In the land-air environment, temperature has a particularly great influence on organisms. Therefore, the inhabitants of cold and hot regions of the Earth have developed various adaptations to conserve heat or, conversely, to release its excess.
Give some examples.
The temperature of the plant due to heating by the sun's rays can be higher than the temperature of the surrounding air and soil. With strong evaporation, the temperature of the plant becomes lower than the air temperature. Evaporation through stomata is a plant-regulated process. As the air temperature rises, it intensifies if the required amount of water can be quickly supplied to the leaves. This saves the plant from overheating, lowering its temperature by 4-6, and sometimes by 10-15 °C.
When muscles contract, significantly more thermal energy is released than during the functioning of any other organs and tissues. The more powerful and active the muscles, the more heat the animal can generate. Compared to plants, animals have more varied capabilities to regulate, permanently or temporarily, their own body temperature.
By changing the position, the animal can increase or decrease the heating of the body due to solar radiation. For example, the desert locust exposes the wide lateral surface of its body to the sun's rays in the cool morning hours, and the narrow dorsal surface at midday. In extreme heat, animals hide in the shade and hide in burrows. In deserts during the day, for example, some species of lizards and snakes climb bushes, avoiding contact with the hot surface of the soil. By winter, many animals seek shelter, where the temperature course is more smooth compared to open habitats. Even more complex are the forms of behavior of social insects: bees, ants, termites, which build nests with a well-regulated temperature inside them, almost constant during the period of insect activity.
The thick fur of mammals, the feather and especially downy cover of birds make it possible to maintain a layer of air around the body with a temperature close to the body temperature of the animal, and thereby reduce heat radiation during external environment. Heat transfer is regulated by the inclination of hair and feathers, seasonal changes in fur and plumage. The exceptionally warm winter fur of Arctic animals allows them to survive in the cold without increasing their metabolism and reduces the need for food.
Name the desert inhabitants you know.
In the deserts of Central Asia, a small shrub is saxaul. In America - cacti, in Africa - milkweed. Animal world not rich. Reptiles predominate - snakes, monitor lizards. There are scorpions, few mammals (camels).
1. Continue filling out the table “Habitats of living organisms” (see homework for § 42).
A distinctive feature of the ground-air environment is the presence of air (a mixture of various gases) in it.
Air has a low density, so it cannot serve as a support for organisms (with the exception of flying ones). It is the low density of air that determines its insignificant resistance when moving organisms along the soil surface. At the same time, it makes it difficult for them to move in the vertical direction. Low air density also causes low pressure on land (760 mm Hg = 1 atm). Air is less likely to block sunlight from entering than water. It has higher transparency than water.
The gas composition of the air is constant (you know this from your geography course). Oxygen and carbon dioxide, as a rule, are not limiting factors. Water vapor and various pollutants are present as impurities in the air.
Over the last century, as a result economic activity humans, the content of various pollutants in the atmosphere has sharply increased. Among them, the most dangerous are: nitrogen and sulfur oxides, ammonia, formaldehyde, heavy metals, hydrocarbons, etc. Currently living organisms are practically not adapted to them. For this reason, air pollution is a serious global environmental problem. To solve it, it is necessary to implement environmental protection measures at the level of all states of the Earth.
Air masses move in horizontal and vertical directions. This leads to the appearance of such an environmental factor as wind. Wind can cause the movement of sand in deserts (sandstorms). It is capable of blowing away soil particles on any terrain, reducing land fertility (wind erosion). Wind has a mechanical effect on plants. It is capable of causing windfalls (upending trees with roots), windbreaks (fractures of tree trunks), and deformation of tree crowns. The movement of air masses significantly affects the distribution of precipitation and temperature conditions in the ground-air environment.
Water regime of the ground-air environment
From your geography course, you know that the land-air environment can be either extremely saturated with moisture (tropics) or very poor in it (deserts). Precipitation is distributed unevenly both by season and by geographical areas. Humidity in the environment fluctuates over a wide range. It is the main limiting factor for living organisms.
Temperature regime of the ground-air environment
Temperature in the ground-air environment has daily and seasonal periodicity. Organisms have adapted to it since the emergence of life on land. Therefore, temperature is less likely than humidity to act as a limiting factor.
Adaptation of plants and animals to life in the ground-air environment
When plants reached land, they developed tissues. You studied the structure of plant tissues in the 7th grade biology course. Due to the fact that air cannot serve as a reliable support, plants developed mechanical tissues (wood and bast fibers). A wide range of changes in climatic factors caused the formation of dense integumentary tissues - periderm, crust. Thanks to the mobility of air (wind), plants have developed adaptations for pollination, distribution of spores, fruits and seeds.
The life of animals suspended in the air is impossible due to its low density. Many of the species (insects, birds) have adapted to active flight and can stay in the air for a long time. But their reproduction occurs on the soil surface.
The movement of air masses in horizontal and vertical directions is used by some small organisms for passive dispersal. Protists, spiders, and insects settle in this way. Low air density caused the improvement of the external (arthropods) and internal (vertebrates) skeletons in animals during the evolution. For the same reason, there is a limitation on the maximum mass and body size of terrestrial animals. The largest land animal is the elephant (weight up to 5 tons) much smaller than the sea giant - blue whale(up to 150 t). Thanks to the appearance of different types of limbs, mammals were able to populate land areas with different types of relief.
General characteristics of soil as a living environment
Soil is the top layer of the earth's crust that is fertile. It was formed as a result of the interaction of climatic and biological factors with the underlying rock (sand, clay, etc.). The soil is in contact with the air and serves as a support for terrestrial organisms. It is also a source of mineral nutrition for plants. At the same time, soil is a living environment for many species of organisms. The soil is characterized by the following properties: density, humidity, temperature, aeration (air supply), environmental reaction (pH), salinity.
Soil density increases with depth. Humidity, temperature and soil aeration are closely interrelated and interdependent. Temperature fluctuations in the soil are smoothed out compared to the surface air and are no longer traceable at a depth of 1-1.5 m. Well-moistened soils warm up slowly and cool down slowly. An increase in soil humidity and temperature worsens its aeration, and vice versa. The hydrothermal regime of the soil and its aeration depend on the structure of the soil. Clay soils retain moisture better than sandy soils. But they aerate worse and warm up worse. According to the reaction of the environment, soils are divided into three types: acidic (pH< 7,0), нейтральные (рН ≈ 7,0) и щелочные (рН > 7,0).
Adaptations of plants and animals to life in soil
In the life of plants, soil performs the functions of anchoring, water supply, and a source of mineral nutrition. Concentration nutrients in the soil led to the development of the root system and conductive tissues in plants.
Animals that live in the soil have a number of adaptations. They are characterized by different ways movement in the soil. This can be digging passages and holes, like mole crickets and mole crickets. Earthworms can push soil particles apart and make passages. Insect larvae are able to crawl among soil particles. In this regard, in the process of evolution, appropriate adaptations have been developed. Digging organisms have developed digging limbs. Annelids have a hydrostatic skeleton, while insects and centipedes have claws.
Soil animals have a short, compact body with non-wetting integuments (mammals) or covered with mucus. Life in soil as a habitat has led to atrophy or underdevelopment of the visual organs. The mole's tiny, underdeveloped eyes are often hidden under a fold of skin. To facilitate movement in narrow soil passages, moles' fur has acquired the ability to fold in two directions.
In the terrestrial-air environment, organisms are surrounded by air. It has low humidity, density and pressure, high transparency and oxygen content. Humidity is the main limiting factor. Soil as a living environment is characterized by high density, a certain hydrothermal regime, and aeration. Plants and animals have developed various adaptations to life in ground-air and soil environments.
Read also:
|
General characteristics. In the course of evolution, the land-air environment was mastered much later than the aquatic environment. Life on land required adaptations that became possible only with a relatively high level of organization in both plants and animals. A feature of the land-air environment of life is that the organisms that live here are surrounded by a gaseous environment characterized by low humidity, density and pressure, and high oxygen content. Typically, animals in this environment move on the soil (hard substrate) and plants take root in it.
In the ground-air environment, the operating environmental factors have a number of characteristic features: higher light intensity compared to other environments, significant temperature fluctuations, changes in humidity depending on geographical location, season and time of day.
In the process of evolution, living organisms of the land-air environment have developed characteristic anatomical, morphological, physiological, behavioral and other adaptations. For example, organs have appeared that provide direct absorption of atmospheric oxygen during respiration (the lungs and trachea of animals, the stomata of plants). Skeletal formations (animal skeleton, mechanical and supporting tissues of plants) that support the body have received strong development
in conditions of low density of the environment. Adaptations have been developed to protect against unfavorable factors, such as the periodicity and rhythm of life cycles, the complex structure of the integument, mechanisms of thermoregulation, etc. A close connection with the soil has formed (animal limbs, plant roots), the mobility of animals in search of food has developed, and air currents have appeared. seeds, fruits and pollen of plants, flying animals.
Low air density determines its low lifting force and insignificant support. All inhabitants of the air are closely connected with the surface of the earth, which serves them for attachment and support. The density of the air environment does not provide high resistance to organisms when they move along the surface of the earth, but it makes it difficult to move vertically. For most organisms, staying in the air is associated only with settling or searching for prey.
The low lifting force of air determines the maximum mass and size of terrestrial organisms. The largest animals living on the surface of the earth are smaller than the giants of the aquatic environment. Large mammals(the size and mass of a modern whale) could not live on land, since they were crushed by their own weight.
Low air density creates little resistance to movement. 75% of all species of land animals are capable of active flight.
Winds increase the release of moisture and heat from animals and plants. When there is wind, heat is easier to bear and frost is more severe, and desiccation and cooling of organisms occurs faster. Wind causes changes in the intensity of transpiration in plants and plays a role in the pollination of anemophilous plants.
Gas composition of air– oxygen – 20.9%, nitrogen – 78.1%, inert gases – 1%, carbon dioxide – 0.03% by volume. Oxygen helps increase metabolism in terrestrial organisms.
Light mode. The amount of radiation reaching the Earth's surface is determined by the geographic latitude of the area, the length of the day, the transparency of the atmosphere and the angle of incidence of the sun's rays. Illumination on the Earth's surface varies widely.
Trees, shrubs, and plant crops shade the area and create a special microclimate, weakening radiation.
Thus, in different habitats, not only the intensity of radiation differs, but also its spectral composition, the duration of illumination of plants, the spatial and temporal distribution of light of different intensities, etc. Accordingly, the adaptations of organisms to life in a terrestrial environment under one or another light regime are also varied. . In relation to light, there are three main groups of plants: light-loving (heliophytes), shade-loving (sciophytes) and shade-tolerant.
Plants of the ground-air environment have developed anatomical, morphological, physiological and other adaptations to various light conditions:
An example of anatomical and morphological adaptations is a change in appearance in different light conditions, for example, the unequal size of leaf blades in plants related in systematic situation, living in different lighting (meadow bell Cumpanula patula and forest - C. trachelium, field violet - Viola arvensis, growing in fields, meadows, edges, and forest violets - V. mirabilis).
In heliophyte plants, the leaves are oriented to reduce the influx of radiation during the most “dangerous” daytime hours. The leaf blades are located vertically or at a large angle to the horizontal plane, so during the day the leaves receive mostly sliding rays.
In shade-tolerant plants, the leaves are arranged so as to receive the maximum amount of incident radiation.
A peculiar form of physiological adaptation during a sharp lack of light is the loss of the plant’s ability to photosynthesize, the transition to heterotrophic nutrition of ready-made inorganic substances. Sometimes such a transition became irreversible due to the loss of chlorophyll by plants, for example, orchids of shady spruce forests (Goodyera repens, Weottia nidus avis), orchids (Monotropa hypopitys).
Physiological adaptations of animals. For the vast majority of terrestrial animals with day and night activity, vision is one of the methods of orientation and is important for searching for prey. Many animal species also have color vision. In this regard, animals, especially victims, developed adaptive features. These include protective, camouflage and warning coloring, protective similarity, mimicry, etc. The appearance of brightly colored flowers of higher plants is also associated with the characteristics of the visual apparatus of pollinators and, ultimately, with the light regime of the environment.
Water mode. Moisture deficiency is one of the most significant features of the land-air environment of life. The evolution of terrestrial organisms took place through adaptation to obtaining and preserving moisture.
()cages (rain, hail, snow), in addition to providing water and creating moisture reserves, often play another ecological role. For example, during heavy rains, the soil does not have time to absorb moisture, the water quickly flows in strong streams and often carries weakly rooted plants, small animals and fertile soil into lakes and rivers.
Hail also has a negative effect on plants and animals. Agricultural crops in individual fields are sometimes completely destroyed by this natural disaster.
The ecological role of snow cover is diverse; for plants whose renewal buds are located in the soil or near its surface, and for many small animals, snow plays the role of a heat-insulating cover, protecting them from low temperatures. winter temperatures. Winter snow cover often prevents large animals from obtaining food and moving, especially when an ice crust forms on the surface. Often during snowy winters, the death of roe deer and wild boars is observed.
Large amounts of snow also have a negative impact on plants. In addition to mechanical damage in the form of snow chips or snow blowers, a thick layer of snow can lead to damping off of plants, and when the snow melts, especially in a long spring, to soaking of plants.
Temperature. Distinctive feature The land-air environment is characterized by a large range of temperature fluctuations. In most land areas, daily and annual temperature ranges are tens of degrees.
Terrestrial plants occupy a zone adjacent to the soil surface, i.e., to the “interface” on which the transition of incident rays from one medium to another occurs, from transparent to opaque. A special thermal regime is created on this surface: during the day there is strong heating due to the absorption of heat rays, at night there is strong cooling due to radiation. Therefore, the surface layer of air experiences the sharpest daily temperature fluctuations, which are most pronounced over bare soil.
In the ground-air environment, living conditions are complicated by the existence of weather changes. Weather is the continuously changing state of the atmosphere at the earth's surface, up to approximately 20 km altitude. Weather variability is manifested in the constant variation of environmental factors: temperature, air humidity, cloudiness, precipitation, wind strength, direction. The long-term weather regime characterizes the climate of the area. The climate is determined by the geographical conditions of the area. Each habitat is characterized by a certain ecological climate, that is, the climate of the ground layer of air, or ecoclimate.
Geographical zonality and zonality. The distribution of living organisms on Earth is closely related to geographic zones and zones. On the surface of the globe there are 13 geographical zones, which change from the equator to the poles and from the oceans deep into the continents. Within the belts there are latitudinal and meridial, or longitudinal natural areas. The former stretch from west to east, the latter from north to south. Each climate zone is characterized by its own unique vegetation and animal population. Richest in life and productive rainforests, floodplains, prairies and forests of the subtropics and transition zone. Deserts, meadows and steppes are less productive. One of important conditions the variability of organisms and their zonal distribution on earth is variability chemical composition environment. Along with horizontal zonality, altitudinal or vertical zonality is clearly evident in the terrestrial environment. The vegetation of mountainous countries is richer than on the adjacent plains. Adaptations to life in the mountains: plants are dominated by a cushion-shaped life form, perennials, which have developed adaptation to strong ultraviolet radiation and reduced transpiration. In animals, the relative volume of the heart increases and the hemoglobin content in the blood increases. Animals: mountain turkeys, mountain finches, larks, vultures, rams, goats, chamois, yaks, bears, lynxes.
Ground-air environment life is the most difficult due to environmental conditions. In the course of evolution, it was mastered much later than aquatic. Life on land required adaptations that became possible only with a sufficiently high level of organization of organisms. The ground-air environment is characterized by low air density, large fluctuations in temperature and humidity, higher intensity of solar radiation in comparison with other environments, and atmospheric mobility.
Low air density and mobility determine its low lifting force and insignificant support. Organisms of the terrestrial environment must have a support system that supports the body: plants - mechanical tissues, animals - a hard or hydrostatic skeleton.
The low lifting force of the air determines the maximum mass and size of terrestrial organisms. The largest land animals are significantly smaller than the giants of the aquatic environment - whales. Animals the size and mass of a modern whale could not live on land, as they would be crushed by their own weight.
Low air density causes low resistance to movement. Therefore, many animals acquired the ability to fly: birds, insects, some mammals and reptiles.
Thanks to the mobility of air, passive flight of some types of organisms, as well as pollen, spores, fruits and seeds of plants, is possible. Dispersal with the help of air currents is called anemochory. Organisms passively transported by air currents are called aeroplankton. They are characterized by very small body sizes, the presence of outgrowths and strong dismemberment, the use of cobwebs, etc. The seeds and fruits of anemochoric plants also have very small sizes (seeds of orchids, fireweed, etc.) or various wing-shaped (maple, ash) and parachute-shaped (dandelion, coltsfoot) appendages.
In many plants, pollen transfer is carried out using the wind, for example, in gymnosperms, beech, birch, elm, cereals, etc. The method of pollinating plants with the help of wind is called anemophilia. Wind-pollinated plants have many adaptations that ensure efficient pollination.
Winds blowing with great force (storms, hurricanes) break trees, often uprooting them. Winds constantly blowing in one direction cause various deformations in tree growth and cause the formation of flag-shaped crowns.
In areas where strong winds constantly blow, it is usually poor species composition small flying animals, since they are not able to resist powerful air currents. Thus, on oceanic islands with constant strong winds, birds and insects that have lost the ability to fly predominate. Wind increases the loss of moisture and heat from organisms, and under its influence desiccation and cooling of organisms occurs faster.
Low air density causes relatively low pressure on land (760 mm Hg). As altitude increases, pressure decreases, which may limit the distribution of species in mountains. A decrease in pressure entails a decrease in oxygen supply and dehydration of animals due to an increase in respiration rate. Therefore, for most vertebrates and higher plants, the upper limit of life is about 6000 m.
Gas composition of air V ground layer The atmosphere is quite homogeneous. It contains nitrogen - 78.1%, oxygen - 21%, argon - 0.9%, carbon dioxide - 0.03%. In addition to these gases, the atmosphere contains small amounts of neon, krypton, xenon, hydrogen, helium, as well as various aromatic emissions from plants and various impurities: sulfur dioxide, oxides of carbon, nitrogen, and physical impurities. The high oxygen content in the atmosphere contributed to an increase in metabolism in terrestrial organisms and the emergence of warm-blooded (homeothermic) animals. Oxygen deficiency can occur in accumulations of decomposing plant debris, grain reserves, and the root systems of plants on waterlogged or overly compacted soils can experience a lack of oxygen.
The carbon dioxide content can vary in certain areas of the surface layer of air within fairly significant limits. In the absence of wind in large cities, its concentration can increase tens of times. There are regular daily and seasonal changes in the carbon dioxide content in the surface layer of air, caused by changes in the intensity of photosynthesis and respiration of organisms. In high concentrations, carbon dioxide is toxic, and in low concentrations it reduces the rate of photosynthesis.
Air nitrogen is an inert gas for most organisms in the terrestrial environment, but many prokaryotic organisms (nodule bacteria, Azotobacter, clostridia, cyanobacteria, etc.) have the ability to bind it and involve it in the biological cycle.
Many contaminants released into the air, mainly as a result of human activities, can significantly affect organisms. For example, sulfur oxide is toxic to plants even in very low concentrations; it causes the destruction of chlorophyll, damages the structure of chloroplasts, and inhibits the processes of photosynthesis and respiration. The damage to plants by toxic gases varies and depends on their anatomical, morphological, physiological, biological and other characteristics. For example, lichens, spruce, pine, oak, and larch are especially sensitive to industrial gases. The most resistant are Canadian poplar, balsam poplar, ash maple, thuja, red elderberry and some others.
Light mode. Solar radiation reaching the Earth's surface is the main source of energy for maintaining the thermal balance of the planet, the water metabolism of organisms, and the creation of organic matter by plants, which ultimately makes it possible to form an environment capable of satisfying the vital needs of organisms. Solar radiation reaching the Earth's surface includes ultraviolet rays with a wavelength of 290–380 nm, visible rays with a wavelength of 380–750 nm, and infrared rays with a wavelength of 750–4000 nm. Ultraviolet rays are highly chemically active and in large doses are harmful to organisms. In moderate doses in the range of 300–380 nm, they stimulate cell division and growth, promote the synthesis of vitamins, antibiotics, pigments (for example, tan in humans, dark caviar in fish and amphibians), and increase plant resistance to diseases. Infrared rays have a thermal effect. Photosynthetic bacteria (green, purple) are able to absorb infrared rays in the range of 800–1100 nm and exist only at their expense. Approximately 50% of solar radiation comes from visible light, which has different ecological significance in the life of autotrophic and heterotrophic organisms. Green plants need light for the process of photosynthesis, the formation of chlorophyll, and the formation of chloroplast structure. It affects gas exchange and transpiration, the structure of organs and tissues, and the growth and development of plants.
For animals, visible light is necessary for orientation in the environment. In some animals, visual perception extends to the ultraviolet and near-infrared parts of the spectrum.
The light regime of any habitat is determined by the intensity of direct and diffuse light, its quantity, spectral composition, as well as the reflectivity of the surface on which the light falls. These elements of the light regime are very variable and depend on the geographic latitude of the area, the height of the sun above the horizon, the length of the day, the state of the atmosphere, the nature of the earth's surface, relief, time of day and season of the year. In this regard, during the long process of evolution, terrestrial organisms have developed various adaptations to the light regime of their habitats.
Plant adaptations. In relation to lighting conditions, there are three main environmental groups plants: light-loving (heliophytes); shade-loving (sciophytes); shade-tolerant.
Heliophytes– plants of open, well-lit habitats. They do not tolerate shade. Examples of them can be steppe and meadow plants of the upper tier of the community, species of deserts, alpine meadows, etc.
Sciophytes– do not tolerate strong lighting from direct sunlight. These are plants of the lower tiers of shady forests, caves, rock crevices, etc.
Shade-tolerant plants have a wide ecological valency in relation to light. They grow better under high light intensity, but also tolerate shading well, and adapt to changing light conditions more easily than other plants.
Each group of plants considered is characterized by certain anatomical, morphological, physiological and seasonal adaptations to light conditions.
One of the most obvious differences in the appearance of light-loving and shade-loving plants is the unequal size of the leaves. In heliophytes they are usually small or with a dissected leaf blade. This is especially clearly seen when comparing related species growing in different lighting conditions (field violet and forest violets, spreading bell growing in meadows, and forest bell, etc.). The tendency to increase the size of leaves in relation to the entire volume of plants is clearly expressed in herbaceous plants spruce forest: common wood sorrel, bifolia mynika, crow's eye, etc.
In light-loving plants, in order to reduce the amount of solar radiation, the leaves are arranged vertically or at an acute angle to the horizontal plane. In shade-loving plants, the leaves are arranged predominantly horizontally, which allows them to receive the maximum amount of incident light. The leaf surface of many heliophytes is shiny, facilitating the reflection of rays, covered with a waxy coating, thick cuticle or dense pubescence.
The leaves of shade-loving and light-loving plants also differ anatomical structure. Light leaves have more mechanical tissues and the leaf blade is thicker than shadow leaves. The mesophyll cells are small, densely arranged, the chloroplasts in them are small and light-colored, and occupy a wall position. The leaf mesophyll is differentiated into columnar and spongy tissues.
Sciophytes have thinner leaves, the cuticle is absent or poorly developed. Mesophyll is not differentiated into columnar and spongy tissue. There are fewer elements of mechanical tissues and chloroplasts in shade leaves, but they are larger than those of heliophytes. Shoots of light-loving plants often have shortened internodes, are highly branched, and often rosette-shaped.
Physiological adaptations of plants to light are manifested in changes in growth processes, intensity of photosynthesis, respiration, transpiration, composition and quantity of pigments. It is known that in light-loving plants, when there is a lack of light, the stems become elongated. The leaves of shade-loving plants contain more chlorophyll than light-loving ones, so they have a more saturated dark green color. The intensity of photosynthesis in heliophytes is maximum at high illumination (within 500-1000 lux or more), and in sciophytes - at low amounts of light (50-200 lux).
One of the forms of physiological adaptation of plants to a lack of light is the transition of some species to heterotrophic nutrition. An example of such plants are species of shady spruce forests - creeping goodyera, true nesting plant, and common spruce grass. They live off dead organic matter, i.e. are saprophytes.
Seasonal adaptations of plants to lighting conditions are manifested in habitats where the light regime periodically changes. In this case, plants in different seasons can manifest themselves either as light-loving or shade-tolerant. For example, in the spring in deciduous forests, the leaves of the shoots of the common pine tree have a light structure and are characterized by a high intensity of photosynthesis. The leaves of the summer shoots of the tree, which develop after the leafing of trees and shrubs, have a typical shadow structure. The attitude towards the light regime in plants can change during the process of ontogenesis and as a result of the complex influence of environmental factors. Seedlings and young plants of many meadow and forest species are more shade-tolerant than adult plants. Requirements for the light regime sometimes change in plants when they find themselves in different climatic and edaphic conditions. For example, forest taiga species - blueberry, bileaf - in the forest-tundra and tundra grow well in open habitats.
One of the factors regulating the seasonal development of organisms is the length of the day. The ability of plants and animals to respond to day length is called photoperiodic reaction(FPR), and the range of phenomena regulated by the length of the day is called photoperiodism. Based on the type of photoperiodic reaction, the following main groups of plants are distinguished:
1. Short day plants, which require less than 12 hours of light per day to begin flowering. These, as a rule, come from the southern regions (chrysanthemums, dahlias, asters, tobacco, etc.).
2. Plants have a long day – for flowering they need a day length of 12 hours or more (flax, oats, potatoes, radishes).
3. Neutral to day length plants. For them, the length of the day is indifferent; flowering occurs at any length (dandelion, tomatoes, mustard, etc.).
The length of the day affects not only the passage of the plant’s generative phases, but also its productivity and resistance to infectious diseases. It also plays an important role in the geographical distribution of plants and regulation of their seasonal development. Species common in northern latitudes are predominantly long-day, while in the tropics and subtropics they are mainly short-day or neutral. However, this pattern is not absolute. Thus, long-day species are found in the mountains of the tropical and subtropical zones. Many varieties of wheat, flax, barley and others cultivated plants, originating from the southern regions, have a long-day FPR. Research has shown that when temperatures drop, long-day plants can develop normally under short-day conditions.
Light in the life of animals. Animals need light for orientation in space; it also affects metabolic processes, behavior, life cycle. Completeness visual perception environment depends on the level of evolutionary development. Many invertebrates have only light-sensitive cells surrounded by pigment, while unicellular organisms have a light-sensitive portion of the cytoplasm. The most perfect are the eyes of vertebrates, cephalopods and insects. They allow you to perceive the shape and size of objects, color, and determine distance. Three-dimensional vision is typical for humans, primates, and some birds (eagles, falcons, owls). The development of vision and its features also depend on the environmental conditions and lifestyle of specific species. In cave dwellers, the eyes can be completely or partially reduced, as, for example, in the blind beetles, ground beetles, proteas, etc.
Different species of animals are able to withstand lighting of a certain spectral composition, duration and intensity. There are light-loving and shade-loving, euryphotic And stenophotic kinds. Nocturnal and crepuscular mammals (voles, mice, etc.) tolerate direct sunlight for only 5–30 minutes, and daytime mammals – for several hours. However, in bright sunlight, even desert species of lizards cannot withstand irradiation for long, since within 5–10 minutes their body temperature rises to +50–56ºС and the animals die. Illumination of the eggs of many insects accelerates their development, but up to certain limits (not the same for various types), after which development stops. An adaptation to protection from excessive solar radiation is the pigmented integument of some organs: in reptiles - the abdominal cavity, reproductive organs, etc. Animals avoid excessive radiation by going into shelters, hiding in the shadows, etc.
Daily and seasonal changes in light conditions determine not only changes in activity, but also periods of reproduction, migration, and molting. The appearance of nocturnal insects and the disappearance of daytime insects in the morning or evening occur at a specific lighting brightness for each species. For example, the marbled beetle appears 5–6 minutes after sunset. When songbirds wake up varies from season to season. Depending on the illumination, the hunting areas of birds change. Thus, woodpeckers, tits, and flycatchers hunt in the depths of the forest during the day, and in open places in the morning and evening. Animals navigate using vision during flights and migrations. Birds choose their flight direction with amazing accuracy, guided by the sun and stars. This innate ability is created by natural selection as a system of instincts. The ability for such orientation is also characteristic of other animals, for example, bees. Bees that have found nectar transmit information to others about where to fly for a bribe, using the sun as a guide.
Light conditions limit the geographic distribution of some animals. Thus, a long day during the summer months in the Arctic and temperate zone attracts birds and some mammals there, as it allows them to get the right amount of food (tits, nuthatches, waxwings, etc.), and in the fall they migrate south. The light regime has the opposite effect on the distribution of nocturnal animals. In the north they are rare, and in the south they even predominate over daytime species.
Temperature conditions. The intensity of all chemical reactions that make up metabolism depends on temperature conditions. Therefore, the boundaries of the existence of life are the temperatures at which normal functioning of proteins is possible, on average from 0 to +50ºС. However, these thresholds are not the same for different species of organisms. Thanks to the presence of specialized enzyme systems, some organisms have adapted to live at temperatures beyond specified limits. Species adapted to life in cold conditions belong to the ecological group cryophiles. In the process of evolution, they have developed biochemical adaptations that allow them to maintain cellular metabolism at low temperatures, as well as resist freezing or increase resistance to it. The accumulation of special substances in the cells - antifreeze, which prevent the formation of ice crystals in the body, helps to resist freezing. Such adaptations have been identified in some Arctic fish of the nototheniaceae and cod family, which swim in the waters of the Arctic Ocean, with a body temperature of –1.86ºС.
The extremely low temperature at which cell activity is still possible has been recorded for microorganisms – down to –10–12ºС. Resistance to freezing in some species is associated with the accumulation in their body of organic substances, such as glycerin, mannitol, and sorbitol, which prevent the crystallization of intracellular solutions, which allows them to survive critical frosty periods in an inactive state (torpor, cryptobiosis). Thus, some insects can withstand temperatures down to –47–50ºС in winter in this state. Cryophiles include many bacteria, lichens, fungi, mosses, arthropods, etc.
Species whose optimum life activity is confined to the area of high temperatures are classified as an ecological group thermophiles.
Most resistant to high temperatures bacteria, many of which can grow and multiply at +60–75ºС. Some bacteria living in hot springs grow at temperatures of +85–90ºС, and one species of archaebacteria has been found to grow and divide at temperatures exceeding +110ºС. Spore-forming bacteria can withstand +200ºС in an inactive state for tens of minutes. Thermophilic species are also found among fungi, protozoa, plants and animals, but their level of resistance to high temperatures is lower than that of bacteria. Higher plants of steppes and deserts can tolerate short-term heating up to +50–60ºС, but their photosynthesis is already inhibited by temperatures exceeding +40ºС. At a body temperature of +42–43ºС, heat death occurs in most animals.
The temperature regime in the terrestrial environment varies widely and depends on many factors: latitude, altitude, proximity of water bodies, time of year and day, state of the atmosphere, vegetation cover, etc. During the evolution of organisms, various adaptations have been developed that make it possible to regulate metabolism when the ambient temperature changes. This is achieved in two ways: 1) biochemical and physiological changes; 2) maintaining body temperature at a more stable level than the ambient temperature. The life activity of most species depends on heat coming from outside, and body temperature depends on the course of external temperatures. Such organisms are called poikilothermic. These include all microorganisms, plants, fungi, invertebrate animals and most chordates. Only birds and mammals are able to maintain a constant body temperature regardless of the ambient temperature. They are called homeothermic.
Adaptation of plants to temperature conditions. The resistance of plants to changes in environmental temperature is different and depends on the specific habitat where their life takes place. Higher plants of moderately warm and moderately cold zones eurytherms. In the active state, they tolerate temperature fluctuations from – 5 to +55ºС. At the same time, there are species that have a very narrow ecological valency in relation to temperature, i.e. are stenothermic. For example, plants tropical forests They cannot even tolerate temperatures of +5–+8ºС. Some algae on snow and ice live only at 0ºC. That is, the heat needs of different plant species are not the same and vary over a fairly wide range.
Species living in places with constantly high temperatures, in the process of evolution, acquired anatomical, morphological and physiological adaptations aimed at preventing overheating.
The main anatomical and morphological adaptations include: dense leaf pubescence, shiny leaf surface, which helps reflect sunlight; reduction in leaf area, their vertical position, curling into a tube, etc. Some species are capable of secreting salts, from which crystals are formed on the surface of plants, reflecting the rays of the sun falling on them. In conditions of sufficient moisture, stomatal transpiration is an effective remedy for overheating. Among thermophilic species, depending on the degree of their resistance to high temperatures, we can distinguish
1) non-heat resistant plants are damaged already at +30–40ºС;
2) heat-tolerant– tolerate half-hour heating up to +50–60ºС (plants of deserts, steppes, dry subtropics, etc.).
Plants in savannas and dry hardwood forests are regularly affected by fires, where temperatures can rise to hundreds of degrees. Plants that are resistant to fire are called pyrophytes. They have a thick crust on their trunks, impregnated with fire-resistant substances. Their fruits and seeds have thick, often lignified integuments.
The life of many plants passes in conditions of low temperatures. According to the degree of adaptation of plants to conditions of extreme heat deficiency, the following groups can be distinguished:
1) non-cold-resistant plants are severely damaged or killed at temperatures below the freezing point of water. These include plants from tropical areas;
2) non-frost-resistant plants - tolerate low temperatures, but die as soon as ice begins to form in the tissues (some evergreen subtropical plants).
3) frost-resistant plants grow in areas with cold winters.
Resistance to low temperatures is increased by such morphological adaptations of plants as short stature and special forms of growth - creeping, cushion-shaped, which allow them to use the microclimate of the ground layer of air in summer and be protected by snow cover in winter.
More significant for plants are physiological adaptation mechanisms that increase their resistance to cold: leaf fall, death of above-ground shoots, accumulation of antifreeze in cells, decrease in water content in cells, etc. In frost-resistant plants, in the process of preparing for winter, sugars, proteins, etc. accumulate in the organs. oil, the water content in the cytoplasm decreases and its viscosity increases. All these changes reduce the freezing point of tissues.
Many plants are able to remain viable in a frozen state, for example, alpine violet, arctic horseradish, woodlice, daisy, early spring ephemeroids in the forest zone, etc.
Mosses and lichens are able to withstand prolonged freezing in a state of suspended animation. Of great importance in the adaptation of plants to low temperatures is the possibility of maintaining normal life activity by reducing the temperature optimum of physiological processes and the lower temperature limits at which these processes are possible.
In temperate and high latitudes due to seasonal change climatic conditions In plants, active and dormant phases alternate in the annual development cycle. Annual plants, after the completion of the growing season, survive the winter in the form of seeds, and perennial plants go into a dormant state. Distinguish deep And compelled peace. Plants in a state of deep dormancy do not respond to favorable thermal conditions. After deep dormancy ends, plants are ready to resume development, but in nature in winter this is impossible due to low temperatures. Therefore, this phase is called forced rest.
Adaptation of animals to temperature conditions. Compared to plants, animals have a greater ability to regulate their body temperature due to their ability to move through space and produce much more of their own internal heat.
The main ways of animal adaptation:
1) chemical thermoregulation– this is a reflex increase in heat production in response to a decrease in environmental temperature, based on a high level of metabolism;
2) physical thermoregulation– is carried out due to the ability to retain heat due to special structural features (presence of hair and feathers, distribution of fat reserves, etc.) and changes in the level of heat transfer;
3) behavioral thermoregulation- this is a search for favorable habitats, a change in posture, the construction of shelters, nests, etc.
For poikilothermic animals, the main way to regulate body temperature is behavioral. In extreme heat, animals hide in the shade and holes. As winter approaches, they seek shelter, build nests, and reduce their activity. Some species are able to maintain optimal body temperature through muscle function. For example, bumblebees warm up their bodies with special muscle contractions, which allows them to feed in cool weather. Some poikilothermic animals avoid overheating by increasing heat loss through evaporation. For example, frogs and lizards in hot weather begin to breathe heavily or keep their mouths open, increasing the evaporation of water through the mucous membranes.
Homeothermic animals are distinguished by very efficient regulation of heat input and output, which allows them to maintain a constant optimal body temperature. Their thermoregulation mechanisms are very diverse. They are characterized chemical thermoregulation, characterized by a high metabolic rate and the production of large amounts of heat. Unlike poikilothermic animals, in warm-blooded animals, when exposed to cold, oxidative processes do not weaken, but intensify. Many animals generate additional heat from muscle and fat tissue. Mammals have specialized brown adipose tissue, in which all the released energy is used to warm the body. It is most developed in animals of cold climates. Maintaining body temperature by increasing heat production requires a large expenditure of energy, so animals, with increased chemical regulation, need a large amount of food or spend a lot of fat reserves. Therefore, the strengthening of chemical regulation has limits determined by the possibility of obtaining food. If there is a lack of food in winter, this method of thermoregulation is environmentally unprofitable.
Physical thermoregulation It is environmentally more beneficial, since adaptation to cold is carried out by retaining heat in the animal’s body. Its factors are the skin, thick fur of mammals, feather and down cover of birds, fat deposits, evaporation of water through sweating or through the mucous membranes of the oral cavity and upper respiratory tract, the size and shape of the animal’s body. To reduce heat transfer, large body sizes are more advantageous (the larger the body, the smaller its surface per unit mass, and, consequently, heat transfer, and vice versa). For this reason, individuals of closely related species of warm-blooded animals that live in cold conditions are larger in size than those that are common in warm climates. This pattern is called Bergman's rules. Temperature regulation is also carried out through protruding parts of the body - ears, limbs, tails, olfactory organs. In cold areas, they tend to be smaller in size than in warmer areas ( Allen's rule). For homeothermic organisms, they are also important behavioral methods of thermoregulation, which are very diverse - from changing posture and searching for shelter to constructing complex shelters, nests, and carrying out short and long-distance migrations. Some warm-blooded animals use group behavior. For example, penguins huddle together in a dense heap in severe frost. Inside such a cluster, the temperature is maintained around +37ºС even in the most severe frosts. Camels in the desert also huddle together in extreme heat, but this prevents the surface of the body from becoming too hot.
The combination of various methods of chemical, physical and behavioral thermoregulation allows warm-blooded animals to maintain a constant body temperature in a wide range of fluctuations in environmental temperature conditions.
Water mode. Normal functioning of the body is possible only with sufficient supply of water. Humidity regimes in the ground-air environment are very diverse - from complete saturation of the air with water vapor in the humid tropics to almost complete absence moisture in the air and soil of deserts. For example, in the Sinai Desert the annual rainfall is 10–15 mm, while in the Libyan Desert (in Aswan) there is none at all. The water supply of terrestrial organisms depends on the precipitation regime, the presence of soil moisture reserves, reservoirs, groundwater levels, terrain, atmospheric circulation characteristics, etc. This has led to the development of many adaptations in terrestrial organisms to various moisture regimes of habitats.
Plant adaptations to water regime. Lower terrestrial plants absorb water from the substrate by parts of the thallus or rhizoids immersed in it, and moisture from the atmosphere by the entire surface of the body.
Among higher plants, mosses absorb water from the soil through rhizoids or the lower part of the stem (sphagnum mosses), while most others absorb water through their roots. The flow of water into the plant depends on the magnitude of the suction force of the root cells, the degree of branching of the root system and the depth of penetration of the roots into the soil. Root systems are very plastic and respond to changing conditions, primarily moisture.
When there is a lack of moisture in the surface horizons of the soil, many plants have root systems that penetrate deep into the soil, but are weakly branched, as, for example, in saxaul, camel thorn, Scots pine, rough cornflower, etc. In many cereals, on the contrary, the root systems are strongly branched and grow in the surface layers of the soil (in rye, wheat, feather grass, etc.). The water entering the plant is carried through the xylem to all organs, where it is spent on life processes. On average, 0.5% goes to photosynthesis, and the rest to replenish losses from evaporation and maintain turgor. The water balance of a plant remains balanced if the absorption of water, its conduction and expenditure are harmoniously coordinated with each other. Depending on their ability to regulate the water balance of their body, land plants are divided into poikihydride and homoyohydride.
Poikihydrid plants are unable to actively regulate their water balance. They do not have devices that help retain water in their tissues. The water content in cells is determined by air humidity and depends on its fluctuations. Poikilohydride plants include terrestrial algae, lichens, some mosses and tropical forest ferns. During the dry period, these plants dry out almost to an air-dry state, but after rain they “come to life” again and turn green.
Homoyohydride plants capable of maintaining the water content in cells at a relatively constant level. These include most higher land plants. Their cells have a large central vacuole, due to which there is always a supply of water. In addition, transpiration is regulated by the stomatal apparatus, and the shoots are covered with an epidermis with a cuticle that is poorly permeable to water.
However, the ability of plants to regulate their water metabolism is not the same. Depending on their adaptability to the moisture conditions of habitats, three main ecological groups are distinguished: hygrophytes, xerophytes and mesophytes.
Hygrophytes- These are plants of wet habitats: swamps, damp meadows and forests, and the banks of reservoirs. They cannot tolerate water deficiency and react to decreased soil and air humidity by rapid wilting or inhibition of growth. Their leaf blades are wide and do not have a thick cuticle. Mesophyll cells are loosely arranged, with large intercellular spaces between them. The stomata of hygrophytes are usually wide open and are often located on both sides of the leaf blade. In this regard, their transpiration rate is very high. In some plants in highly humid habitats, excess water is removed through hydathodes (water stomata) located along the edge of the leaf. Excessive soil moisture leads to a decrease in the oxygen content in it, which complicates the breathing and suction function of the roots. Therefore, the roots of hygrophytes are located in the surface horizons of the soil, they are weakly branched, and there are few root hairs on them. The organs of many herbaceous hygrophytes have a well-developed system of intercellular spaces through which atmospheric air enters. Plants that live on heavily waterlogged soils, periodically flooded with water, form special respiratory roots, such as swamp cypress, or support roots, such as mangrove woody plants.
Xerophytes In an active state, they are able to tolerate significant prolonged dryness of air and soil. They are widespread in steppes, deserts, dry subtropics, etc. In the zone temperate climate settle on dry sandy and sandy loam soils, in elevated areas of the relief. The ability of xerophytes to tolerate a lack of moisture is due to their anatomical, morphological and physiological characteristics. Based on these characteristics, they are divided into two groups: succulents And sclerophytes.
Succulents- perennial plants with succulent, fleshy leaves or stems, in which water-storing tissue is highly developed. There are leaf succulents - aloe, agaves, sedums, young and stem ones, in which the leaves are reduced, and the ground parts are represented by fleshy stems (cacti, some milkweeds). A distinctive feature of succulents is their ability to store large amounts of water and use it extremely economically. Their transpiration rate is very low, since there are very few stomata, they are often immersed in the tissue of the leaf or stem and are usually closed during the day, which helps them limit water consumption. Closing the stomata during the day impedes the processes of photosynthesis and gas exchange, so succulents have developed a special route of photosynthesis, which partially uses carbon dioxide released during respiration. In this regard, their photosynthesis rate is low, which is associated with slow growth and rather low competitiveness. Succulents are characterized by low osmotic pressure of cell sap, with the exception of those that grow in saline soils. Their root systems are superficial, highly branched and fast growing.
Sclerophytes are hard, dry-looking plants due to the large amount of mechanical tissue and low water content of the leaves and stems. The leaves of many species are small, narrow or reduced to scales and spines; often have dense pubescence (cat's paw, silver cinquefoil, many wormwoods, etc.) or a waxy coating (Russian cornflower, etc.). Their root systems are well developed and often have a total mass many times greater than the above-ground parts of plants. Various physiological adaptations also help sclerophytes successfully withstand the lack of moisture: high osmotic pressure of cell sap, resistance to tissue dehydration, high water-holding capacity of tissues and cells due to the high viscosity of the cytoplasm. Many sclerophytes use the most favorable periods of the year for vegetation, and when drought occurs, they sharply reduce vital processes. All of the listed properties of xerophytes contribute to increasing their drought resistance.
Mesophytes grow in average moisture conditions. They are more demanding of moisture than xerophytes, and less demanding than hygrophytes. Leaf tissues of mesophytes are differentiated into columnar and spongy parenchyma. The integumentary tissues may have some xeromorphic features (sparse pubescence, thickened cuticle layer). But they are less pronounced than in xerophytes. Root systems can penetrate deep into the soil or be located in surface horizons. In terms of their ecological needs, mesophytes are a very diverse group. Thus, among meadow and forest mesophytes there are species with increased love for moisture, which are characterized by a high water content in tissues and a rather weak water-holding capacity. These are meadow foxtail, swamp bluegrass, soddy meadow grass, Linnaeus holocum and many others.
In habitats with periodic or constant (small) lack of moisture, mesophytes have signs of xeromorphic organization and increased physiological resistance to drought. Examples of such plants are pedunculate oak, mountain clover, middle plantain, crescent alfalfa, etc.
Animal adaptations. In relation to the water regime, animals can be divided into hygrophiles (moisture-loving), xerophiles (dry-loving) and mesophiles (preferring average moisture conditions). Examples of hygrophiles are wood lice, mosquitoes, springtails, dragonflies, etc. All of them cannot tolerate significant water deficits and do not tolerate even short-term drought. Monitor lizards, camels, desert locusts, darkling beetles, etc. are xerophilous. They inhabit the most arid habitats.
Animals obtain water through drinking, food and through the oxidation of organic substances. Many mammals and birds (elephants, lions, hyenas, swallows, swifts, etc.) need drinking water. Desert species such as jerboas, African gerbils, and the American kangaroo rat can survive without drinking water. Clothes moth caterpillars, granary and rice weevils, and many others live exclusively on metabolic water.
Animals have typical ways to regulate water balance: morphological, physiological, behavioral.
TO morphological methods of maintaining water balance include formations that help retain water in the body: shells of land snails, keratinized integuments of reptiles, weak water permeability of insect integuments, etc. It has been shown that the permeability of insect integuments does not depend on the structure of chitin, but is determined by the thinnest waxy layer covering its surface . The destruction of this layer sharply increases evaporation through the covers.
TO physiological adaptations for regulating water metabolism include the ability to form metabolic moisture, saving water during the excretion of urine and feces, tolerance to dehydration, changes in sweating and water release through the mucous membranes. Saving water in the digestive tract is achieved by the absorption of water by the intestines and the formation of practically dehydrated feces. In birds and reptiles, the end product of nitrogen metabolism is uric acid, for the removal of which practically no water is consumed. Active regulation of sweating and evaporation of moisture from the surface of the respiratory tract is widely used by homeothermic animals. For example, in the most extreme cases of moisture deficiency in a camel, sweating stops and evaporation from the respiratory tract is sharply reduced, which leads to water retention in the body. Evaporation, associated with the need for thermoregulation, can cause dehydration of the body, so many small warm-blooded animals in dry and hot climates avoid exposure to heat and save moisture by hiding underground.
In poikilothermic animals, an increase in body temperature following warming of the air allows them to avoid unnecessary water loss, but they cannot completely avoid evaporative losses. Therefore, for cold-blooded animals, the main way to maintain water balance when living in arid conditions is to avoid excessive heat loads. Therefore, in the complex of adaptations to the water regime of the terrestrial environment great importance have behavioral ways regulation of water balance. These include special forms of behavior: digging holes, searching for reservoirs, choosing habitats, etc. This is especially important for herbivores and granivores. For many of them, the presence of bodies of water is a prerequisite for settling in arid areas. For example, the distribution in the desert of such species as the Cape buffalo, waterbuck, and some antelopes completely depends on the availability of watering places. Many reptiles and small mammals live in burrows where relatively low temperatures and high humidity promote water exchange. Birds often use hollows, shady tree crowns, etc.
Ground-air environment - a medium consisting of air, which explains its name. It is usually characterized by the following:
- The air provides almost no resistance, so the shell of organisms usually does not flow around.
- High oxygen content in the air.
- There are climates and seasons.
- Closer to the ground, the air temperature is higher, so most species live on the plains.
- There is no water in the atmosphere necessary for life, so organisms settle closer to rivers and other bodies of water.
- Plants that have roots take advantage of the minerals found in the soil and, partly, are found in the soil environment.
- The minimum temperature was recorded in Antarctica, which was - 89 ° C, and the maximum was + 59 ° C.
- The biological environment extends from 2 km below sea level to 10 km above sea level.
In the course of evolution, this environment was developed later than the aquatic one. Its peculiarity is that it gaseous, therefore characterized by low:
- humidity,
- density and pressure,
- high oxygen content.
In the course of evolution, living organisms have developed the necessary anatomical, morphological, physiological, behavioral and other adaptations. Animals in the ground-air environment move on the soil or through the air (birds, insects). In this regard, animals developed lungs and trachea, i.e., the organs with which the land inhabitants of the planet absorb oxygen directly from the air. Received strong development skeletal organs, providing autonomy for movement on land and supporting the body with all its organs in conditions of low density of the environment, thousands of times less than water.
Environmental factors in the ground-air environment differ from other habitats:
- high light intensity,
- significant fluctuations in air temperature and humidity,
- correlation of all factors with geographical location,
- changing seasons of the year and time of day.
Their effects on organisms are inextricably linked with the movement of air and position relative to the seas and oceans and are very different from the effects in the aquatic environment. In the ground-air environment there is enough light and air. However, humidity and temperature are very variable. Swampy areas have an excess amount of moisture, while in the steppes it is much less. Daily and seasonal temperature fluctuations are noticeable.
Adaptations of organisms to life in conditions of different temperatures and humidity. More adaptations of organisms in the land-air environment are associated with air temperature and humidity. Animals of the steppe (scorpion, tarantula and karakurt spiders, gophers, vole mice) hide from the heat in minks. Animals cope with heat by secreting sweat.
With the onset of cold weather, birds fly away to warmer regions so that in the spring they return again to the place where they were born and where they will give birth.
Features of the ground-air environment in southern regions is insufficient moisture. Desert animals must have the ability to conserve their water in order to survive long periods when food is scarce. Herbivores usually manage to do this by storing all the available moisture in the stems and seeds they eat. Carnivores obtain water from the wet flesh of their prey. Both types of animals have very efficient kidneys that conserve every drop of moisture and they rarely need to drink. Also, desert animals must be able to protect themselves from the brutal heat during the day and the piercing cold at night. Small animals can do this by hiding in rock cracks or burrowing in the sand. Many animals have developed an impenetrable outer shell in the process of evolution, not for protection, but to reduce the loss of moisture from their body.
Adaptation of organisms to movement in the land-air environment. For many animals in the land-air environment, movement on the earth's surface or in the air is important. To do this, they have developed certain adaptations, and their limbs have different structures. Some have adapted to running (wolf, horse), others to jumping (kangaroo, jerboa, horse), and others to flying (birds, bats, insects). Snakes and vipers have no limbs at all, so they move by arching their body.
Significantly fewer organisms have adapted to life high in the mountains, since there is little soil, moisture and air, and difficulties arise with movement. However, some animals, such as mouflon mountain goats, are able to move almost vertically up and down if there are even slight irregularities. Therefore, they can live high in the mountains.
Adaptation of animals to the illumination factor of the ground-air environment of life structure and size of the eyes. Most animals in this environment have well-developed visual organs. So, from the height of its flight, a hawk sees a mouse running across the field.