Habitat. Living conditions

Topic Autecology

Autecology, which studies the relationship of organisms to environmental conditions, is the oldest section of general ecology. Essentially, E. Haeckel understood ecology as autecology. Charles Darwin, the author of the theory of adaptation of organisms to environmental conditions through natural selection, was also an autecologist.

This section of ecology includes the characteristics of environmental factors (factorial ecology) and ways of adaptation (adaptation) of organisms to its various conditions. In the XX century. autecology has been supplemented with new sections on the functional role of organisms in the ecosystem and their life strategies.

Autecology studies the relationship of organisms to environmental conditions at the species level, which is necessary both for the study of populations (this makes it possible to “bracket” those features that are characteristic of all populations of the same species), and for the study of ecosystems, the elements of which are species.

Environment is one of the basic ecological concepts; it is understood as a complex of natural bodies and phenomena with which the organism is in direct or indirect relationship. The term "environment" is widely used. , defined as a set of forces and phenomena of nature, its substance and space, any human activity that is outside the object or subject under consideration and not necessarily in direct contact with it. The concept of environment is identical to the previous one, but implies direct contact with objects or subjects.

They also distinguish natural environment -(a set of natural and man-made factors of animate and inanimate nature, showing the effect of influencing organisms), abiotic environment -(all forces and phenomena of nature, the origin of which is not directly related to the vital activity of living organisms) and biotic environment -(forces and phenomena of nature, owing their origin to the vital activity of living organisms).

Aquatic life environment. This is the most ancient environment in which life arose and evolved for a long time even before the moment when the first organisms appeared on land. According to the composition of the aquatic environment of life, two of its main variants are distinguished: freshwater and marine environments.

More than 70% of the planet's surface is covered with water. However, due to the comparative evenness of the conditions of this environment (“water is always wet”), the diversity of organisms in the aquatic environment is much less than on land. Only every tenth species of the plant kingdom is associated with the aquatic environment, the diversity of aquatic animals is somewhat higher. The general ratio of the number of land/water species is about 1:5.

The density of water is 800 times higher than the density of air. And the pressure on the organisms inhabiting it is also much higher than in terrestrial conditions: for every 10 m of depth, it increases by 1 atm. One of the main directions of adaptation of organisms to life in the aquatic environment is to increase buoyancy by increasing the surface of the body and the formation of tissues and organs containing air. Organisms can hover in water (like representatives of plankton - algae, protozoa, bacteria) or actively move like fish forming nekton. A significant part of the organisms is attached to the bottom surface or moves along it. As already noted, an important factor in the aquatic environment is the current.

The basis of the production of most aquatic ecosystems are autotrophs, using sunlight that breaks through the water column. The possibility of "piercing" this thickness is determined by the transparency of the water. In the clear water of the ocean, depending on the angle of incidence of sunlight, autotrophic life is possible up to a depth of 200 m in the tropics and 50 m in high latitudes (for example, in the seas of the Arctic Ocean). In strongly disturbed freshwater reservoirs, a layer inhabited by autotrophs (it is called photic), may be only a few tens of centimeters.

The red part of the light spectrum is most actively absorbed by water, therefore, as noted, the deep waters of the seas are inhabited by red algae, which are capable of assimilating green light due to additional pigments. The transparency of water is determined by a simple device - the Secchi disk, which is a white-colored circle with a diameter of 20 cm. The degree of water transparency is judged by the depth at which the disk becomes indistinguishable.

The most important characteristic of water is its chemical composition - the content of salts (including nutrients), gases, hydrogen ions (pH). According to the concentration of nutrients, especially phosphorus and nitrogen, water bodies are divided into oligotrophic, mesotrophic and eutrophic. With an increase in the content of nutrients, for example, when a reservoir is polluted with wastewater, the process of eutrophication of aquatic ecosystems occurs.

The oxygen content in water is about 20 times lower than in the atmosphere, and is 6-8 ml/l. It decreases with increasing temperature, as well as in stagnant water bodies in winter, when the water is isolated from the atmosphere by a layer of ice. A decrease in oxygen concentration can cause the death of many inhabitants of aquatic ecosystems, excluding species that are especially resistant to oxygen deficiency, such as crucian carp or tench, which can live even when the oxygen content drops to 0.5 ml/l. The content of carbon dioxide in water, on the contrary, is higher than in the atmosphere. In sea water, it can contain up to 40-50 ml / l, which is about 150 times higher than in the atmosphere. Consumption of carbon dioxide by phytoplankton during intensive photosynthesis does not exceed 0.5 ml/l per day.

The concentration of hydrogen ions in water (pH) can vary within 3.7-7.8. Waters with a pH of 6.45 to 7.3 are considered neutral. As already noted, with a decrease in pH, the biodiversity of organisms inhabiting the aquatic environment rapidly decreases. Crayfish, many types of mollusks die at pH below 6, perch and pike can withstand pH up to 5, eel and char survive when the pH drops to 5-4.4. In more acidic waters, only some species of zooplankton and phytoplankton survive. Acid rains associated with the release of large amounts of sulfur and nitrogen oxides into the atmosphere by industrial enterprises have become the cause of acidification of the waters of lakes in Europe and the United States and a sharp depletion of their biological diversity.

Ground-air environment of life. Air has a much lower density than water. For this reason, the development of the air environment, which occurred much later than the origin of life and its development in the aquatic environment, was accompanied by an increase in the development of mechanical tissues, which allowed organisms to resist the action of the law of universal gravitation and wind (skeleton in vertebrates, chitinous shells in insects, sclerenchyma in plants). In conditions of only air, not a single organism can live permanently, and therefore even the best “flyers” (birds and insects) must periodically descend to the ground. The movement of organisms through the air is possible due to special devices - wings in birds, insects, some species of mammals and even fish, parachutes and wings in seeds, air sacs in coniferous pollen, etc.

Air is a poor conductor of heat, and therefore it was in the air environment on land that endothermic (warm-blooded) animals arose, which are easier to keep warm than ectothermic inhabitants of the aquatic environment. For warm-blooded aquatic animals, including giant whales, the aquatic environment is secondary; the ancestors of these animals once lived on land.

Life in the air required more complex reproductive mechanisms that would eliminate the risk of germ cells drying out (multicellular antheridia and archegonia, and then ovules and ovaries in plants, internal fertilization in animals, eggs with a dense shell in birds, reptiles, amphibians, etc. ).

In general, there are many more opportunities for the formation of various combinations of factors in the ground-air environment than in water. It is in this environment that differences in the climate of different regions (and at different heights above sea level within the same region) are most clearly manifested. Therefore, the diversity of terrestrial organisms is much higher than that of aquatic ones.

Soil life environment. Most of the land is covered with a thin layer (compared to the thickness of the earth's crust) of soil, named by V.I. Vernadsky bioinert body. The soil is a complex multilayer "pie" of horizons with different properties, and the composition and thickness of the "pie" in different zones are different. Zonal (from podzols and gray forest soils to chernozems, chestnut and brown soils) and hydrogenous (from wet-meadow to marsh-peaty) soil series are well known. In the southern regions, soils can also be saline on the surface (alkaline soils and solonchaks) or in depth (solonetzes).

Any soil is a multiphase system, which includes:

1) mineral particles - from the finest silt to sand and gravel;

2) organic matter - from the bodies of just dead animals and dead roots of plants to humus, in which this organic matter has undergone complex chemical processing;

3) the gas (air) phase, the nature of which is largely determined by the physical properties of the soil - its structure and, accordingly, density and porosity. The gas phase of the soil is always enriched in carbon dioxide and water vapor and can be depleted in oxygen, which brings the conditions of life in the soil closer to those of the aquatic environment;

4) water phase. Water in the soil can also be contained in different quantities (from excess to extreme deficiency) and in different qualities, be gravitational - freely moving through capillaries and most accessible to the roots of plants and animal organisms, hygroscopic, which is part of colloidal particles, and gas, t i.e. in the form of steam.

This multi-phase nature of soils makes their environment the most saturated with life. The main biomass of animals, bacteria, fungi is concentrated in soils, it contains the roots of plants that live in the ground-air environment, but extract water from the soil with nutrients and supply organic matter accumulated in the process of photosynthesis in the light to the "dark world" of the soil. Soil is the main "processing shop" of organic matter, up to 90% of the carbon returned to the atmosphere flows through it.

The gigantic diversity of life in the soil includes not only those organisms that live in it constantly - vertebrates (moles), arthropods, bacteria, algae, earthworms, etc., but also those organisms that are associated with it only at the beginning of their "biography" (locusts, many beetles, etc.).

Plant adaptation to some variants of extreme soil conditions (drought, salinity) will be considered in the next lecture.

Tick-borne encephalitis is a disease that affects the human central nervous system. It is caused by a virus, the carriers and keepers of the virus are ixodid ticks. The favorite habitats of ticks are the southern part of the taiga forests throughout the European and Asian parts of Russia.

The modern taxonomy of living organisms is based on the degree of relatedness of organisms. Ecological classifications can be based on a variety of criteria: methods of nutrition, movement, attitudes towards temperature, humidity, free oxygen, etc. The diversity of adaptation to the environment creates the need for multiple classifications.

Among the adaptations of living organisms to the environment, morphological adaptations play a special role. Changes to the greatest extent affect organs that are in direct contact with the external environment. As a result, convergence (convergence) of morphological (external) features in different species is observed, while anatomical and other features change to a lesser extent, reflecting the relationship and origin of the species.

The morphological (morphophysiological) type of adaptation of an animal or plant to certain living conditions and a certain way of life is called life form of an organism. There are a large number of classifications of life forms of plants and animals based on different characteristics. The first classifications were based on the appearance of plants, which determined the landscape of the area. Below is one such classification.

- Trees - perennial plants with lignified aerial parts, pronounced one trunk, not less than 2 m in height.

- Shrubs- perennial plants with woody aerial parts. Unlike trees, they do not have a distinct single trunk; branching starts from the ground itself, so several equivalent trunks are formed.

- Shrubs similar to shrubs, but stunted, not higher than 50 cm.

Subshrubs differ from shrubs in that only the lower parts of the shoots become woody, the upper ones often die off.

- Lianas - plants with climbing, clinging and climbing stems.

- Succulents- perennial plants with succulent stems and leaves containing a supply of water.

- Herbal plants- perennial and annual plants in which the aerial parts die off for the winter (perennials, biennials) or the whole plant dies off (annual plants).

Later classifications were based on the adaptive characteristics of plants to the conditions of existence. Among botanists, the classification of K. Raunkier (1905) is popular according to the position of buds or shoot tips during an unfavorable season in relation to the soil surface and snow cover (Fig. 1). This feature has a deep biological meaning: the protection of meristems intended for continued growth ensures the continued existence of an individual in a rapidly changing environment. According to this system, plants are divided into five groups:

Phanerophytes (P)- trees, shrubs, lianas, epiphytic plants, buds, the renewal of which is high above the soil surface (not lower than 30 cm) and, thanks to scales, resinous secretions, are well protected from freezing and winter desiccation;

Hamefites (Ch) - low plants - shrubs and semi-shrubs; their renewal buds on wintering shoots are located at a height of 20-30 cm above the soil level, which ensures their wintering under the protection of snow cover. These include lingonberries (Vaccinium vitisidaea), blueberries (Vaccinium myrtillus), periwinkle (Vinca minor);

Rice. 1 - Life forms of plants according to Raunkier:

1 - 3 - phanerophytes, 4,5 - hamefites, 6,7 - hemicryptophytes, 8 - 11 - cryptophytes, 12 - terophyte, 13 - seed with germ.

Hemicryptophytes (H)- herbaceous perennials, in which the main part of the above-ground organs dies off, covering the renewal buds located at the soil level. These are nettle (Urtica dioica), medicinal dandelion (Taraxacum officinale), etc.

Cryptophytes(K) - an extensive group of plants in which the buds of renewal and the tops of modified shoots are underground or in another substrate. The group is divided into three subgroups:

a) geophytes, in which wintering buds are located on underground organs (bulbs, rhizomes, roots);

b) helophytes- plants of coastal and swampy habitats, wintering buds of which are located below the bottom of the reservoir. These include: arrowhead (Saggitaria saggitifolia), chastukha (Alisma plantagoaquatica), umbrella susak (Butonus umbellatus);

in) hydrophytes- aquatic plants with floating or submerged leaves. Their renewal buds hibernate at the bottom of the reservoir on perennial rhizomes, such as, for example, in the white water lily (Nymphaea alba) or in the form of specialized buds - turions, as is observed in the duckweed (Lemna minor), pierced-leaved pondweed (Potamogeton perfoliatus).

Therophytes(Th) - annual plants that survive a dry or cold period in the form of seeds or spores, equipped with morphological and physiological adaptations to effectively counteract adverse conditions.

The distribution of the listed groups of plants by climatic zones (in percentage terms) forms their biological spectrum:

Zone P Ch H K Th

Tropical 69(8)* 6 12 5 16

Desert 4 8 1 5 82

Mediterranean 12 6 29 11 42

Moderate 8 6 52 25 9

Arctic 1 22 60 15 2

* The number in brackets shows the distribution of epiphytic plants.

D.N. Kashkarov (1945) classified the life forms of animals according to the nature of movement in different environments.

I. floating forms.

1 Pure water:

a) nekton;

b) plankton;

c) benthos.

2 semi-aquatic:

a) diving

b) non-divers;

c) only getting food from the water.

II. Burrowing forms.

1 Absolute excavators (who spend their whole lives underground).

2 Relative excavations (coming to the surface).

III. ground forms.

1 Non-burrowers:

a) running

b) jumping;

c) crawling.

2 Making holes:

a) running

b) jumping;

c) crawling.

3 Animals rocks.

IV. Tree climbing forms:

a) not descending from the trees;

b) only climbing trees.

V. Air molds:

a) get food in the air;

b) looking for food from the air.

biological rhythms- these are periodically repeating changes in the intensity and nature of biological processes and phenomena. In one form or another, they are inherent in all living organisms and are noted at all levels of organization: from intracellular processes to biospheric ones. Biological rhythms are hereditarily fixed and are the result of natural selection and adaptation of organisms. Rhythms are intraday, daily, seasonal, annual, long-term and centuries-old.

Examples of biological rhythms are: rhythm in cell division, DNA and RNA synthesis, hormone secretion, daily movement of leaves and petals towards the Sun, autumn leaf fall, seasonal lignification of wintering shoots, seasonal migrations of birds and mammals, etc. Biological rhythms are divided into exogenous and endogenous.

Exogenous (external) rhythms arise as a reaction to periodic changes in the environment (change of day and night, seasons, solar activity).

Endogenous (internal) rhythms are generated by the organism itself. The processes of DNA, RNA and protein synthesis, the work of enzymes, cell division, heartbeat, respiration, etc. have rhythm. External influences can shift the phases of these rhythms and change their amplitude. Among endogenous, physiological and ecological rhythms are distinguished.

Physiological rhythms(heartbeat, respiration, the work of the endocrine glands, etc.) support the continuous vital activity of organisms.

Ecological rhythms(daily, annual, tidal, lunar, etc.) arose as an adaptation of living beings to periodic changes in the environment.

Physiological rhythms vary significantly depending on the state of the body, while environmental rhythms are more stable and correspond to external rhythms.

Ecological rhythms are able to adapt to changes in the cyclicity of external conditions, but only within certain limits. Such adjustment is possible due to the fact that during each period there are certain time intervals (potential readiness time) when the body is ready to perceive a signal from the outside, for example, bright light or darkness. If the signal is somewhat late or arrives prematurely, the phase of the rhythm shifts accordingly. Under experimental conditions with constant illumination and temperature, the same mechanism provides a regular phase shift during each period. Therefore, the rhythm period under these conditions usually does not correspond to the natural cycle and gradually diverges in phase with local time.

The endogenous component of the rhythm gives the body the ability to navigate in time and prepare in advance for the upcoming changes in the environment. This is the so-called biological clock of the body. Many living organisms are characterized by circadian and circanian rhythms. Circadian (circadian) rhythms - repetitive changes in the intensity and nature of biological processes and phenomena with a period of 20 to 28 hours. Circanian (near-annual) rhythms - recurring changes in the intensity and nature of biological processes and phenomena with a period of 10 to 13 months. Circadian and circan rhythms are recorded under experimental conditions at constant temperature, illumination, etc.

The physical and psychological states of a person have a rhythmic character. Violation of the established rhythms of life can reduce performance, have an adverse effect on human health. The study of biorhythms is of great importance in the organization of work and leisure of a person, especially in extreme conditions (in polar conditions, in space, when moving quickly to other time zones, etc.).

The mismatch in time between natural and anthropogenic phenomena often leads to the destruction of natural systems. For example, when carrying out too frequent logging.

FINDINGS

1. Thus, the habitat is the immediate environment of the organism, which includes a combination of abiotic and biotic factors of an individual organism or biocenosis as a whole, affecting their growth and development, i.e. it is a part of nature that directly surrounds these living organisms, all that among which they live.

2. In the process of evolution, organisms have mastered 4 habitats: aquatic, soil, terrestrial-air, organismic, and have also developed certain adaptations (adaptations) to each habitat.

3. Among the adaptations of living organisms to the environment, morphological adaptations play a special role. Changes to the greatest extent affect organs that are in direct contact with the external environment. The morphological type of adaptation of an animal or plant to certain living conditions and a certain way of life is called life form of an organism.

4. Periodically repeating changes in the intensity and nature of biological processes and phenomena are biological rhythms. In one form or another, they are inherent in all living organisms and are noted at all levels of organization: from intracellular processes to biospheric ones. Biological rhythms are hereditarily fixed and are the result of natural selection and adaptation of organisms. Rhythms are within daily, daily, seasonal, annual, perennial and centuries-old.

The soil is a loose, thin surface layer of land in contact with the air. Its most important property is fertility, those. ability to ensure the growth and development of plants. Soil is not just a solid body, but a complex three-phase system in which solid particles are surrounded by air and water. It is permeated with cavities filled with a mixture of gases and aqueous solutions, and therefore extremely diverse conditions are formed in it, favorable for the life of many micro- and macro-organisms. In the soil, temperature fluctuations are smoothed compared to the surface layer of air, and the presence of groundwater and the penetration of precipitation create moisture reserves and provide an intermediate moisture regime between the aquatic and terrestrial environments. The soil concentrates reserves of organic and mineral substances supplied by dying vegetation and animal carcasses (Fig. 1.3).

Rice. 1.3.

The soil is heterogeneous in its structure and physico-chemical properties. The heterogeneity of conditions in the soil is most pronounced in the vertical direction. With depth, a number of the most important environmental factors that affect the life of the inhabitants of the soil change dramatically. First of all, this refers to the structure of the soil. Three main horizons are distinguished in it, differing in morphological and chemical properties (Fig. 1.4): 1) the upper humus-accumulative horizon A, in which organic matter accumulates and transforms and from which part of the compounds is carried down by washing water; 2) the intrusion horizon, or illuvial B, where the substances washed out from above settle and are transformed, and 3) the parent rock, or C horizon, the material of which is transformed into soil.

Fluctuations in cutting temperature only on the soil surface. Here they can be even stronger than in the ground layer of air. However, with each centimeter deep, daily and seasonal temperature changes are becoming less and less visible at a depth of 1-1.5 m.

Rice. 1.4.

All these features lead to the fact that, despite the great heterogeneity of environmental conditions in the soil, it acts as a fairly stable environment, especially for mobile organisms. All this determines the high saturation of the soil with life.

The root systems of terrestrial plants are concentrated in the soil. In order for plants to survive, the soil as a habitat must satisfy their need for mineral nutrients, water and oxygen, while pH values ​​\u200b\u200bare important (relative acidity and salinity (salt concentration).

1. Mineral nutrients and the ability of the soil to retain them. Plants need the following mineral nutrients to feed their plants. (biogens), like nitrates (N0 3), phosphates ( Р0 3 4),

potassium ( To+) and calcium ( Ca 2+). With the exception of nitrogen compounds, which are formed from atmospheric N 2 in the circulation of this element, all mineral biogens are initially included in the chemical composition of rocks along with "non-nutritional" elements such as silicon, aluminum and oxygen. However, these biogens are inaccessible to plants as long as they are fixed in the rock structure. In order for biogen ions to pass into a less bound state or into an aqueous solution, the rock must be destroyed. The breed they call maternal, destroyed by natural weathering. When nutrient ions are released, they become available to plants. Being the original source of nutrients, weathering is still too slow a process to ensure the normal development of plants. In natural ecosystems, the main source of nutrients is decomposing detritus and metabolic waste of animals, i.e. nutrient cycle.

In agroecosystems, there is an inevitable removal of nutrients with the harvested crop, since they are part of the plant material. Their stock is regularly replenished by adding fertilizers.

• 2. Water and water holding capacity. Moisture in the soil is present in various states:
• 1) bound (hygroscopic and film) is firmly held by the surface of soil particles;
• 2) capillary occupies small pores and can move along them in different directions;
• 3) gravity fills larger voids and slowly seeps down under the influence of gravity;
• 4) vapor is contained in the soil air.

If there is too much gravitational moisture, then the regime of the soil is close to the regime of water bodies. In dry soil, only bound water remains, and conditions approach those on the ground. However, even in the driest soils, the air is wetter than the ground, so the inhabitants of the soil are much less susceptible to the threat of drying out than on the surface.

In the leaves of plants there are thin pores through which carbon dioxide (CO 2) is absorbed and oxygen (0 2) is released during photosynthesis. However, they also let water vapor from wet cells inside the leaf out. To compensate for this loss of water vapor, leaves called transpiration at least 99% of all water absorbed by the plant is needed; less than 1% is spent on photosynthesis. If there is not enough water to make up for transpiration losses, the plant will wilt.

Obviously, if rainwater runs off the surface of the soil instead of being absorbed, it will not be useful. Therefore it is very important infiltration, those. absorption of water from the soil surface. Since the roots of most plants do not penetrate very deeply into it, water that seeps deeper than a few centimeters (and for small plants, much less depth) becomes inaccessible. Therefore, between rains, plants depend on the water supply held by the surface layer of the soil, like a sponge. This stock is called soil water holding capacity. Even with infrequent rainfall, soils with good water-holding capacity can store enough moisture to support plant life during a fairly long dry period.

Finally, the water supply in the soil is reduced not only as a result of its use by plants, but also due to evaporation from the soil surface.

So, soil with good infiltration and water-holding capacity and cover that reduces water loss from evaporation is ideal.

3. oxygen and aeration. In order to grow and absorb nutrients, roots require energy generated from the oxidation of glucose during cellular respiration. This consumes oxygen and produces carbon dioxide as a waste product. Therefore, ensuring the diffusion (passive movement) of oxygen from the atmosphere into the soil and the reverse movement of carbon dioxide is another important feature of the soil environment. He's called aeration. Usually, aeration is hampered by two circumstances that lead to a slowdown in the growth or death of plants: soil compaction and saturation with water. Seal called the convergence of soil particles between themselves, in which the air space between them becomes too limited for diffusion to occur. Water saturation - the result of overwatering.

The loss of water by the plant during transpiration must be compensated by the reserves of capillary water in the soil. This reserve depends not only on the abundance and frequency of precipitation, but also on the ability of the soil to absorb and retain water, as well as on direct evaporation from its surface when the entire space between soil particles is filled with water. This can be called "flooding" of plants.

The respiration of plant roots is the absorption of oxygen from the environment and the release of carbon dioxide into it. In turn, these gases must be able to diffuse between soil particles.

• 4. Relative acidity (pH). Most plants and animals require a near-neutral pH of 7.0; in most natural habitats, such conditions are observed.
• 5. Salt and osmotic pressure. For normal life, the cells of a living organism must contain a certain amount of water, i.e. require water balance. However, they themselves are not able to actively pump or pump out water. Their water balance is regulated by the ratio - the concentration of salts on the outer and inner sides of the cell membrane. Water molecules are attracted to salt ions. The cell membrane prevents the passage of ions, and water quickly moves through it in the direction of their greater concentration. This phenomenon is called osmosis.

Cells control their water balance by regulating their internal salt concentration, and water flows in and out by osmosis. If the salt concentration outside the cell is too high, water cannot be absorbed. Moreover, under the action of osmosis, it will be pulled out of the cell, which will lead to dehydration and death of the plant. Highly saline soils are practically lifeless deserts.

Soil dwellers. The heterogeneity of the soil leads to the fact that for organisms of different sizes it acts as a different environment.

For small soil animals, which are united under the name microfauna(protozoa, rotifers, tardigrades, nematodes, etc.), the soil is a system of micro-reservoirs. Essentially, they are aquatic organisms. They live in soil pores filled with gravitational or capillary water, and part of their life can, like microorganisms, be in an adsorbed state on the surface of particles in thin layers of film moisture. Many of these species live in ordinary water bodies. However, soil forms are much smaller than freshwater ones, and, in addition, getting into unfavorable environmental conditions, they release a dense shell on the surface of their body - cyst(lat. cista - box), protecting them from drying out, exposure to harmful substances, etc. At the same time, physiological processes slow down, animals become immobile, take a rounded shape, stop eating, and the body falls into a state of latent life (an encysted state). If the encysted individual again finds itself in favorable conditions, excystation occurs; the animal leaves the cyst, turns into a vegetative form and resumes active life.

For air-breathers of slightly larger animals, the soil appears as a system of shallow caves. Such animals are grouped under the name mesofauna. The sizes of representatives of the soil mesofauna range from tenths to 2-3 mm. This group includes mainly arthropods: numerous groups of ticks, primary wingless insects (for example, two-tailed insects), small species of winged insects, symphyla centipedes, etc.

Larger soil animals, with body sizes from 2 to 20 mm, are called representatives macro fauna. These are insect larvae, centipedes, enchytreids, earthworms, etc. For them, the soil is a dense medium that provides significant mechanical resistance when moving.

Megafauna soils are large excavations, mainly from among mammals. A number of species spend their whole lives in the soil (mole rats, mole voles, marsupial moles of Australia, etc.). They make whole systems of passages and holes in the soil. The appearance and anatomical features of these animals reflect their adaptability to a burrowing underground lifestyle. They have underdeveloped eyes, a compact, valky body with a short neck, short thick fur, strong digging limbs with strong claws.

In addition to the permanent inhabitants of the soil, a large ecological group can be distinguished among large animals. burrow dwellers(ground squirrels, marmots, jerboas, rabbits, badgers, etc.). They feed on the surface, but breed, hibernate, rest, and escape danger in the soil.

For a number of ecological features, the soil is an intermediate medium between water and land. The soil is brought closer to the aquatic environment by its temperature regime, the reduced oxygen content in the soil air, its saturation with water vapor and the presence of water in other forms, the presence of salts and organic substances in soil solutions, and the ability to move in three dimensions.

The presence of soil air, the threat of desiccation in the upper horizons, and rather sharp changes in the temperature regime of the surface layers bring the soil closer to the air environment.

The intermediate ecological properties of the soil as a habitat for animals suggest that the soil played a special role in the evolution of the animal world. For many groups, in particular arthropods, the soil served as a medium through which the originally aquatic inhabitants could switch to a terrestrial way of life and conquer the land. This path of evolution of arthropods was proved by the works of M.S. Gilyarov (1912-1985).

Table 1.1 provides a comparative description of abiotic environments and adaptation of living organisms to them.

Characteristics of abiotic environments and adaptation of living organisms to them

Table 1.1

Questions and tasks for self-control

• 1. List the structural elements of the soil.
• 2. What characteristic features of the soil as a habitat do you know?
• 3. What elements and compounds are biogens?
• 4. Conduct a comparative analysis of aquatic, soil and terrestrial-air habitats.

Habitat

This term has other meanings, see Habitat (meanings).

Habitat- this is a part of nature that surrounds living organisms and has a direct or indirect effect on them. From the environment, organisms receive everything necessary for life and excrete metabolic products into it. The environment of each organism is composed of many elements of inorganic and organic nature and elements introduced by man and his production activities. At the same time, some elements may be partially or completely indifferent to the body, others are necessary, and still others have a negative effect.

Untouched by man habitat for many plants and animals

There are natural and artificial (man-made) habitats. Natural habitats are mainly divided into land-air, soil, water and intraorganism. Individual properties and elements of the environment that affect organisms are called environmental factors. All environmental factors can be divided into three large groups:

• Abiotic factors are a set of conditions of the inorganic environment that affect the body. (Light, temperature, wind, air, pressure, humidity, etc.) For example: the accumulation of toxic and chemical elements in the soil, the drying up of water bodies during a drought, an increase in daylight hours, intense ultraviolet radiation.
• Biotic factors are a set of influences of the vital activity of some organisms on others. (Influence of plants and animals on other members of the biogeocenosis) For example: soil destruction by wild boars and moles, a decrease in the number of squirrels in lean years.
• Anthropogenic (anthropic) factors are all forms of activity of human society that change nature as the habitat of living organisms or directly affect their life. The allocation of anthropogenic factors into a separate group is due to the fact that at present the fate of the vegetation cover of the Earth and all currently existing species of organisms is practically in the hands of human society.

It is also possible to single out the following components of the environment: natural bodies of the environment, hydro-environment, air space of the environment, anthropogenic bodies, the field of radiation and gravitation of the environment.

see also

Literature

Afanasiev V. G. The world of the living. Consistency, evolution and management. - M: Ed. polit. l-ry, 1986.

Wikimedia Foundation. 2010 .

See what "Habitat" is in other dictionaries:

All bodies and phenomena with which the organism is in direct or indirect relationship. The habitat directly or indirectly affects the state, development and reproduction of individual organisms and populations. Distinguish between abiotic, biotic and ... ... Glossary of business terms

Human (habitat) is a set of objects, phenomena and factors of the environment (natural and artificial) that determines the conditions of human life. (See: Federal Law 52 FZ. On sanitary and epidemiological well-being ... ... Construction dictionary

The set of specific abiotic and biotic conditions in which a given individual, population, or species lives. (see ABIOTIC ENVIRONMENT, BIOTIC ENVIRONMENT). .(Source: "Biological Encyclopedic Dictionary." Editor-in-Chief M. S. Gilyarov; Ed.: A. A ... Biological encyclopedic dictionary

HABITAT- see Environment. Ecological encyclopedic dictionary. Chisinau: Main edition of the Moldavian Soviet Encyclopedia. I.I. Grandpa. 1989... Ecological dictionary

habitat- A piece of land or a body of water occupied by an organism or its population and possessing the habitat conditions necessary for their existence, including living and inanimate nature. Syn.: habitat; ecotope … Geography Dictionary

- "HABITAT", USSR, Lentelefilm, 1987, color, 75 min. Detective. According to the story by S. Vysotsky. The story of the theft of valuable documents from the historical archive. Cast: Pyotr Velyaminov (see VELIAMINOV Petr Sergeevich), Valery Ivchenko (see IVCHENKO ... ... Cinema Encyclopedia

The complex of all biotic and abiotic conditions in which a given organism lives (or lived), population, biocenosis, etc. Geological Dictionary: in 2 volumes. M.: Nedra. Edited by K. N. Paffengolts et al. 1978 ... Geological Encyclopedia

Habitat- for a person, this is the planet Earth with its specific features, in other places he no longer lives, but can only be. The habitat provides a person with EVERYTHING necessary for his existence as a species: the vital activity of an individual ... ... Theoretical aspects and foundations of the ecological problem: interpreter of words and idiomatic expressions

Environment [habitat]. The set of biotic and abiotic conditions in which a given organism, population, etc. lives. (

The environments (habitats) in which organisms live are different. There are four habitats - ground-air, water, soil and organismic (bodies of other organisms).

Water environment associated with water bodies: oceans, seas, rivers, lakes, etc. The waters in them are different, somewhere stagnant, somewhere with fairly strong currents, salty and fresh. Many waters lack oxygen and sunlight. With depth comes twilight, and after 200 m of depth there is no light at all.

Therefore, plants in water can grow only at a shallow depth, where light still penetrates. The temperature in the aquatic environment does not change so dramatically throughout the year and day. There is no negative water temperature, so even in the coldest places it is +4 °C.

Most aquatic plants are algae. However, among aquatic plants there are also higher plants.

AT ground-air habitat the vast majority of plants and almost all higher plants grow. Land plants form forests and meadows, steppes and tundras and other plant communities. The features of the ground-air environment are a large amount of air and light, the presence of wind, in many places a strong fluctuation in temperature and humidity depending on the time of year and day.

The ground-air environment is very diverse. Plants are adapted to certain environmental conditions. Some grow in well-lit areas, others in shaded areas. Some plants do not tolerate cold and live only in warm latitudes, while others are adapted to seasonal temperature fluctuations. Because of this variety of environments, plants in the ground-air environment are distinguished by many different forms.

soil habitat located in the soil - the upper fertile layer of the earth's crust. The soil is formed as a mixture of particles of decayed rocks and the remains of living organisms (humus). There is almost no light here, so only small algae can live in the soil. However, there are seeds and spores of plants, as well as roots. The soil habitat is inhabited mainly by bacteria, animals and fungi.

Plants can only live in the environments to which they are adapted. If you move the plant to another environment, it may die.

Therefore, when a person grows cultivated plants, he creates the necessary conditions for their normal growth and development - watering them, fertilizing the soil, and eliminating pests. Wild plants are adapted to specific environmental conditions.

Lesson on knowledge of the world for grade 3 "Plant habitat"

The Republic of Kazakhstan. Zhambyl region, Kordai district

Sortobe village, secondary school No. 48

primary school teacher Sofian Iskharovna Machinchin

Subject : Plant habitat

Goals : deepen the concept of plant diversity, learn to distinguish them; explain the features of the structure of plants and their adaptations to the environment in different parts of the Earth, develop cognitive interest, observation, attention, promote the education of cooperation, independence, responsible attitude for behavior in nature, love for the Motherland.

Type lesson: a lesson in the integrated application of knowledge

View lesson: lesson - study

Methods : verbal, practical, visual, self-organization, reproductive

Equipment : plant samples, presentation for the lesson, support schemes

move lesson:

1. Org. moment

Hello guys!

What is the mood?In

Is everyone of this opinion?All without exception.

Maybe you are already tired?We didn't take them with us!

- Can we lie down and rest?Let's start the lesson!

Everyone sat down at the desks

looked at each other

Looking at the guests

Smile quickly.

2. Message topic and purpose

Collect the word that crumbled - RESAD (The word "WEDNESDAY" appears on the board)

What associations arise?

How can the word "Environment" be related to the section "Variety of Plants"?

Today we have a lesson - research. The topic of our lesson is “Plant habitat» (slide) + Topic opens on the board

Object of study (support scheme)is what is being considered.

What are we looking at in this section?

Plants will be our object of study.

Subject of study (support scheme) - the problem that we should study in the lesson

And the subject of today's lesson is “ Plant Habitat". We will explore how plants adapt to their habitat,with the characteristics of plants depending on their habitat

During the study, it is put forwardhypothesis: (support scheme)- assumption: How does the habitat affect the structural features of plants

3. Checking homework

We are finishing the Plant Diversity section. What have we learned from this section?

The test includes questions from the topics covered.

1. Test by variants (different levels)

Option 1 (low motivation)

Plant Diversity Test

1. Which group lists only trees?

a) lilac, poplar, pine

b) birch, maple, oak

c) clover, aspen, spruce

2. Choose from the listed moisture-loving plant:

a) saxaul b) Ivan-tea c) spurge

3. Which of the following plants is annual?

a) pine b) carrot c) wheat

4. A light-loving plant is:

a) spruce b) pine c) lily of the valley

5. Larch is a plant:

a) flowering b) fern c) coniferous

Option 2 (high motivation)

Plant Diversity Test

1. The simplest plants in terms of structure?

2. The most complex plants in their structure:

a) ferns b) algae c) flowering d) mosses

3. What are the names of plants that are not adapted to existence without human intervention?

a) cultivated b) perennial c) wild d) noble

4. Tomato, pepper, cucumber, eggplant are plants:

a) cold-resistant b) drought-resistant c) heat-loving d) shade-tolerant

5. What unites this group of plants: oak, birch, spruce?

a) these are shrubs b) these are trees c) these are all photophilous plants d) these are biennials

Oral check

2. Frontal survey

What groups of plants do you know? (Algae, mosses, ferns, conifers, flowers)

Tell us about these groups of plants.

Seaweed. The word algae comes from two words: water and grow. So algae are basically aquatic plants. There are a lot of algae on Earth. Among them there are giants up to 40 meters long. They live in the seas and oceans. By color, algae are green, blue-green, brown and red. They enrich the water with oxygen and purify it from putrefactive bacteria. Algae is also used for medicinal purposes. Iodine, potassium are obtained from them, tablets are produced. (slide)

Mosses. Mosses appeared on Earth more than 350 million years ago. These are low-growing plants, no more than a few centimeters in height. They have small, root-like endings (not true roots) that trail along the ground. Most mosses prefer moist, shady places. Many mosses look like real sponges. They are able to absorb water. If you pick up moss, squeeze it, then a lot of water will flow out of it. From the mosses that form in the swamps, peat is obtained - a very valuable fertilizer and fuel. (slide)

ferns. Ferns are among the most ancient plants. They are distributed all over the globe. But most of them are in moist forests. They can grow both on soil and on tree trunks. Some ferns grow high in the mountains. Others cling to cracks in the rocks. Even in deserts there are ferns. Ferns never bloom. Ferns do not have seeds. They reproduce by spores. You can also grow a fern at home. Fern is a moisture-loving and shade-tolerant plant. Regular watering and frequent spraying make a beautiful houseplant. (slide)

Coniferous. Spruce, pine, fir, cedar, juniper, larch are coniferous plants, seeds are formed in cones. Seeds of coniferous plants are in cones protecting them. On one of the dry days, the scales of the cones open, releasing the ripened seeds. Conifers are evergreen trees. They retain needles in the winter. Pine needles last 2-3 years, and spruce needles last from five to seven years. Among the conifers, there is only one tree that sheds its needles for the winter, and in the spring they form new ones. This is larch. Coniferous plants have needles instead of leaves. (slide)

Flowering. The most common on Earth are flowering plants.They have root, stem, leaves, flowers, fruit with seeds. Flowering plants are the most extensive division of the plant world. Botanists count more than 250 thousand species of plants. The value of flowering plants for humans is much greater. All cultivated plants that are bred by man are representatives of this department. They grow everywhere - in the forest, in the meadow, in the reservoir, in the desert, in the mountains. (slide)

And in appearance, how can plants be divided? (Trees, shrubs, herbs)

Why can't plants live without sunlight? (Because the sun is a source of energy. It gives warmth to all living things.)

What types of plants according to growing conditions do you know? (Moisture-loving and water-loving, drought-resistant, heat-loving, cold-resistant, light-loving, shade-tolerant.)

3. PHYSMINUTE

We'll get some rest

Let's get up, take a deep breath.

The children were walking in the forest

Watching nature.

Looked up at the sun

And the rays warmed them all.

Miracles in our world -

Became small children

And then everyone stood up together -

You have become giants.

We clap together, stomp our feet!

Well we walked

We got down to business again!

4. Work on the topic

Today we will continue to talk about plants, about the habitat of plants.

The topic of our lesson is "Plant Habitat" (slide) - already open

Knowledge update

Plants are part of what nature? (alive)

Prove that plants are part of wildlife?) (slide)

What do plants give us?(slide)

How can you call it in one word?(flora - slide)

Where can plants live?(slide)

Define "environment"

Habitat - this is the place where they live, i.e. grow, plants. The environment has an impact on plants.

What are the necessary conditions for plant life? (slide)

Tell me, in what places on Earth do plants not live (children's answers)

Why don't plants live there? (eternal cold)

reading the text in the textbook page 118

CONCLUSION:Watch the video "Plant Habitat"

Plants on Earth are found everywhere, they form forests, meadows, therefore plants are called the "green clothes of the Earth." Indeed, the green outfit adorns our planet. Plants can be divided into 3 habitats.

3 PLANT HABITAT

WATER GROUND AND AIR soil

Water environment habitat associated with water bodies: oceans, seas, rivers, lakes and others. The waters in them are different, somewhere stagnant, somewhere with fairly strong currents, salty and fresh. Many waters lack oxygen and sunlight. With depth comes twilight, and after 200 meters of depth there is no light at all. Therefore, plants in water can grow only at a shallow depth, where light still penetrates. Most aquatic plants are algae. However, among aquatic plants there are also higher plants. (slide)

In ground-air habitat the vast majority of plants and almost all higher plants grow. Land plants form forests and meadows, steppes and tundras and other plant communities. The features of the ground-air environment are a large amount of air and light, the presence of wind, in many places a strong fluctuation in temperature and humidity depending on the time of year and day. The ground-air environment is very diverse. Plants are adapted to certain environmental conditions. Some grow in well-lit areas, others in shaded areas. Some plants do not tolerate cold and live only in warm places, others are adapted to seasonal temperature fluctuations.

The soil - This is the surface fertile layer of the earth. This environment was formed from a mixture of mineral substances during the decay of humus rocks as a result of the decomposition of plant and animal remains. Numerous tiny algae live here, seeds and spores of various plants are found, and the roots of land plants are located.

Plants are able to live in the environment to which they are adapted.

What does "aquatic, soil, land-air habitat" mean?(for children - on the memo tables)

How do plants that live in water differ from plants that live in soil? (in aquatic, the roots are thin, small, the leaves are wide, so that moisture evaporates well. In plants whose habitat is soil - the root system is more powerful, the leaves are narrower, so that vice versa - moisture does not evaporate)

You now have to work in pairs - to create a project. You will examine the plant and draw up a passport for this plant.

Who's to say what a passport is?

What is it for?

What information is included in a person's passport?

What do you think can be reflected in the plant passport?

Plant passport (on children's tables)

1.Name

2. External description

3. Lifespan

4. Habitat

5. Endangered

Your subject of study: (slide show)

1 row - lotus2 row - water lily 3 row - lily of the valley

Work in rows (work in pairs - filling out a plant passport) - students read the text.

walnut lotus (slide) Large bright pink flower. Lotus grows in shallow fresh warm waters of ponds and lakes. Perennial. Propagated by seeds that remain viable for more than a thousand years! The roots are used for food. They make flour, starch and even butter. The seeds and roots are also used as medicine. Perennial. Propagated by seeds and pieces of rhizomes.The threat of death: the collection of beautiful flowers, pollution of water bodies.

The water lily is white. (slide)
It grows in ponds with stagnant or slowly flowing water. Its white flowers, similar to an asterisk, are able to predict the weather: they always close before the rain. Every morning they appear on the surface, and at night they plunge into the water. Seeds are adapted to life in the aquatic environment - they have air sacs, so they can float on the surface. Lives 3-5 years. Propagated by seeds, pieces of rhizomes.
The threat of death is a person and pollution of water bodies.

May lily of the valley (slide)
Grows in moist soils, loves shade. Flowers in the form of bells bloom for 10-15 days. A perennial plant that reproduces by segments of rhizomes. At the end of flowering, red berries are formed in place of the flowers, which are very poisonous, and the plant itself is used as a medicine.
The threat of death is posed by humans and livestock grazing.

Protection of the project - plant passports - reading the text.

Which of these plants live in our region? (under natural conditions - water lily, lily of the valley; in artificial - lotus)

The plant kingdom is remarkably diverse. It unites more than 350 thousand species of plants and is represented by a wide variety of forms - from a single-celled plant, which can only be seen with a microscope, to trees - groves, covering an area of ​​tens of square meters.

Game "Get Me" (from the external description, guess which plant we are talking about)

This cold-resistant herbaceous plant meets the very first spring, even the snow has not yet melted. Soil habitat. Listed in the Red Book of the Republic of Kazakhstan

- Why do you think this plant is listed in the Red Book?(snowdrop slide)

The habitat of this plant is soil. This thorny perennial shrub gets its name from the sharp thorns that will cause trouble for anyone who thoughtlessly wants to get to know this handsome man. At the beginning of summer, it is decorated with fragrant flowers that resemble a rose.(rosehip slide)

- What else do you know about this plant?(useful medicinal plant)

- Tall perennial plant.Aquatic habitat. Panicle blooms. It was once used in construction as a cheap material. Plants actively grow, which clogs reservoirs and leads to their chopping. Dried plants often cause a fire.(bulrush -slide)

What do you think about the benefits of this plant?(Many animals of the reservoir breed offspring there and hide from enemies for some time)

5. Homework: read additional material, prepare a retelling message

1 option "Plants of the desert"

2 option "Plants of the steppes"

6. Fixing. Lesson summary

What object was studied in the lesson?

The subject of our study?

What is the habitat of plants?

How does the structure of a plant depend on its environment?