Study of autumn phenomena in the life of animals. Seasonal changes in nature in summer, autumn, winter and spring. Seasonal changes in birch

Main article: Fitness of organisms

One of the great properties nature are her seasonal changes. Temperature, humidity, light and others environmental factors undergo periodic changes throughout the year. Seasonal changes in abiotic environmental factors, in turn, have a great impact on the vital activity of living organisms. IN different regions the period favorable for life has a different duration. For example, in middle lane the globe this period lasts about 6-7 months. Here, the period of winter dormancy is clearly manifested.

As a result of a decrease in temperature and the end of the growing season, many plants slow down their metabolism, and leaf fall begins. The period of winter dormancy is observed in insects, amphibians, reptiles and other animals. Many birds migrate to warmer climes.

photoperiodism

The growth and development of plants and animals depend on the duration of daylight hours. This phenomenon is called photoperiodism.

Photoperiodism is the dependence of the activity of physiological processes of living organisms on the duration of daylight hours. This phenomenon can be observed in experiments on plants and animals with artificial changes in lighting during the day. The processes of plant photosynthesis are also associated with photoperiodism.

Photoperiodism in plant life

The change in day length is accompanied by annual temperature fluctuations. Therefore, the length of the day serves as a signal for seasonal changes. Depending on the response of plants to the length of the day, they are divided into long-day, short-day and neutral plants. The flowering of neutral plants does not depend on the length of the day.

Photoperiodism in animals

The length of the day also has a great influence on the growth and development of animals. So, silkworm caterpillars develop well in conditions of a short day. Photoperiodism also has a strong influence on the timing of the onset of the breeding season, on embryonic development, molting, bird migration and hibernation of mammals and other animals.

Human use

Man, studying the laws of photoperiodism in plants and animals, widely uses them for his practical purposes. An example of this is the year-round cultivation of vegetables and flowers in greenhouses, increasing the egg production of chickens in poultry farms.

Biorhythms

On the basis of photoperiodism in plants and animals, biological rhythms have arisen over the course of evolution that occur with a certain periodicity. Material from the site http://wikiwhat.ru

Biological rhythms are periodically repeated changes in the intensity of biological processes. They can be daily, seasonal and annual. As an example of daily biorhythms, one can point to a change in the intensity of photosynthesis in plants, a change in the speed of movement, hormone production and cell division in animals. A person also observes rhythmic changes during the day in the frequency of breathing, blood pressure and other processes. Since biorhythms are hereditary reactions, for the correct organization of the work and rest regime of a person, one must know their mechanisms well.

Thus, the reactions of organisms to daily and seasonal changes determine their ability to measure time, make them the owners of the "biological clock".

Man in his practical activities widely uses the phenomena of biorhythm.

On this page, material on the topics:

• What changes occur in summer in wildlife

• Seasonal changes in nature abstract grade 10

• Seasonal temperature change report

• What is change in nature

• Seasonal changes in birch

Questions for this article:

• What is photoperiodism?

• What are biological rhythms?

• What is a biological clock?

• What changes are taking place in nature?

• What is the main factor for seasonal changes in plants and animals?

Material from the site http://WikiWhat.ru

Factors affecting the change in air temperature. The annual course of precipitation. The phenomenon of fog, nebula, hoarfrost. Daylight length. Seasonal changes in plant life. Change in leaf color. Adaptations of cold-blooded and warm-blooded animals for wintering.

Seasonal changes in wildlife

Prepared by Nilova Anastasia, a student of grade 10A

Scientific adviser: Soboleva Tatyana Gennadievna

Introduction

“Autumn time, the charm of the eyes ...” this is how A.S. Pushkin spoke about autumn. There are also many folk proverbs and sayings about autumn, for example: “Autumn is eight changes; sows, blows, twists, stirs, tears, sapit, pours from above, sweeps from below.

September reluctantly closes the summer. Signs of autumn are visible everywhere: the grass withers, the air cools down, the first yellow leaf breaks from the trees. This month was called "leaf fall", "summer seller", "spring" - another name for September. This is the time of flowering heather - an evergreen low shrub, often found in Polissya, in forests and sometimes in the forest-steppe. Indeed, with the onset of autumn, the leaves on the trees are painted in golden tones, it becomes colder, the length of the day changes. The sun is getting less and less and it is raining more and more. But why is this happening? Why do such changes occur in nature, the life of plants and animals?

1. Changing weather conditions

Annual temperature variation. The air temperature is constantly changing throughout the year. During the transition from summer to autumn, the temperature drops. First of all, the temperature changes due to a change in the angle of incidence. sun rays.

The greater the angle of incidence of the sun's rays, the more solar energy per unit area earth's surface, which means that the more it heats up, and the more the air from it heats up.

In autumn, the angle of incidence of sunlight is less than in summer, so there is a noticeable decrease in air temperature.

However, the change in air temperature can also be affected by the movement of air masses: the arrival of warm or cold air masses can significantly change the typical daily course of air temperature.

Also, the change in air temperature during its descending and ascending movements largely depends on how much water vapor it contains.

Precipitation. Atmospheric precipitation is the moisture contained in clouds, which falls on the Earth in various forms: snow, rain, hail, etc. The annual course of precipitation is different at different latitudes and even within the same zone. It depends on the amount of heat, thermal regime, air circulation, distance from the coast, the nature of the relief. Precipitation is formed during the water cycle in nature. Water evaporates from the surface of bodies of water, rises and condenses at high altitude, and then falls to the ground as precipitation. In autumn, this process is more intense due to the frequent change of warm and cold fronts.

The phenomenon of fog, nebula, hoarfrost. Fog is a thick cloud that forms near the surface of the earth. A sharp temperature drop in the early morning hours raises moisture into the air, concentrating it in it. As soon as the temperature rises, the fog will dissipate, and the moisture will again fall to the ground. Fog is formed when cold air meets warm air.

Hoarfrost is particles of frozen dew. They look like prickly snowflakes, covering all surfaces with an uneven, prickly layer. As a rule, the appearance of a light ice cover indicates that negative temperatures and the first frosts have appeared.

Daylight length. In autumn, daylight hours become shorter and nights longer. This is due to the speed of the Earth's orbit. The Earth's axis of rotation is tilted, so the length of daylight changes throughout the year. Its duration also varies with geographic latitude.

Conclusion: Autumn is the time of the change of southern warm and northern cold air currents, which makes the weather sometimes rainy and rainy, sometimes warm and dry. The influx of solar heat is reduced. The weather in autumn is unstable, it often rains, but in the first half of September, good clear sunny days are not uncommon.

2. Seasonal changes in plant life

Herbaceous plants: most herbaceous plants, namely, the stems and leaves die off for the winter, less often remain in the form of underground modified roots, tubers, rhizomes, bulbs in which there is a supply of nutrients, and can be used by the plant next year for a new vegetative period.

Flowers: the withering of a flower means only the transition to a new stage in the life of the plant. In most cases it depends on temperature regime autumn, as well as from excessive humidity, lack of light.

Change in color and fall of leaves: in summer the leaves have green color due to the large amount of chlorophyll pigment contained in them. However, along with chlorophyll, green leaves contain other pigments - yellow xanthophyll and orange carotene. In summer, these pigments are invisible, as they are disguised big amount chlorophyll. In autumn, as the vital activity in the leaf dies out, chlorophyll is gradually destroyed. This is where the yellow and red shades of xanthophyll and carotene appear in the leaf. The destruction of chlorophyll is more intense in the light, that is, in sunny weather. That is why in cloudy rainy autumn the leaves retain their green color longer. But if the "Indian summer" comes to replace the long rains, then the crowns of the trees turn into golden colors of autumn in 1-2 days. In addition to gold, the autumn dresses of trees contain crimson hues. This color is due to a pigment called anthocyanin. With a decrease in temperature, as well as in bright light, the amount of anthocyanin in the cell sap increases.

Conclusions: Autumn is a turning point of the year: for short term From September to November, nature undergoes a transition from heat to frost, from greenery to snow, from summer to winter. It takes only 3 months for the green-leaved forest with lush grass cover to take on a completely winter look - leafless, bare trees against a white background of snow.

3. Seasonal changes in animal life

Adaptations of cold-blooded animals for wintering. Cold-blooded animals endure the winter in an inactive state. In their body, changes occur that begin well in advance in the summer. By autumn, their nutrient reserves increase, due to which metabolism is maintained at a slow pace. The amount of water in their cells decreases. Despite this preparedness, many cold-blooded animals hibernate in shelters where the harsh conditions of winter are less pronounced.

Adaptations of warm-blooded animals for wintering. Warm-blooded animals have less ability to hypothermia than cold-blooded ones. A constant body temperature is ensured by their high metabolic rate. To maintain the temperature at the same level, they develop such features as heat-insulating covers, fat deposits, etc. To reduce heat transfer in winter conditions, they have an autumn molt - a change in summer fur in mammals and plumage in birds to thicker, winter. Warm-blooded animals do not go into winter dormancy if they can feed themselves in the winter. Mammals that are unable to forage in winter conditions hibernate. Before hibernation, animals accumulate in the body nutrients, mostly fats up to 40% of body weight, and settle into a shelter.

Birds that are not able to provide themselves with food in winter conditions fly away to warmer climes, where they find abundant food.

Conclusions: In the spring, when it gets warm, migratory birds arrive, mammals wake up from hibernation, cold-blooded animals come out of a state of stupor. In autumn, with the onset of cold weather, they have the opposite. It has been established that the main regulating factor of seasonal changes in the life of animals is not a change in temperature, but changes in the length of the day during the year.

rainfall animal wintering seasonal

Autumn is a magical time of the year. All paths in the park are covered with foliage and needles. Raindrops thump the ground in a muffled rhythm. And with the fall, step by step, we are approaching changes. Autumn is the harbinger of winter, the time of the onset of the first cold weather. Autumn is the time when the sky turns dark and the days short. Autumn is the time of learning. Autumn is the season of rains. Autumn is the time of poets. And autumn is the first snow. And that means winter is coming...

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Section: "Fundamentals of Ecology" (8 hours)

Seasonal periodicity in nature.

1. The subject and basic concepts of ecology.

Ecological factors of the environment.

1. The subject and tasks of ecology. Place of ecology among biological sciences.
2. The effect of environmental factors on living organisms.
3. Forecasting and modeling.
4. Seasonal phenomena in nature.

1. The subject and tasks of ecology.

Place of ecology among biological sciences.

Ecology is the science of the patterns of relationships between organisms and the organic nature surrounding them. This term was introduced in 1866. E. Haeckel.

Tasks of ecology: the study of the relationship of organisms and their populations with the environment, the study of the effect of the environment on the structure, vital activity and behavior of the organism, the establishment of a relationship between the environment and the number of populations, the study of the struggle for existence in populations and the direction of natural selection. Ecology studies the relationship between populations of different species in a community, between populations and environmental factors, their influence on the distribution of species, on the development and change of communities. Ecology is inextricably linked with evolutionary doctrine, especially with the problems of microevolution, as it studies the processes occurring in populations.

The object of study is ecosystems. Ecology is classified according to specific objects of study: the ecology of microorganisms, the ecology of plants, the ecology of animals, the ecology of man. Particular attention is paid to the interaction of man with the environment.
Ecology is of great importance for the development of various sectors of the national economy. Most important areas application of environmental knowledge is the protection of nature, Agriculture, genetics, physiology, some industries (for example, the creation of waste-free technologies). Ecology serves as the main theoretical basis for the development of many sciences.

1. Ecological environmental factors and their characteristics.

The concept of the natural environment includes all the conditions of animate and inanimate nature in which an organism, population, natural community exists. The natural environment directly or indirectly affects their condition and properties. Ecological factor - a component of the natural environment that affects the state and properties of an organism, population, natural community; it is an element of the environment that can have a direct impact on a living organism at any stage of its development. There are three groups of factors:

1. abiotic factors - all components of inanimate nature, among which the most important are light, temperature, humidity and other climate components, as well as the composition of the water, air and soil environment;

2. biotic factors - interactions between different individuals in populations, between populations in natural communities;

3. anthropogenic factor - all the various human activities that lead to a change in nature as the habitat of all living organisms or directly affect their lives.

1. Types of relationships between organisms.

1. Symbiotic. Symbiosis is a form of existence of a population in which each species benefits from association with another species. The organisms included in the symbiosis are adapted to coexistence and often cannot live independently, and if some symbionts live separately, they cannot compete with other species.

a) cooperation - hermit crab and sea anemone;

b) mutualism - mycorrhiza - fungus root, lichen - mushroom algae (algae supply the fungus with sugars and receive mineral salts from the fungus, which it extracts from wood, rock, soil, etc.);
c) commensalism - a relationship in which one of the partners benefits, and for the other they are indifferent, i.e. the commensal uses a partner as a dwelling, a source of food, but does not harm the partner. Freeloading - pilot fish and shark; lodging - a refuge for some animals in the burrows of other animals, the bodies of other animals can be a refuge (slave - stuck, coelenterates on mollusk shells, epiphytes on tree trunks, algae, mosses, lichens, ferns, flowering plants);

2. Antibiotic.

a) predation - a relationship in which individuals of one species eat individuals of another (fox and hare, sundew, cannibalism). Predators, exterminating the most weakened individuals, maintain the composition and size of the population at an optimal level;

c) competition - populations belonging to different types, can compete with each other for vital resources: water, food, shelters, places for laying eggs, etc. Competition occurs when species have similar needs for living conditions, space, food. Less adapted organisms perish (sparrows and tits, herbivores, insects and mammals);

3. Indifferent: neutralism - squirrels and moose in the same forest, hydroid polyps on the shell of a mollusk.

1. The effect of environmental factors on living organisms.

Different environmental factors, such as temperature, humidity, food, act on each individual. In response to this, organisms develop various adaptations to them through natural selection. The intensity of the factors most favorable for life is called optimal or optimum. The optimal value of one or another factor for each species is different. Depending on the attitude to one or another factor, species can be warm and cold-loving (elephant and polar bear), moisture- and dry-loving (linden and saxaul), adapted to high or low salinity of water, etc.

endurance limit- the value of the intensity of the factor behind which the existence of life is impossible.
The optimum and limits of the body's endurance in relation to one of the environmental factors depend on the level of other factors. For example, when optimal temperature increases tolerance to unfavorable humidity and lack of food. On the other hand, the abundance of food increases the body's resistance to changes in climatic conditions. However, such mutual compensation is always limited, and none of the factors necessary for life can be replaced by another.

The ability of a species to reproduce individuals, to compete with others, will be limited by that of the factors that most strongly deviates from the optimal value for the species. If the quantitative value of at least one of the factors goes beyond the limits of endurance, then the existence of the species becomes impossible, no matter how favorable the other conditions are.

limiting factor- an environmental factor that goes beyond the endurance of the organism (beyond the permissible minimum or maximum). For example, the distribution of many animals and plants to the north is usually limited by a lack of heat, while in the south, the limiting factor for the same species may be a lack of moisture or the necessary food.

1. Forecasting and modeling.

To study relationships in ecosystems (natural communities), a variety of methods are used: experiment, long-term observation in nature, determining the number of individuals in populations, observing animal migration, etc.

For a more complete and deeper knowledge of wildlife, modeling is widely used - the creation of artificial ecological systems. In this case, mathematical data processing (mathematical modeling) is used. Modeling methods, if they correctly reflect the processes occurring in nature, make it possible to predict in what directions a given ecosystem will develop further, which is of great practical importance for many biogeocenoses (forest, meadow, swamp, lake).
Modeling and environmental forecasting are based on the principle of dividing complex ecosystems into separate, simpler components (subsystems) that are linked to each other by functional links of varying complexity. For example, in water system fish, phytoplankton, zooplankton, demersal animals and plants (benthos), etc. can be isolated. When studying aquatic ecosystems, aquariums are often used as models, into which various components from natural ecosystems are introduced and the forms of relationships between them are studied.

Ecosystem modeling methods are now increasingly used in ecology. They open up broad prospects for predicting the processes occurring in ecosystems and elucidating the effect of anthropogenic factors polluting it on the biosphere.

1. Seasonal phenomena in nature.

Seasonal periodicity is one of the most common phenomena in living nature. It is especially pronounced in temperate and northern latitudes. The seasonal phenomena of organisms are based on complex adaptive reactions of a rhythmic nature, which have been elucidated relatively recently.

winter calm- a complex physiological adaptation at a certain stage of development, in which the tissues of organisms contain many reserve nutrients, especially fats and carbohydrates, due to which reduced metabolic processes are maintained during wintering. The amount of water in tissues decreases, especially in seeds, winter buds of plants. Thanks to all these features, the resting stages are able to survive the harsh conditions of wintering for a long time. So, in plants (depending on the species), seeds, aboveground and underground parts with resting buds overwinter, and in some herbaceous plants - basal leaves. At different stages of development, winter dormancy occurs in insects. The malarial mosquito and hive butterflies overwinter in the adult insect stage, the cabbage butterflies in the pupal stage, and the gypsy moth in the egg stage.

biological rhythm– an annual cycle of intensive growth and development, reproduction, preparation for winter and wintering for each species in the course of evolution; periodically recurring changes in the intensity and nature of biological processes and phenomena. Match each period life cycle with the corresponding time of year is crucial for the existence of the species.
The main factor in the regulation of seasonal cycles in most plants and animals is a change in the length of the day. The reaction of organisms to the daily rhythm of lighting, i.e. on the ratio of daylight (length of the day) and the dark period of the day (length of the night), expressed in a change in the processes of growth and development - photoperiodism. Light conditions in nature, they have a distinct daily and seasonal periodicity, which is due to the rotation of the Earth. In connection with the daily rhythm of lighting, animals developed adaptations to a daytime and nighttime lifestyle.

The length of the day determines not only the onset of winter dormancy, but also other seasonal phenomena in plants. Thus, a long day contributes to the formation of flowers in most of our wild plants. Such plants are called long-day plants. Of the cultivated, these include rye, oats, most varieties of wheat and barley, and flax. However, some plants, mainly of southern origin, such as chrysanthemums, dahlias, need a short day to bloom. Therefore, they bloom with us only at the end of summer or autumn. Plants of this type are called short-day plants.

The influence of the length of the day on animals is strongly affected. In insects and mites, the length of the day determines the onset of winter dormancy. So, when caterpillars of cabbage butterflies are kept under conditions of a long day (more than 15 hours), butterflies soon emerge from pupae and a successive series of generations develops without interruption. But if the caterpillars are kept at a day shorter than 14 hours, then even in spring and summer overwintering pupae are obtained, which do not develop for several months, despite sufficient high temperature. This type of reaction explains why in nature in summer, while the day is long, several generations can develop in insects, and in autumn development always stops at the wintering stage.

In most birds, the lengthening day in spring causes the development of the gonads and the manifestation of nesting instincts. Autumn shortening of the day causes molting, the accumulation of spare fats and the desire to fly.

The change in the length of the day is always closely related to the annual course of temperature. Therefore, the length of the day serves as an accurate astronomical forerunner of seasonal changes in temperature and other conditions.

"The biological clock"- the ability of living organisms to navigate in time. Various developmental management techniques are used in year-round cultivation in artificial light. vegetable crops and ornamental plants, during winter and early forcing of flowers, for the accelerated production of seedlings. Pre-sowing treatment of seeds with cold achieves heading of winter crops at spring sowing, as well as flowering and fruiting in the first year of many biennial plants. By increasing the length of the day, it is possible to increase the egg production of birds on poultry farms.

Anabiosis- a temporary state of the body, in which life processes are slowed down to a minimum and there are no visible signs of life. Described in 1701. A. Levenguk. It is typical for viruses, bacteria, amphibians, reptiles, lichens, mosses, etc. It is used in practice for the manufacture of dry vaccines, cultures of bacteria, viruses, preservation of tissues and organs; increases the resistance of organisms to the influence of factors during space flights. Some rodents and turtles with the onset of a hot and dry period in the desert, when the vegetation burns out, fall into hibernation. At perennials often accompanied by shedding of leaves or complete death of ground parts, which occurs in many desert plants.

Poikilothermic (cold-blooded) animals- organisms whose body temperature depends on the ambient temperature (fish, amphibians, reptiles).

Homeothermic (warm-blooded) animals- able to maintain a constant body temperature (birds, mammals).
Front poll:

1. Expand the main tasks of ecology.

2. What environmental factors do you know?

3. What intensity of factors is called optimal?

4. What is a limiting factor? Give examples of a limiting factor specific to local conditions.

5. Describe the limit of endurance, give an example.

6. The essence of environmental forecasting and modeling. Give examples.

7. Describe and give examples of photoperiodism in plants and animals.

8. Describe and give examples of winter dormancy in plants and animals.

9. Describe and give examples of biological clocks in plants and animals.

10. Describe and give examples of suspended animation in plants and animals.

11. Describe and give examples of the biological rhythm in plants and animals.

12. Describe and give examples of poikilothermic and homeothermic organisms.

13. Types of relationships between organisms.

II. Ecosystem. Biogeocenosis. Agrocenosis
1.

Ecosystem. Types of ecosystems. Ecosystem properties.

2. Biogeocenosis. The main indicators of biogeocenosis.

3. The flow of energy.

4. Supply chains.

5. Ecological pyramids. Types of ecological pyramids.

6. Agrocenosis. Comparative characteristics agrocenosis and biogeocenosis.
1. Ecosystem. Types of ecosystems. Ecosystem properties.

Ecosystem- any combination of living organisms and their environment in a relationship. The term was proposed in 1935. Tansley.

Ecosystem types:

1. natural - swamp, forest, meadow, etc.;

2. artificial - aquarium, pond, fur farm, etc.

Ecosystem properties:

1. Self-reproduction - the ability of organisms to reproduce, the presence of food and energy in the environment, the reconstruction of the habitat by living organisms;

2. Integrity - the relationship of living organisms with each other and with the environment due to the flow of energy and matter;

3. Stability - the property of biogeocenoses to maintain balance when environmental conditions change, i.e. endure adverse conditions and maintain the ability to reproduce;

4. Self-regulation - the property of populations of organisms in a given biogeocenosis to limit their numbers.

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Seasons These are seasons that differ in weather and temperature. They change with the annual cycle. Plants and animals adapt perfectly to these seasonal changes.

Seasons on Earth

It is never very cold or very hot in the tropics, there are only two seasons: one is wet and rainy, the other is dry.

At the equator (on the imaginary midline) it is hot and humid throughout the year.

In temperate zones (outside the lines of the tropics) there is spring, summer, autumn and winter. Usually the closer to the North or South Pole the cooler the summer and the colder the winter.

Seasonal changes in plants

Green plants need sunlight and water to form nutrients and grow. They grow most in spring and summer or during the wet season. They tolerate winter or dry seasons differently. Many plants have a so-called rest period. Many plants store nutrients in thickened parts underground. Their aerial part dies, the plant rests until spring. Carrots, onions and potatoes are the type of nutrient storage plants that people use.

deciduous trees

deciduous trees, such as oak and beech, shed their leaves in autumn, because at this time there is not enough sunlight for the formation of nutrients in the leaves. In winter, they rest, and in spring new leaves appear on them.

evergreen trees always covered with leaves that never fall. To learn more about evergreen and shedding trees.

Some evergreen trees, such as pine and spruce, have long, thin leaves called needles. Many of the evergreen trees grow far north, where summers are short and cool and winters are harsh. Keeping their foliage, they can start growing as soon as spring arrives.

Deserts are usually very dry, sometimes there is no rain at all, and sometimes there are very short rainy seasons. Seeds germinate and give new shoots only in the rainy season. Plants bloom and produce seeds very quickly. They store nutrients

Seasonal changes in animals

Some animals, such as reptiles, reduce their activity and go to sleep to survive the cold or dry season. When it gets warmer, they return to an active lifestyle. Other animals behave differently, they have their own ways of surviving in harsh periods.

Some animals, such as the dormouse, sleep through the winter. This phenomenon is called hibernation. All summer they eat, accumulating fat so that in winter they can sleep without eating.

Most mammals and birds hatch their young in the spring, when there is plenty of food everywhere, so that they have time to grow and get stronger for the winter.

Many animals and birds undertake long journeys each year, called migrations, to places where there is more food. For example, swallows build nests in Europe in the spring, and fly to Africa in the fall. In the spring, when it becomes very dry in Africa, they return.

Caribou (called reindeer in Europe and Asia) also migrate, spending their summers above the Arctic Circle. Huge herds eat grass and other small plants where the ice melts. In autumn they move south to the evergreen forest area and feed on plants such as moss and lichen under the snow.

Seasonal changes in plant life.

Plants in winter

Plants in the winter forest seem completely lifeless to us. However, this impression is deceptive. Even in the most severe frosts, plant life does not stop. At this time, they rest, gain strength for the spring revival. “What we call the dream of nature,” wrote S. Pokrovsky, “is only a special form of life, full of deep meaning and significance.” This form of life of plant organisms is called a state of rest.
At this time, the metabolism of the plant is inhibited, and visible growth also stops. But life processes continue, albeit at a slower pace. For example, the starch accumulated over the summer turns into sugars and fats that feed the plant. In a state of winter dormancy, intensive activity of the educational tissue or meristem takes place in plants, which is transformed into new cells and tissues.
This period is very important for plants. It was at this time that the rudiments of leaves are laid in vegetative buds and elements of flowers - in flower buds. This allows the plant in the spring to quickly move to the active phase of life.

Therefore, for all perennial forms of plants, the dormant period is necessary condition normal growth during the growing season.
At different plants different duration of the dormant period. Some of them, such as honeysuckle, lilac, elderberry, buckthorn, are distinguished by a short dormant period. Their deep rest ends in October-November. Until January, a deep rest lasts near birch, poplar, hawthorn. The longest dormant period is observed in linden, spruce, pine, beech, and oak. A signal for rest is for them a decrease in the length of daylight hours. A change in the length of the day is perceived in plants by leaves, and in the absence of them, by buds. It is known that snow covering grass plants protects them from freezing. And what allows trees and shrubs with bare branches to "survive"? Why don't their buds and shoots die from the bitter cold? The survival of plants during the period of winter cold is facilitated by a change chemical composition cells. During the preparation of the plant for winter, sugars accumulate in its cell sap, lowering the freezing point. The more sugar the plant accumulates, the more successfully it will withstand the winter cold. It is known that after a plentiful harvest, apple trees often freeze out, because they did not have time to accumulate the required amount of sugars. Nutrients they have left mainly for the formation of fruits.
Plants that grew intensively in autumn, for example, due to prolonged warm weather or abundant nitrogen fertilization, also do not tolerate frost well. Nutrients were spent on plant growth, and not stored in reserve. In the spring, when the accumulated sugars begin to be used by the plant in its life processes, its frost resistance also falls. Therefore, spring, even small, frosts are more dangerous than harsh winter frosts.
Accumulated sugars allow plants, especially in broad-leaved forests, to begin their vital activity even under snow cover. Already in February, with bitter frosts under the snow, you can find pale yellow sprouts with folded leaves, and sometimes even buds. Since in such forests the soil does not freeze under the snow cover. The presence of a large amount of humus and snow cover create excellent thermal insulation. Due to this, the soil temperature here almost never drops below 0 degrees. Unfrozen moisture remains available for plants.
Intensive use of stored nutrients raises the temperature of the plant itself. Around him, sometimes even the snow melts. So in February, shoots of coltsfoot, laid back in the fall, begin to grow under the snow. If you dig up a plant at this time, you can see that a tiny cave has thawed around it in the snow cover.
Severe frosts are still cracking, and spring is already beginning under the snow

Plants in spring.

Cleared of snow small plot soil, let's see what is happening now under it in the forest. This should be done as carefully as possible so that, by removing the lower layers of snow, the plants under it are not damaged. We will see here, along with the overwintered evergreen stems of greenfinch (Galeobdolon luteum), wild hoof (Asarum europaeum) and hairy sedge (Carex pilosa), a number of tender, yellowish or barely green sprouts, breaking through the layer of last year's caked fallen leaves. In the perennial scilla (Mercurialis perennis), a common forest plant that forms a background in the grassy layer of the forest in summer, we will find large arched sprouts with buds under the snow. We will also find young stems with buds and leaves in lungwort (Pulmonaria officinalis), chistyak (Ficaria ranunculoides) and anemone (Anemone ranunculoides) - our usual spring plants, as well as in the musky adox (Adoxa moschatellina), goutweed and some others. These tender stems, with young, still folded leaves, differ sharply from the rough leathery parts of overwintered plants, so it is difficult to assume that they developed from autumn or from the previous summer and wintered in this form. In addition, in autumn, on the surface of the soil, one cannot find such large seedlings in all these plants, not to mention the developed leaves or even colored buds, which can often be found under the snow near the lungwort. Only in a perennial forest from autumn, under a thick layer of fallen leaves, you can see small arched, curved sprouts with a brush of barely noticeable rudimentary leaves.
Thus, it remains to be concluded that our spring plants have a remarkable ability to develop under the snow in winter. Leaving in the fall under the snow with dormant underground organs - rhizomes and tubers - they emerge from it already with developed stems, leaves, and often even with colored buds. In the forest during snowfall, young parts of spring plants break through the snow.

Plants in summer.

Summer is the time of the year when plants develop rapidly and perform all their vital functions, first of all, they form reproductive organs. Indeed, at this time of the year, most plants develop flowers, which then develop into fruits containing seeds from which new plants will develop.

That is why, in the summer months, plants require special care and attention; they need to be looked after regularly, following all the rules, carefully monitoring the temperature. Indeed, the heat of the summer months increases the evaporation that takes place with the help of leaves and flowers, and the earth dries quickly. The lack of water interferes with the proper circulation of nutrients, and if time does not intervene, the development of the plant may stop, which will lead to its death.

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Autumn is one of the most colorful seasons of the year. Autumn, like spring, amazes and attracts us with its continuous change - not a single day of autumn is like the rest.

The transition from the warm days of the end of summer to the first snow of winter takes place gradually during the autumn. In the apparent "dying" of autumn nature, sprouts of the next spring are hidden. The autumn period is of great importance for the life of plants and animals. Autumn is the transition period from summer to winter.

leaf fall

The beginning of the autumn coloring of trees can be considered the first sign of autumn. This majestic and colorful phenomenon of nature is associated with biological changes that occur in almost all wild trees during the cold periods of the year. The foliage falls and thus allows the plants to rest, prepare for a long winter hibernation, when all life processes inside the tree stop, and the juices stop circulating. Without leaves, trees consume much less water and do not accumulate much snow on their branches during snowfalls. This means that the risk of mechanical damage is reduced. In addition, along with the leaves, the plants shed all kinds of pests, which then die during the period when the cold sets in. It can be said that autumn changes in nature, they begin with leaf fall. But this is in wildlife (after all, trees are also living beings with the ability to breathe and grow). And how are the autumn changes in inanimate nature associated with the near onset of cold weather?

Indian summer is a short period, usually ending with the onset of October. The first signs of inclement weather are already appearing. Fogs, thick, sticky, resembling milk in appearance, fill the autumn nature with dampness and a rotten smell. In its essence, fog is a thick cloud, which, as a result of a temperature drop, forms at the very surface of the soil. As soon as it warms up, the fog will dissipate. Moisture will fall on withered grass and foliage in the form of frost.

The topic of autumn changes in inanimate nature also includes such a phenomenon as frost. In essence, these are small particles of dew frozen in the form of snowflakes. They cover all surfaces with a thin, uneven prickly layer. This suggests that the first frosts and negative temperatures appeared in the atmosphere.

winds and clouds

In autumn, the cold front of the atmosphere brings with it colder air masses. The winds react to this and change their direction, intensify, bringing bad weather and precipitation. This time of year sometimes becomes slushy and long, causing autumnal changes in nature.

Ice drift and ice

At the end of November, it happens that the air temperature drops to negative values. The water surface of various reservoirs is bound by the first crusts of ice. This most often occurs in ponds and lakes, where there is almost no current. The ice is not yet completely strengthened, so the wind and currents carry it away, forming the so-called autumn ice drift. The ice that covers the soil in the middle and at the end of autumn is formed during a light frost, which prevents the rain from turning into snow. The earth has not yet cooled down enough to cover itself with a blanket of snow, a harbinger of severe frosts.

Autumn changes in wildlife

In plants, autumn is a thorough preparation for winter period when all of them (living in natural conditions) fall into hibernation: vital activity and the exchange of juices decreases many times.

Insects with the onset of cold weather hide and hibernate. This is a defensive reaction to lower temperatures. Many insects (such as flies or beetles) crawl into cozy crevices and at first glance appear to be dead. But it's not. With the onset of spring, they will come to life and fly again.

Cold-blooded animals "sleep" as a result of the fact that they cannot maintain the temperature necessary for existence. Snakes, frogs, reptiles and amphibians all hibernate in late autumn.

At the very beginning of autumn, birds prepare for flights to warmer climes. Then their flight begins. Wintering birds do not fly away and feed intensively in the autumn forests.

Some mammals also hibernate in late autumn and early winter. But this is more likely due not to the onset of cold weather, but to the lack of food supply for them in winter. These animals include: bear, badger, marmot, hedgehog, some rodents (gopher, hamster, dormouse).

Wintering mammals intensively accumulate weight in order to use their own fat for heating and nutrition during the winter cold.

Thus, the animal world is preparing for the approach of the winter cold period, reacting differently to autumn changes in nature.

K. Paustovsky said beautifully about autumn:

“More than all the seasons, I love and regret autumn, perhaps because she has very little time for her rustling and flying life.”

AUTUMN CHANGES

IN NATURE

Prepared by:

Minkin Egor

Student 2 "A" class

For the comprehensive development of preschoolers in kindergarten and younger schoolchildren, it is imperative to pay attention to the natural changes of the seasons: spring, summer, autumn, winter. For example, with the beginning of autumn and the new school year you can conduct a lesson "Autumn changes in nature", clearly explaining the topic of training in the park on walks or in the classroom using the material collected in advance. Older children keep a calendar of weather changes, drawing icons and making comparisons with previous years. It records autumn changes in nature (pictures and a herbarium are attached). On the topic of the lesson, the children should pay attention to the following points.

Golden autumn

In central Russia, autumn, indeed, is “the charm of the eyes,” as the poet said. The heat and stuffiness of summer is changed by a slight coolness. The days are getting shorter and the nights are getting longer and darker. They are the first to react to these autumn changes in nature, turning yellow and red, then slowly fly around, covering the entire area with a multi-colored carpet. There comes a period of golden Indian summer, when nature still pleases with a moderate sun, when late fruits ripen, filled with both sweetness and aroma, but the nights are already getting colder and colder.

leaf fall

And the colorful phenomenon of nature is associated with biological changes that occur in almost all wild trees during the cold periods of the year. The foliage falls and thus allows the plants to rest, prepare for a long winter hibernation, when all life processes inside the tree stop, and the juices stop circulating. Without leaves, trees consume much less water and do not accumulate much snow on their branches during snowfalls. This means that the risk of mechanical damage is reduced. In addition, along with the leaves, the plants shed all kinds of pests, which then die during the period when the cold sets in. We can say that autumn changes in nature begin with leaf fall. But this is in (after all, trees are also living beings with the ability to breathe and grow). And how are the autumn changes in inanimate nature associated with the near onset of cold weather?

mists

Indian summer is a short period, usually ending with the onset of October. The first signs of inclement weather are already appearing. Fogs, thick, sticky, resembling milk in appearance, fill the autumn nature with dampness and a rotten smell. In its essence, fog is a thick cloud, which, as a result of a temperature drop, forms at the very surface of the soil. As soon as it warms up, the fog will dissipate. Moisture will fall on withered grass and foliage in the form of frost (if the ground has already cooled down enough).

Frost

The topic of autumn changes in inanimate nature also includes such a phenomenon as frost. In essence, these are small particles of dew frozen in the form of snowflakes. They cover all surfaces with a thin, uneven prickly layer. This suggests that the first frosts and negative temperatures appeared in the atmosphere.

winds and clouds

In autumn, the cold brings with it colder winds. The winds react to this and change their direction, intensifying, bringing bad weather and precipitation. This time of year sometimes becomes slushy and long, causing autumnal changes in nature.

In turn, cumulus rain clouds bring in a huge amount of precipitation. If the temperature changes sharply enough, then you can feel strong winds at the beginning of autumn, see and feel the rains with snow, as a result of the appearance of a cold cyclone.

Ice drift and ice

At the end of November, it happens that the air temperature drops to negative values. The water surface of various reservoirs is bound by the first crusts of ice. This most often occurs in ponds and lakes, where there is almost no current. The ice is not yet completely strengthened, so the wind and currents carry it away, forming the so-called autumn ice drift.

The ice that covers the soil in the middle and at the end of autumn is formed during a light frost, which prevents the rain from turning into snow. The earth has not yet cooled down enough to cover itself with a blanket of snow, a harbinger of severe frosts.

Observing the autumn changes in nature, one can learn how the transition to the winter period of life, cold and snowy, is being prepared. When everything around seems to freeze until the next spring and the onset of warm days.

Autumn changes in wildlife

• We already talked about leaf fall in trees and its significance for the life of plants at the beginning of the article. It should be emphasized that trees also belong to wildlife, as they live and die, breathe and give offspring. In plants, autumn is a thorough preparation for the winter period, when all of them (living in natural conditions) fall into hibernation: vital activity and the exchange of juices decrease many times over.
• Insects with the onset of cold weather hide and hibernate. This is a defensive reaction to lower temperatures. Many insects (such as flies or beetles) crawl into cozy crevices and at first glance appear to be dead. But it's not. With the onset of spring, they will come to life and fly again.
• Cold-blooded animals "sleep" as a result of the fact that they cannot maintain the temperature necessary for existence. Snakes, frogs, reptiles and amphibians all hibernate in late autumn.
• At the very beginning of autumn, birds prepare for flights to warmer climes. Then their flight begins. Wintering birds do not fly away and feed intensively in the autumn forests.
• Some mammals also hibernate in late autumn and early winter. But this is more likely due not to the onset of cold weather, but to the lack of food supply for them in winter. These animals include: bear, badger, marmot, hedgehog, some rodents (gopher, hamster, dormouse).
• Wintering mammals intensively accumulate weight in order to use their own fat for heating and nutrition during the winter cold.

Thus, the animal world is preparing for the approach of the winter cold period, reacting differently to autumn changes in nature.

Autumn is one of the most colorful seasons of the year. Autumn, like spring, amazes and attracts us with its continuous change - not a single day of autumn is like the rest. The transition from the warm days of the end of summer to the first snow of winter takes place gradually during the autumn.

In the apparent "dying" of autumn nature, sprouts of the next spring are hidden. The autumn period is of great importance for the life of plants and animals. Autumn is the transition period from summer to winter.

leaf fall

The beginning of the autumn coloring of trees can be considered the first sign of autumn. This majestic and colorful phenomenon of nature is associated with biological changes that occur in almost all wild trees during the cold periods of the year.

The foliage falls and thus allows the plants to rest, prepare for a long winter hibernation, when all life processes inside the tree stop, and the juices stop circulating. Without leaves, trees consume much less water and do not accumulate much snow on their branches during snowfalls.

This means that the risk of mechanical damage is reduced. In addition, along with the leaves, the plants shed all kinds of pests, which then die during the period when the cold sets in. We can say that autumn changes in nature begin with leaf fall. But this is in wildlife (after all, trees are also living beings with the ability to breathe and grow).

And how are the autumn changes in inanimate nature associated with the near onset of cold weather?

Indian summer is a short period, usually ending with the onset of October. The first signs of inclement weather are already appearing.

Fogs, thick, sticky, resembling milk in appearance, fill the autumn nature with dampness and a rotten smell. In its essence, fog is a thick cloud, which, as a result of a temperature drop, forms at the very surface of the soil. As soon as it warms up, the fog will dissipate. Moisture will fall on withered grass and foliage in the form of frost.

The topic of autumn changes in inanimate nature also includes such a phenomenon as frost.

In essence, these are small particles of dew frozen in the form of snowflakes. They cover all surfaces with a thin, uneven prickly layer. This suggests that the first frosts and negative temperatures appeared in the atmosphere.

winds and clouds

In autumn, the cold front of the atmosphere brings with it colder air masses.

The winds react to this and change their direction, intensify, bringing bad weather and precipitation. This time of year sometimes becomes slushy and long, causing autumnal changes in nature.

Ice drift and ice

At the end of November, it happens that the air temperature drops to negative values. The water surface of various reservoirs is bound by the first crusts of ice. This most often occurs in ponds and lakes, where there is almost no current. The ice is not yet completely strengthened, so the wind and currents carry it away, forming the so-called autumn ice drift. The ice that covers the soil in the middle and at the end of autumn is formed during a light frost, which prevents the rain from turning into snow.

The earth has not yet cooled down enough to cover itself with a blanket of snow, a harbinger of severe frosts.

Autumn changes in wildlife

In plants, autumn is a thorough preparation for the winter period, when all of them (living in natural conditions) fall into hibernation: vital activity and the exchange of juices decrease many times over.

Insects with the onset of cold weather hide and hibernate.

This is a defensive reaction to lower temperatures. Many insects (such as flies or beetles) crawl into cozy crevices and at first glance appear to be dead. But it's not. With the onset of spring, they will come to life and fly again.

Cold-blooded animals "sleep" as a result of the fact that they cannot maintain the temperature necessary for existence.

Snakes, frogs, reptiles and amphibians all hibernate in late autumn.

At the very beginning of autumn, birds prepare for flights to warmer climes. Then their flight begins. Wintering birds do not fly away and feed intensively in the autumn forests.

Some mammals also hibernate in late autumn and early winter.

But this is more likely due not to the onset of cold weather, but to the lack of food supply for them in winter. These animals include: bear, badger, marmot, hedgehog, some rodents (gopher, hamster, dormouse).

Wintering mammals intensively accumulate weight in order to use their own fat for heating and nutrition during the winter cold.

Thus, the animal world is preparing for the approach of the winter cold period, reacting differently to autumn changes in nature.

K. Paustovsky said beautifully about autumn:

“More than all the seasons, I love and regret autumn, perhaps because she has very little time for her rustling and flying life.”

AUTUMN CHANGES

IN NATURE

Prepared by:

Minkin Egor

Student 2 "A" class

Every autumn, the animals in the forest carefully prepare for the difficult period of the year. They prepare food in their pantries, insulate burrows, change summer coats for winter ones.

Who flew away and who stayed

Those birds that cannot feed themselves in winter fly away from our places in autumn.

Most of the seeds fall to the ground and end up under the snow.

And many birds feed on the seeds of grasses, trees, shrubs. For some birds, the main food is insects; with the onset of cold weather, they disappear: some die, others hide. Frogs, toads, fish become inaccessible to birds.

It is difficult to get mice and other small animals that have taken refuge under deep snow cover or hibernated.

So cranes, geese, seagulls are drawn in shoals, strings to warm lands.

Birds that stay over the winter in our forests stock up in autumn. The jay selects the largest acorns and hides them under the moss, under the roots, and digs them into the foliage.

The nuthatch picks up hazel nuts, linden nuts and maple lionfish, drives them into cracks in tree bark at high altitude. Curious stocks are made by little owls. They hide dead mice and small passerine birds in hollows.

Those who cannot fly

Trees cannot part with the trunk and branches for the winter and hide underground.

They act differently: they shed their leaves. Leaves need a lot of moisture. And the water in the soil freezes in winter and the roots cannot pump it out. In addition, the leaves in winter would only harm the tree. Branches and branches would break under the weight of snow adhering to them. It doesn’t hurt to lose leaves: there are no wounds on the branches from fallen leaves, if in summer the petioles of the leaves are firmly connected to the branches, because nutrients move along them, then in the fall, where the petiole is attached to the branch, a special cork layer grows and gradually, like a partition, separates petiole from a branch.

Herbs hide under the ground

These tricksters part with the above-ground part of the plant.

The main thing for them is to save the underground pantry - a rhizome, tuber or bulb, in which nutrients accumulated in the summer. In the spring, these reserves will help to quickly revive the stem and leaves.

About the inhabitants of the forest

By winter, the squirrel makes a large, warm hollow, with tow poked into all the walls, squirrel hair and down.

Dried mushrooms lie in one corner, nuts in another, apples in the third. Beavers strengthen dams and repair huts. Bears in dense forest thickets are looking for a place for a den, where they will lie down to hibernate from the beginning of winter.

A hungry fox wanders along the banks of rivers and streams, looking out for young inexperienced ducks. Insects: beetles, spiders, flies clog into cracks in the bark of trees and bushes, hide under foliage, winter in dry stumps and snags.

"Chilled" worms and ... grain intervention

Moles make deep underground passages and hide earthworms in them: the mole bites the head of its prey and the worms cannot move, although they remain alive, so the mole always has fresh food in winter.

The gray vole, living in the field, stores in its burrows two or three kilograms of grains of wheat, millet, rye, and as a seasoning for this, the leaves and roots of many herbs.

And the bank vole harvests nuts, acorns, maple lionfish, linden nuts, and various berries.

What are people doing at this time?

For example, for the tenants of the Charyshsky forestry, and there are more than 50 of them, as Peter Kisly, the forester of the Charyshsky forestry, told us, the autumn time is especially troublesome.

Hay is harvested from July to September, and when the road "gets up" - they are taken out. Almost all of the cattle have already been placed in stalls with the first snow. But the horses continue to graze on the snow, raking it and taking out dry grass. And so on until spring. In spring, the breeding stock of horses is placed in stalls, and the young remain in the forest.

Beekeepers, according to tenant Denis Kucherenko from Solton forestry, make bees for the winter with the first frosts, by the way, some bees hibernate in the wild, while others - in omshaniki.

Ekaterina Ivanova, director of the Priobye hunting farm, says:

“Wild animals are getting ready for winter, and so are we humans. We prepare food so that during the winter "crisis" wild animals can feed on our sites.

If we talk about long-term observations of animals, then most often they change their “clothes” for the winter, there are many features in their behavior. Still black earth, and the hare is already white. The boar grows an undercoat impregnated sebaceous glands won't get wet in winter! Boars live together for years in the same territory and winter here, it is not common for them to make "housing" where they have to - they dug a ditch in the swamp to a warm melted place and this is their home.

The elk is also not picky, where the night found, there is his home. Moose have a rut in autumn, call females, scratch their antlers on a tree, thus shedding them.

The lynx becomes even more beautiful in winter - the fur coat becomes white. If you meet her, you are amazed, she will never cowardly run away, this huge cat will proudly turn around and worthily retire with her family from your path. But in general, in the fall, animals have a mating season everywhere, and in the spring there will be babies, whoever has how many - a wild boar has up to 15 pieces, an elk has one or two calves, a lynx has one or two kittens.

FORESTER'S PAGE

Changes in nature in autumn

Leaf fall is a remarkable phenomenon of nature, justified with biological point vision. Fallen leaves give the trees a chance to rest and prepare for their long winter hibernation. Without leaves, trees consume less water, accumulate less snow on their bare branches, which means that the risk of mechanical damage is reduced. With leaves, trees shed all harmful insects that will die in winter time of the year.

It is during the leaf fall that the period of Indian summer begins. The last maximum warm temperatures delight with moderate sun. Late fruits ripen, which are filled with sweetness and a special aroma. At night, you can already feel the breath of close cold weather, but during the day it is very beautiful and peaceful.

Indian summer does not last long, starting on the 20th of September, it ends with the onset of the next month, it is replaced by the first serious signs of autumn bad weather. A thick fog descends on the ground, sticky and milky, filling the air with stale dampness.

Why do trees need leaf fall?

Leaves are the lungs of the tree. Without them, photosynthesis is impossible - a process that is both respiration and nutrition for a plant at the same time. Photosynthesis works best when the tree has enough light and heat.

Therefore, with the first rays of the spring sun, they begin to dissolve young sticky leaves.
But in the winter cold, the leaves become a burden. And the first reason that prompts the tree to get rid of the lush crown is the lack of moisture and cold. in winter upper layer soil freezes, and it becomes impossible to extract water from it. The leaves evaporate a very large amount of moisture. If the plant had not dropped them in the winter cold, it would have died of thirst.

Another good reason to get rid of foliage is winter precipitation.

It happens that even without leaves, snow and ice, sticking to branches, break a tree with their mass. And imagine how much such a load would accumulate on the leaves! Few trees would survive until spring intact.

The plant begins preparing for the autumn leaf fall ahead of time. In August-September, a smooth partition grows on the base of the leaf - the so-called cork layer. Increasing in volume, it gradually separates the petiole from the branch. For some time, the leaf is still held by "water-bearing" vessels, but it is worth flying light wind and it falls off.

A sure sign that leaf fall will begin soon is yellowing or reddening of the foliage.

This is due to the fact that chlorophyll, a substance involved in the process of photosynthesis and coloring the leaf green, does not have time to recover from the lack of daylight. It is gradually replaced by other substances, which is why the leaf changes color.

At its core, fog is a thick cloud that has formed at the very surface of the earth. A sharp temperature drop in the early morning hours raises moisture into the air, concentrating it in it.

Once the temperature rises, the fog will dissipate and the moisture will fall back to the ground, covering the withered grass with a layer of frost if the ground is cool enough.

Hoarfrost is particles of frozen dew.

They look like prickly snowflakes, covering all surfaces with an uneven, prickly layer. As a rule, the appearance of a light ice cover indicates that negative temperatures and the first frosts have appeared.

As temperatures drop, a cold front arrives, bringing cold air mass. Winds change their directions and intensify, bringing with them precipitation and bad weather. If this happens gradually, then the autumn turns out to be slushy, protracted.
Cumulonimbus clouds carry a large amount of precipitation. If the climate change occurs abruptly, then it is often possible to see rains with snow, strong winds, and the appearance of various cold cyclones even at the beginning of autumn.

Closer to December, the air temperature drops to low negative levels, which already bind the water surface with the first crust of ice. The ice is still not quite strong, so the water carries it downstream, forming an autumn ice drift.

In mid-autumn, ice covers the ground, it forms only under the condition of a light frost, which prevents the rain from turning into snow. The air is already cold, but the ground has not yet cooled down enough to cover everything around with a white blanket of snow - the first harbinger of a severe frost.
Thus nature prepares the transition to winter, long and protracted, snowy and cold.

Frosty breath is already felt in cold nights, and bad weather and slush rebuild all living things around, put it into hibernation, helping to cope with the approaching cold.

Fog is a collection of condensation products. A huge number of water droplets or ice crystals come together and form a cloud near the surface of the earth. Sometimes it is so dense that nothing is visible at arm's length.

Physical principles of fog formation

Fog is formed due to the contact of cold air with warm air at a relative humidity of more than 85%.

But in settlements, fog often occurs even with low humidity. This occurs as a result of the condensation of water vapor, which appears during the combustion of fuel (in furnaces, car engines, etc.).

Seasonality in fogging

Fog can be at any time of the year. This is a common occurrence in the lowlands, above water bodies, in the mountains. In the autumn-winter period, fog occurs most often. High humidity prevails during these months. Air temperature tends to change abruptly. Therefore, the flows of warm and cold air actively move above the ground.

The duration of fogs in the time interval can vary from several tens of minutes to a day or even more.
Hoarfrost - a type of precipitation, which is ice crystals, is formed in the process of sublimation of atmospheric moisture on horizontal and subhorizontal surfaces.

How frost is formed

The frost formation mechanism is a combination of condensation and crystallization processes. Atmospheric water vapor condenses on surfaces cooled to negative temperatures, lower than the air temperature, followed by freezing.

As a rule, this phenomenon occurs in the cold season, more often in autumn and spring, at night or in the early morning as a result of frosts.

Usually, the appearance of frost is preceded by warming, which contributes to an increase in humidity, followed by a sharp cooling. Most likely, frost forms on surfaces with low thermal conductivity - earth cover, wood, grass and other similar ones.

Windless weather and light wind are favorable conditions for the formation of frost crystals. Strong wind On the contrary, it hinders the process.

One of the interesting forms of hoarfrost - hoarfrost flowers, are formations of ice crystals arranged in separate groups, in a form resembling flowers, leaves, trees and other unusual forms.

Composition "What can be seen in the autumn forest? .."

One autumn day, the guys and I gathered in the forest just to take a walk, breathe fresh air, chat, in general, relax.

It was sunny weather. It was warm like in summer. We walked with a sense of calmness, ease, with a sense of accomplishment - behind us a working week. We were driven by a quiet and warm breeze. He caressed our cheeks. And we hurried into the forest, wanting to see a miracle.

Indeed, in the autumn you can see so many interesting things in the forest. Here on our way we met a clearing of bright red fly agaric. On the withered autumn grass, they seemed like bright lights that warmed our hearts.

In addition, all these mushrooms were different shapes: one looks like a pink saucer with a burgundy border, the other looks like a bright and juicy tomato (oh, I would like to eat it!), the third stuffed the little red cap up to his ears and sits, does not move. And what skirts on immaculately white legs are just a feast for the eyes! They left the clearing with a feeling of regret. Dangerous beauty! Suddenly, we stumbled upon a transparent cobweb, which simply "hung" in the air and did not hold on to anything. She shone in the sun, and her thin threads shimmered in different colors.

There was no spider on it, but many small flies remained forever in this trap. Such deadly beauty also happens only in autumn!

Quiet in the forest. Only the rustle of leaves, the whisper of blades of grass, and suddenly a piercing cry is heard.

Who is this? Beast, bird, man? Looked around. Nobody here. Only green firs stand guard, guarding the peace of the forest inhabitants, tall pines whisper about something there, at the very top, elder bushes beckon with crimson clusters. A nimble lizard caught our eye.

All black herself. She quickly ran away to hide from us. We laugh merrily and envy her a little, because she can run wherever she wants.

And in the distance you can see small mountain ash. Who planted them here? The stems are thin. The trees bend both from the wind and from the neighborhood with older trees. But they don’t give up: they bend down and stand up again. The leaves turned red, and in some places even green. A real mosaic! Yes, if a birch grows nearby! This is just a miracle!

Our attention was also attracted by the last flowers as an echo of the past summer. They seemed so sweet and kind to us. I wanted to come up, stroke, talk. Here is a purple bell lost in the thicket of the forest.

And this raspberry clock bowed its heads to the ground. One burdock stands firmly on its feet and clings to everyone passing by.

We didn't notice how two hours had already passed.

Rested in the autumn forest body and soul. I did not want to go home from this fabulous kingdom at all. All the way back, we remembered all the wonders of autumn nature again and again, the meeting with which will remain in our hearts and in photographs for a long time.

Seasonal periodicity is one of the most common phenomena in living nature. It is especially pronounced in temperate and northern latitudes. Outwardly simple and familiar to us seasonal phenomena in the world of organisms are based on complex adaptive reactions of a rhythmic nature, which have been elucidated relatively recently. As an example, consider the seasonal periodicity in the central regions of our country. Here, the annual temperature variation is of key importance for plants and animals. The period favorable for life lasts about six months.

Seasonality is a common phenomenon in wildlife caused by changes in inanimate factors during the year. This phenomenon is especially pronounced in the regular change of seasons in temperate and northern latitudes. In spring and summer, most animals breed, give birth, and by the end of summer and autumn they are preparing to endure the conditions of winter.

The signs of spring appear as soon as the snow begins to melt. Some willows, alders, and hazels are blooming before their leaves have even opened; on thawed patches, even through the snow, sprouts of the first spring plants make their way; migratory birds arrive; overwintered insects appear.

In the middle of summer, despite the favorable temperature and abundance of precipitation, the growth of many plants slows down or stops completely. The number of flowering plants is decreasing. Bird breeding ends. The second half of summer and early autumn is the period of ripening of fruits and seeds in most plants and the accumulation of nutrients in their tissues. At this time, signs of preparation for winter are already noticeable. In birds and mammals, the autumn molt begins, migratory birds gather in flocks.

Even before the arrival resistant frost in nature, a period of winter dormancy begins.

Winter dormancy

Winter dormancy is not just a developmental arrest caused by low temperatures, but a very complex physiological adaptation. In each species, the state of winter dormancy occurs only at a certain stage of development.
Wintering stages of plants and animals have many similar physiological features. Significantly reduced the intensity of the exchange. The tissues of organisms that are in a state of winter dormancy contain many reserve nutrients, especially fats and carbohydrates, due to which reduced metabolic processes are maintained during wintering. Usually the amount of water in tissues decreases, especially in seeds, winter buds of plants. Thanks to all these features, the resting stages are able to survive the harsh wintering conditions for a long time.

Adaptations of cold-blooded animals for wintering

Cold-blooded animals (eg, insects, amphibians, reptiles) endure the winter in an inactive state of winter dormancy. In their body, changes occur that begin well in advance in the summer. By autumn, their nutrient reserves increase, due to which metabolism is maintained at a slow pace. The amount of water in their cells decreases. Despite this preparedness, many cold-blooded animals hibernate in shelters where the harsh conditions of winter are less pronounced.

Adaptations of warm-blooded animals for wintering

Warm-blooded animals are birds and mammals. They have less ability to hypothermia than cold-blooded. A constant body temperature is ensured by their high metabolic rate. To maintain the temperature at the same level, they have such features as heat-insulating covers (down, feather, hair), fatty deposits, etc. To reduce heat transfer in winter conditions, they have an autumn molt - a change of summer fur in mammals and plumage in birds to a thicker, winter one.

Warm-blooded animals do not go into winter dormancy if they can feed themselves in the winter. Mammals that are unable to forage in winter conditions hibernate. Hibernation is a state of reduced vital activity that occurs in warm-blooded animals in cases where food becomes inaccessible and it is impossible to maintain high activity and intensive metabolism. Before hibernation, animals accumulate nutrients in the body, mainly fats up to 40% of body weight, and settle in a shelter.

Birds that are not able to provide themselves with food in winter conditions fly away to warmer climes, where they find abundant food.

The study of seasonal phenomena

The laws of periodic seasonal changes in the life of plants and animals are studied by the science of phenology; observations of the onset of these phenomena are called phenological. The essence of these observations is to follow the course of seasonal phenomena and record the dates of their onset, and in some cases their end. Based on long-term phenological observations, local lore organizations compile calendars of nature, which reflect the time of the onset of seasonal phenomena in a particular area.

Trees in autumn. Photo: Mike Nielsen

The Importance of Studying Seasonal Phenomena

The need to study seasonal phenomena arose in man a very long time ago in connection with the development of agriculture, fishing, and hunting.

By annually determining the dates of the onset of seasonal changes and comparing them with the time of agricultural work, it is possible to establish the best time for tillage, sowing seeds, and thereby increase the yield. So, for example, according to the data of the K. A. Timiryazev agrobiological station, the largest yield of cucumbers is obtained when they are sown during the flowering of purple lilac and yellow acacia. best term sowing turnip - the time of flowering aspen.

Parallel observations of the course of development of plants and insects that feed on them facilitate the establishment of deadlines for the control of pests of cultivated plants.

Phenological observations provide rich factual material that serves as proof of Charles Darwin's theory of natural selection and helps to understand the essence of the basic law of biology - the unity of the organism and the conditions of life necessary for it. Observations broaden the horizons of a person, increase his interest and love for nature. At the same time, they do not require sophisticated equipment and are available to anyone.



Seasonal changes in animal life

Seasonality is a common phenomenon in wildlife caused by changes in inanimate factors during the year. This phenomenon is especially pronounced in the regular change of seasons in temperate and northern latitudes. In spring and summer, most animals breed, give birth, and by the end of summer and autumn they are preparing to endure the conditions of winter.

Adaptations of cold-blooded animals for wintering.

Cold-blooded animals (eg, insects, amphibians, reptiles) endure the winter in an inactive state of winter dormancy. In their body, changes occur that begin well in advance in the summer. By autumn, their nutrient reserves increase, due to which metabolism is maintained at a slow pace. The amount of water in their cells decreases. Despite this preparedness, many cold-blooded animals hibernate in shelters where the harsh conditions of winter are less pronounced.

Adaptations of warm-blooded animals for wintering. Warm-blooded animals are birds and mammals. They have less ability to hypothermia than cold-blooded. A constant body temperature is ensured by their high metabolic rate. To maintain the temperature at the same level, they have such features as heat-insulating covers (down, feather, hair), fatty deposits, etc. To reduce heat transfer in winter conditions, they have an autumn molt - a change of summer fur in mammals and plumage in birds to a thicker, winter one.

Warm-blooded animals do not go into winter dormancy if they can feed themselves in the winter. Mammals that are unable to forage in winter conditions hibernate. Hibernation is a state of reduced vital activity that occurs in warm-blooded animals in cases where food becomes inaccessible and it is impossible to maintain high activity and intensive metabolism. Before hibernation, animals accumulate nutrients in the body, mainly fats up to 40% of body weight, and settle in a shelter.

Birds that are not able to provide themselves with food in winter conditions fly away to warmer climes, where they find abundant food.

Regulation of seasonal changes in animal life.

The presence of links between seasonal changes in the life of animals and the seasonal course of temperature is striking. In the spring, when it gets warm, migratory birds arrive, mammals wake up from hibernation, cold-blooded animals come out of a state of stupor. In autumn, with the onset of cold weather, they have the opposite. However, the preparation of animals for wintering begins in the summer, when there are favorable temperature conditions for them. This means that it is not temperature that regulates seasonal changes in the body. It has been established that the main regulating factor of complex seasonal changes in the life of animals and plants is not a change in annual temperatures, but regular annual changes in the length of the day, not subject to random fluctuations, such as temperature. Changes in the length of the day during the year serve as a signal that determines future seasonal changes in the body.