; 14 – 1; 15 – 4; 16 – 3;

17 – 4; 18 – 4; 19 – 1; 20 – 4; 21 – 2.

Abiotic factors are factors space (solar radiation) climatic (light, temperature, humidity, atmospheric pressure, precipitation, air movement), edaphic or soil factors (mechanical composition of the soil, moisture capacity, air permeability, soil density), orographic factors (relief, height above sea level, slope exposure), chemical factors (gas composition of air, salt composition and acidity of water and soil solutions). Abiotic factors affect living organisms (directly or indirectly) through certain aspects of metabolism. Their peculiarity is the one-sidedness of the impact: the body can adapt to them, but does not have a significant effect on them.

I. Space Factors

The biosphere, as a habitat for living organisms, is not isolated from the complex processes taking place in outer space, and not only directly related to the Sun. Cosmic dust, meteoritic matter falls on the Earth. The Earth periodically collides with asteroids, approaches comets. Substances and waves resulting from flares pass through the Galaxy supernovae. Of course, our planet is most closely connected with the processes taking place on the Sun, with the so-called solar activity. The essence of this phenomenon is the transformation of the energy accumulated in the magnetic fields of the Sun into the energy of the movement of gaseous masses, fast particles, and short-wave electromagnetic radiation.

The most intense processes are observed in the centers of activity, called active regions, in which the magnetic field is strengthened, regions of increased brightness appear, as well as the so-called sunspots. Explosive energy releases can occur in active regions, accompanied by plasma ejections, the sudden appearance of solar cosmic rays, amplification of shortwave and radio emission. It is known that changes in the level of flare activity are cyclic in nature with a normal cycle of 22 years, although fluctuations with a frequency of 4.3 to 1850 years are known. Solar activity affects a number of life processes on Earth - from the occurrence of epidemics and bursts of births to major climate transformations. This was shown back in 1915 by the Russian scientist A.L. Chizhevsky, the founder of a new science - heliobiology (from the Greek helios - Sun), which considers the impact of changes in solar activity on the Earth's biosphere.

Thus, among the most important space factors includes electromagnetic radiation associated with solar activity with wide range wavelengths. The absorption of short-wavelength radiation by the Earth's atmosphere leads to the formation protective shells, in particular the ozonosphere. Among other cosmic factors, the corpuscular radiation of the Sun should be mentioned.

solar corona ( top part solar atmosphere), consisting mainly of ionized hydrogen atoms - protons - with an admixture of helium, is constantly expanding. Leaving the corona, this flow of hydrogen plasma propagates in the radial direction and reaches the Earth. They call him solar wind. It fills the whole area solar system; and constantly flows around the Earth, interacting with its magnetic field. It is clear that this is due to the dynamics of magnetic activity (for example, magnetic storms) and directly affects life on Earth.

Changes in the ionosphere in the polar regions of the Earth are also associated with solar cosmic rays, which cause ionization. With powerful flashes solar activity the impact of solar cosmic rays can briefly exceed the usual background of galactic cosmic rays. At present, science has accumulated a lot of factual materials illustrating the influence of cosmic factors on biospheric processes. In particular, the sensitivity of invertebrates to changes in solar activity has been proven, a correlation of its variations with the dynamics of the human nervous and cardiovascular systems, as well as with the dynamics of diseases - hereditary, oncological, infectious, etc., has been established.

Features of the impact on the biosphere from cosmic factors and manifestations of solar activity are that the surface of our planet is separated from the Cosmos by a powerful layer of matter in gaseous state, i.e., the atmosphere.

II. climatic factors

The most important climate-forming function belongs to the atmosphere as an environment that perceives cosmic and solar-related factors.

1. Light. Energy solar radiation propagates in space in the form of electromagnetic waves. About 99% of it is rays with a wavelength of 170-4000 nm, including 48% in the visible part of the spectrum with a wavelength of 400-760 nm, and 45% in the infrared (wavelength from 750 nm to 10 "3 m) , about 7% - to ultraviolet (wavelength less than 400 nm).In the processes of photosynthesis, the most important role plays photosynthetically active radiation (380-710 nm).

The amount of solar radiation energy coming to the Earth (to the upper boundary of the atmosphere) is almost constant and is estimated at 1370 W/m2. This value is called the solar constant.

Passing through the atmosphere, solar radiation is scattered by gas molecules, suspended impurities (solid and liquid), absorbed by water vapor, ozone, carbon dioxide, dust particles. Scattered solar radiation partially reaches the earth's surface. His visible part creates light during the day in the absence of direct sunlight, for example, in heavy cloud cover.

The energy of solar radiation is not only absorbed by the Earth's surface, but is also reflected by it in the form of a stream of long-wave radiation. Lighter colored surfaces reflect light more intensely than darker ones. So, pure snow reflects 80-95%, polluted - 40-50, chernozem soil - 5-14, light sand - 35-45, forest canopy - 10-18%. The ratio of solar radiation reflected by the surface to the incoming is called albedo.

The radiant energy of the Sun is associated with the illumination of the earth's surface, which is determined by the duration and intensity luminous flux. Plants and animals in the process of evolution have developed deep physiological, morphological and behavioral adaptations to the dynamics of illumination. All animals, including humans, have so-called circadian (daily) rhythms of activity.

The requirements of organisms for a certain duration of dark and light time are called photoperiodism, and seasonal fluctuations in illumination are especially important. The progressive trend towards a decrease in the length of daylight hours from summer to autumn serves as information to prepare for wintering or hibernation. Since photoperiodic conditions depend on latitude, a number of species (primarily insects) can form geographic races that differ in threshold day length.

2. Temperature

Temperature stratification is a change in water temperature along the depth of a water object. Continuous, temperature change is characteristic of any ecological systems. Often the word "gradient" is used to denote such a change. However, the temperature stratification of water in a reservoir is a specific phenomenon. Yes, during the summer surface water heat up more than deep ones. Since warmer water has a lower density and lower viscosity, its circulation occurs in the surface, heated layer and it does not mix with denser and more viscous cold water. An intermediate zone with a sharp temperature gradient forms between the warm and cold layers, which is called the thermocline. General temperature regime, associated with periodic (annual, seasonal, daily) temperature changes, is also the most important condition for the habitat of living organisms in water.

3. Humidity. Humidity is the amount of water vapor in the air. The lower layers of the atmosphere are richest in moisture (up to a height of 1.5-2.0 km), where approximately 50% of all atmospheric moisture is concentrated. The content of water vapor in the air depends on the temperature of the latter.

4. Precipitation is water in liquid (drops) or solid state that falls on the earth. surface from clouds or deposited directly from the air due to condensation of water vapor. Rain, snow, drizzle, freezing rain, snow grains, ice pellets, hail can fall from the clouds. The amount of precipitation is measured by the thickness of the layer of fallen water in millimeters.

Precipitation is closely related to air humidity and is the result of water vapor condensation. Due to condensation in the surface air layer, dews and fogs are formed, and at low temperatures moisture crystallization is observed. Condensation and crystallization of water vapor in higher layers of the atmosphere form clouds different structure and cause precipitation. Separate wet (humid) and dry (arid) zones the globe. The maximum amount of precipitation falls in the tropical forest zone (up to 2000 mm / year), while in arid zones (for example, in deserts) - 0.18 mm / year.

Precipitation - the most important factor, which influences the processes of pollution of the natural environment. The presence of water vapor (fog) in the air with the simultaneous entry of, for example, sulfur dioxide into it leads to the fact that the latter turns into sulfurous acid, which is oxidized to sulfuric acid. In conditions of stagnant air (calm), a stable toxic fog is formed. Similar Substances can be washed out of the atmosphere and deposited on land and ocean surfaces. A typical result is the so-called acid rain. Particulate matter in the atmosphere can serve as nuclei for moisture condensation, causing different forms precipitation.

5. Atmospheric pressure. Normal pressure is considered to be 101.3 kPa (760 mm Hg). Within the surface of the globe, there are areas of high and low pressure, and seasonal and daily minima and pressure maxima are observed at the same points. Marine and continental types of atmospheric pressure dynamics also differ. Periodically occurring areas of low pressure are called cyclones and are characterized by powerful air currents moving in a spiral and moving in space towards the center. Cyclones are associated with unstable weather and large quantity precipitation.

In contrast, anticyclones are characterized by stable weather, low wind speeds, and, in some cases, temperature inversions. During anticyclones, unfavorable meteorological conditions from the point of view of the transfer and dispersion of impurities can occur.

6. Air movement. The reason for the formation of wind currents and movement air masses is the uneven heating of different parts of the earth's surface, associated with pressure drops. The wind flow is directed towards lower pressure, but the rotation of the Earth also affects the circulation of air masses on a global scale. In the surface layer of air, the movement of air masses affects all meteorological factors of the environment, i.e. on climate, including temperature, humidity, land and sea evaporation, and plant transpiration.

It is especially important to know that wind flows are the most important factor in the transfer, dispersion and fallout of pollutants entering the atmosphere from industrial enterprises, thermal power plants, and transport. The strength and direction of the wind determine the modes of environmental pollution. For example, calm in combination with air temperature inversion is considered as adverse meteorological conditions (NMC) that contribute to long-term severe air pollution in areas of industrial enterprises and human habitation.

General patterns of distribution of levels and regional regimes of environmental factors

The geographic envelope of the Earth (like the biosphere) is heterogeneous in space, it is differentiated into territories that differ from each other. It is successively divided into physical-geographical zones, geographical zones, intrazonal mountainous and lowland regions and sub-regions, subzones, etc.

The physical-geographical belt is the largest taxonomic unit of the geographical shell, which is composed of a series geographical areas, which are close in terms of heat balance and humidification regime.

There are, in particular, the Arctic and Antarctic, subarctic and subantarctic, northern and southern temperate and subtropical, subequatorial and equatorial belts.

geographic (aka.–natural, landscape) zone–this is a significant part of the physiographic belt with special character geomorphological processes, with special types climate, vegetation, soils, flora and fauna.

The zones have predominantly (although by no means always) broadly elongated outlines and are characterized by similar natural conditions, a certain sequence depending on the latitudinal position - this is latitudinal geographical zonality, due mainly to the nature of the distribution of solar energy over latitudes, i.e. with a decrease in its arrival from the equator to the poles and uneven moistening.

Along with the latitude, there is also a typical mountainous areas vertical (or altitudinal) zonality, i.e., a change in vegetation, wildlife, soils, climatic conditions, as you rise from sea level, mainly associated with a change heat balance: air temperature difference is 0.6-1.0 °C for every 100 m of altitude.

III. edaphicor soilfactors

According to the definition of V. R. Williams, the soil is a loose surface horizon of the land, capable of producing a crop of plants. The most important property of the soil is its fertility, i.e. the ability to provide organic and mineral nutrition to plants. Fertility depends on the physical and chemical properties of the soil, which together are edaphogenic (from the Greek. edafos - soil), or edaphic, factors.

1. Mechanical composition of the soil. Soil is a product of physical, chemical and biological transformation (weathering) rocks, is a three-phase medium containing solid; liquid and gaseous components. It is formed as a result of complex interactions of climate, plants, animals, microorganisms and is considered as a bio-inert body containing living and non-living components.

There are many types of soils in the world associated with different climatic conditions and the specifics of the processes of their formation. Soils are characterized by a certain zonality, although the belts are by no means always continuous. Among major types Soils of Russia can be called tundra, podzolic soils of the taiga-forest zone (the most common), chernozems, gray forest soils, chestnut soils (to the south and east of chernozems), brown soils (characteristic of dry steppes and semi-deserts), red soils, solonchaks, etc. .

As a result of the movement and transformation of substances, the soil is usually divided into separate layers, or horizons, the combination of which forms a soil profile on the section (Fig. 2), which in general looks like this:

the uppermost horizon (BUT 1 ), containing decay products of organic matter, is the most fertile. It is called humus or humus, has a granular-lumpy or layered structure. It is in it that complex physico-chemical processes take place, as a result of which elements of plant nutrition are formed. Humus has a different color.

Above the humus horizon there is a layer of plant litter, which is commonly called the litter (A 0 ). It consists of undecomposed plant remains.

Below the humus horizon there is an infertile whitish layer 10-12 cm thick (A 2). Nutrients washed out of it with water or acids. Therefore, it is called the leaching or leaching (eluvial) horizon. Actually, it is a podzolic horizon. Quartz and aluminum oxide are weakly dissolved and remain in this horizon.

Even lower lies the parent rock (C).

Abiotic environmental factors include the substrate and its composition, humidity, light and other types of radiation in nature, and its composition, and microclimate. It should be noted that temperature, air composition, humidity and light can be conditionally referred to as "individual", and the substrate, climate, microclimate, etc. - to "complex" factors.

The substrate (literally) is the place of attachment. For example, for woody and herbaceous forms of plants, for soil microorganisms, this is the soil. In some cases, the substrate can be considered a synonym for habitat (for example, soil is an edaphic habitat). The substrate is characterized by a certain chemical composition which affects organisms. If the substrate is understood as a habitat, then in this case it is a complex of biotic and abiotic factors characteristic of it, to which one or another organism adapts.

Characteristics of temperature as an abiotic environmental factor

Temperature is an environmental factor associated with average kinetic energy movement of particles and expressed in degrees of various scales. The most common is the scale in degrees Celsius (°C), which is based on the amount of expansion of water (the boiling point of water is 100°C). In SI, an absolute temperature scale is adopted, for which the boiling point of water is T kip. water = 373 K.

Very often, temperature is a limiting factor that determines the possibility (impossibility) of living organisms in a particular habitat.

According to the nature of body temperature, all organisms are divided into two groups: poikilothermic (their body temperature depends on the ambient temperature and is almost the same as the ambient temperature) and homoiothermic (their body temperature does not depend on temperature external environment and is more or less constant: if it fluctuates, then within small limits - fractions of a degree).

Poikilotherms are plant organisms, bacteria, viruses, fungi, unicellular animals, as well as animals with relatively low level organizations (fish, arthropods, etc.).

Homeotherms include birds and mammals, including humans. A constant body temperature reduces the dependence of organisms on the temperature of the external environment, makes it possible to settle in more ecological niches both in latitudinal and vertical distribution on the planet. However, in addition to homoiothermy, organisms develop adaptations to overcome the effects of low temperatures.

According to the nature of the transfer of low temperatures, plants are divided into heat-loving and cold-resistant. The heat-loving plants include plants of the south (bananas, palm trees, southern varieties of apple trees, pears, peaches, grapes, etc.). Cold-resistant plants include medium and northern latitudes, as well as plants growing high in the mountains (for example, mosses, lichens, pine, spruce, fir, rye, etc.). AT middle lane In Russia, varieties of frost-resistant fruit trees are grown, which are specially bred by breeders. The first great successes in this area were achieved by I. V. Michurin and other folk breeders.

The rate of the body's reaction to the temperature factor (for individual organisms) is often narrow, i.e. a particular organism can function normally in a fairly narrow temperature range. Thus, marine vertebrates die when the temperature rises to 30-32°C. But for living matter as a whole, the boundaries of the temperature effect at which life is preserved are very wide. So, in California, a species of fish lives in hot springs, functioning normally at a temperature of 52 ° C, and heat-resistant bacteria that live in geysers can withstand temperatures up to 80 ° C (this is the “normal” temperature for them). In glaciers at a temperature of -44 ° C, some live, etc.

The role of temperature as an environmental factor is that it affects the metabolism: when low temperatures the rate of bioorganic reactions greatly slows down, and at high rates it increases significantly, which leads to an imbalance in the course of biochemical processes, and this causes various diseases and sometimes death.

The effect of temperature on plant organisms

Temperature is not only a factor determining the possibility of plant habitation in a particular area, but for some plants it affects the process of their development. Thus, winter varieties of wheat and rye, which did not undergo the process of “vernalization” (low temperatures) during germination, do not produce seeds when they grow in the most favorable conditions.

Plants have various adaptations to withstand exposure to low temperatures.

1. In winter period the cytoplasm loses water and accumulates substances that have the effect of "antifreeze" (these are monosaccharides, glycerin and other substances) - concentrated solutions such substances freeze only at low temperatures.

2. The transition of plants to a stage (phase) resistant to low temperatures - the stage of spores, seeds, tubers, bulbs, rhizomes, root crops, etc. Woody and shrubby forms of plants shed their leaves, the stems are covered with cork, which has high thermal insulation properties, and antifreeze substances accumulate in living cells.

The effect of temperature on animal organisms

Temperature affects poikilothermic and homeothermic animals differently.

Poikilothermic animals are active only during the period of optimal temperatures for their vital activity. During the period of low temperatures, they fall into hibernation (amphibians, reptiles, arthropods, etc.). Some insects overwinter either as eggs or as pupae. The hibernation of an organism is characterized by a state of anabiosis, in which metabolic processes are very strongly inhibited and the body can long time go without food. Poikilothermic animals can hibernate under the influence of high temperatures. So, animals in the lower latitudes in the hot time of the day are in holes, and the period of their active life falls on the early morning or late evening (or they are nocturnal).

Animal organisms fall into hibernation not only due to the influence of temperature, but also due to other factors. So, a bear (a homeothermic animal) hibernates in winter due to a lack of food.

homeothermic animals in lesser degree in their vital activity depend on temperature, but the temperature affects them in terms of the presence (absence) of food supply. These animals have the following adaptations to overcome the effects of low temperatures:

1) animals move from colder to warmer regions (bird migration, mammal migration);

2) change the nature of the cover (summer fur or plumage is replaced by a thicker winter one; accumulate large layer fat - wild pigs, seals, etc.);

3) hibernate (for example, a bear).

Homeothermic animals have adaptations to reduce exposure to temperatures (both high and low). So, a person has sweat glands that change the nature of secretion when elevated temperatures(the amount of secretion increases), the lumen changes blood vessels in the skin (at low temperatures it decreases, and at high temperatures it increases), etc.

Radiation as an abiotic factor

Both in plant life and in animal life huge role various radiations play, which either enter the planet from the outside (solar rays), or stand out from the bowels of the Earth. Here we consider mainly solar radiation.

Solar radiation is heterogeneous and consists of electromagnetic waves different lengths and therefore have different energies. The Earth's surface is reached by both visible and non-visible rays. visible spectrum. The invisible spectrum includes infrared and ultraviolet rays, while the visible spectrum has seven of the most distinguishable rays (from red to violet). radiation quanta increases from infrared to ultraviolet (i.e., ultraviolet rays contain quanta of the shortest waves and the highest energy).

The sun's rays have several ecologically important functions:

1) thanks sunbeams a certain temperature regime is realized on the Earth's surface, which has a latitudinal and vertical zonal character;

In the absence of human influence, the composition of the air, however, may differ depending on the height above sea level (with height, the content of oxygen and carbon dioxide decreases, since these gases are heavier than nitrogen). The air of coastal areas is enriched with water vapor, which contains sea ​​salts in a dissolved state. The air of the forest differs from the air of the fields by impurities of compounds secreted by various plants (for example, the air pine forest contains a large number of resinous substances and esters that kill pathogens, so this air is curative for tuberculosis patients).

Climate is the most important complex abiotic factor.

Climate is a cumulative abiotic factor that includes a certain composition and level solar radiation, the level of temperature and humidity effects associated with it, and a certain wind regime. The climate also depends on the nature of the vegetation growing in a given area, and on the terrain.

On Earth, there is a certain latitudinal and vertical climatic zonality. There are humid tropical, subtropical, sharply continental and other types of climate.

Repeat information about various types climate according to the textbook physical geography. Consider the climate of the area where you live.

Climate as a cumulative factor forms one or another type of vegetation (flora) and a closely related type of fauna. Big influence human settlements affect the climate. Climate big cities different from the climate of suburban areas.

Compare the temperature regime of the city where you live and the temperature regime of the area where the city is located.

As a rule, the temperature in the city (especially in the center) is always higher than in the region.

Microclimate is closely related to climate. The reason for the emergence of the microclimate is the differences in the relief in a given territory, the presence of water bodies, which leads to a change in conditions in different territories of a given territory. climate zone. Even in a relatively small area of ​​a summer cottage, in some parts of it, there may be various conditions for plant growth due to different conditions lighting.

abiotic factors. Temperature

Abiotic factors- all components and phenomena of inanimate nature.

Temperature refers to climatic abiotic environmental factors. Most organisms are adapted to a rather narrow temperature range, since the activity of cellular enzymes lies in the range from 10 to 40 ° C, at low temperatures the reactions are slow.

There are animal organisms:

• with constant body temperature warm-blooded, or homoiothermic);
• with fluctuating body temperature cold-blooded, or poikilothermic).

Plants and animals have special adaptationspadding to adapt to temperature fluctuations.

Organisms whose body temperature changes depending on the ambient temperature (plants, invertebrates, fish, amphibians and reptiles) have various adaptations to maintain life. Such animals are called cold-blooded, or poikilothermic. The absence of a thermoregulatory mechanism is due to poor development nervous system, low metabolic rate and lack of closed system circulation.

The body temperature of poikilothermic animals is only 1–2 °C higher than or equal to the ambient temperature, but it can increase as a result of the absorption of solar heat (snakes, lizards) or muscle work (flying insects, fast-swimming fish). Sharp fluctuations in ambient temperature can lead to death.

With the onset of winter, plants and animals sink into a state of winter dormancy. Their metabolic rate drops sharply. In preparation for winter, a lot of fat and carbohydrates are stored in the tissues of animals, the amount of water in the fiber decreases, sugars and glycerin accumulate, which prevents freezing.

Species with unstable body temperature are able to go into an inactive state when the temperature drops. Slowing down the metabolism in cells greatly increases the resistance of organisms to adverse weather conditions. The transition of animals into a state of stupor, like the transition of plants to a state of rest, allows them to endure winter cold with the least loss, without spending a lot of energy.

To protect organisms from overheating during the hot season, special physiological mechanisms: in plants, the evaporation of moisture through the stomata increases, in animals, the evaporation of water through respiratory system and skin.

In poikilothermic organisms, core body temperature follows changes in environmental temperature. Their metabolic rate goes up and down. Such species are the majority on Earth.

Organisms with a constant body temperature are called warm-blooded, or homeothermic. These include birds and mammals.

The body temperature of such animals is stable, it does not depend on the temperature of the environment, due to the presence of thermoregulation mechanisms. The constancy of body temperature is ensured by the regulation of heat production and heat transfer.

With the threat of overheating of the body, the expansion of skin vessels occurs, sweating and heat transfer increase. When there is a threat of cooling, skin vessels constrict, wool or feathers rise - heat transfer is limited.

With significant changes in outside temperature and abrupt changes heat production temperature internal organs in warm-blooded animals may deviate from usual values from 0.2-0.3 to 1-3 °C.

Sweating is peculiar only to humans, monkeys and equids. In other homoiothermic animals, the most efficient mechanism for heat transfer is heat dyspnea. The ability to increase heat production is most pronounced in birds, rodents and some other animals.

Homeotherms are able to maintain a constant body temperature under any environmental conditions. Their metabolism always goes at a high rate, even if outdoor temperature constantly changing. For example, polar bears in the Arctic or penguins in Antarctica can withstand 50-degree frosts, which is a difference of 87-90 degrees compared to their own temperature.

Adaptations of organisms to different temperature regimes. Both warm-blooded and cold-blooded animals in the process of evolution have developed various adaptations to changing environmental temperature conditions.The main source of thermal energy in organisms with unstable body temperature is external heat.

Overwintered snakes need two to three weeks to bring their metabolism up to a sufficient intensity. Usually snakes crawl out and bask in the sun repeatedly throughout the day, and return to their burrows at night.

With the onset of winter, plants and animals with unstable body temperature fall into a state of winter dormancy. Their metabolic rate is sharply reduced. In preparation for winter, a lot of fats and carbohydrates are stored in the tissues.

In autumn, plants reduce the consumption of substances, storing sugar and starch. Their growth stops, the intensity of all physiological processes, falling leaves. In the first frosts, plants lose a significant amount of water, becoming resistant to frost and going into a state of deep dormancy.

In the hot season, overheating protection mechanisms are activated. In plants, the evaporation of water through the stomata increases, and in animals - through the respiratory system and skin.

If the plants are sufficiently provided with water, the stomata are open day and night. However, in many plants, the stomata are open only during the day in the light, and close at night. In dry, hot weather, the stomata of plants close even during the day, and the release of water vapor from the leaves into the air stops. When they come favorable conditions, the stomata open and the normal vital activity of the plants is restored.

The most perfect thermoregulation is observed in animals with a constant body temperature. Regulation of heat transfer by skin vessels, well developed higher nervous activity allowed birds and mammals to remain active during sudden temperature changes and master almost all habitats.

Complete division of blood into venous and arterial, intensive metabolism, feather or hairline of the body, contributing to the preservation of heat.

Of great importance for warm-blooded animals is not only the ability to thermoregulate, but also adaptive behavior, construction of special shelters and nests.