Plant life in nature in spring. Interesting information about flowering Many plants are pollinated with the help of the wind.

There are many classifications of plants, but one of the main ones is the one based on the nature of pollination. From this point of view, crops are divided into several large groups: wind-pollinated, pollinated by animals (mainly insects, so we will call such plants insect-pollinated) and water (hydrophilia, is observed infrequently, therefore it will not be considered). Representatives of all these groups have cross-pollination, that is, the transfer of pollen with outside help (the opposite of self-pollination).

To find out what wind-pollinated plants are, you must first understand the features and differences of each group.

Plants, as we have just found out, can be pollinated both from the wind and with the help of insects.

Wind pollinated crops, their signs

To begin with, plants that are part of this group (they are also called anemophilous) under certain circumstances can be pollinated by insects, although this does not happen often. Such plants are distinguished by numerous small branches, as well as by the fact that they are able to produce a large amount of pollen (each specimen produces several million pollen grains). In many crops (such as, for example, mulberry or hazel), the formation of flowers begins even before the leaves bloom.

The flowers themselves are often inconspicuous and collected in small inflorescences. In a panicle, for example, this is a complex spikelet. The inflorescence produces many light and small pollen grains.

Note! As a rule, crops pollinated by the wind grow in groups. Moreover, wind-pollinated plants include not only trees (birch, alder, etc.), but also grasses (sedge, timothy) and bushes.

Insect pollinated crops

A distinctive feature of these plants (by the way, they are also called entomophilous) is that they bloom after the leaves appear. An important role is played here temperature conditions: when the temperature rises, then there are insects that carry pollen. In addition, all insect-pollinated crops have nectaries.

The most common representatives of the group include willow. Willow flowering can be observed both before and after foliage formation. But early flowering has nothing to do with wind pollination - plants resort to such a “reception” solely to fight competitors for pollinating insects.

Table. Comparative characteristics wind and insect pollinated crops

Flower Features	anemophilous plants	entomophilous plants
Nectar	Absent
Corolla	Missing (or, alternatively, looks nondescript)	Bright
Smell	Absent	Available to most of the representatives
The location of the stamens	Open (anthers are located on large threads)	Inside the flowers
Pollen	Small, dry, large	Sticky and large, in small quantities
Stigmas of pistils	Large	small

Anthers of anemophilous cultures are carried outside the flowers. The stigmas of the pistils are large and “shaggy”, which allows them to catch dust particles that fly in the air. Also, such plants have special adaptations, so to speak, due to which pollen is not wasted, but falls mainly on the stigmas of other members of its species.

And now let's get acquainted in more detail with the features of crops pollinated by the wind.

Features of anemophilous plants

All representatives of this group are characterized by the following features:

• inconspicuous or inconspicuous flowers (explained by the fact that they should not attract insects);
• small and dry pollen grains;
• long threads on which anthers hang.

Now more. main feature of all wind-pollinated crops - this is the unattractiveness of flowers, manifested in the absence of nectar, smell and bright colors. At the same time, pollen grains that develop in large quantities, are extremely small: the average weight of one grain of dust is 0.000001 mg. Let's give a small comparison: a speck of pumpkin dust - a plant pollinated by bees - weighs a thousand times more, i.e., about 0.001 mg. Only one inflorescence horse chestnut able to form 42 million grains, while the inflorescence of rye is ten times smaller (4 million 200 thousand). The peculiarities of the pollen of anemophilous plants include the fact that, being completely devoid of adhesive substances, it often also has a smooth surface.

Note! Wind pollinated crops do not have nectar, but they are often visited by insects that feed on pollen. However, these insects play only a minor role as vectors.

What plants can be wind pollinated?

Below are representatives of wind-pollinated crops.

1. Birch family. The most common member of the family in Europe and Asia is the warty birch, which blooms in early spring and is distinguished by complex inflorescences-earrings (the latter are used in medicine).

   

2. Aspen and poplar. These are the only representatives of the willow family that do not have nectaries. All others are pollinated by insects.

   

3. Monoecious plant with same-sex flowers. Flowering of catkins is observed even before the foliage appears.

   

4. All members of the family are pollinated by wind. The most common of them include walnut, gray and black walnut, as well as hazel.

   

5. Alder. This tree also blooms before the leaves appear. But, characteristically, some types of alder bloom in autumn, when the leaves fall. Earrings in this case are single-sex.

   

6. Beech family. Monoecious wind-pollinated crops, the most famous of which is oak. By the way, in nature there are over 500 varieties of oak, and all of them begin to bloom simultaneously with the appearance of leaves. The family also includes edible chestnut (not to be confused with horse chestnut) and, in fact, the beech itself.

   

7. In this monoecious culture, the catkins also begin to bloom at the same time as the foliage appears.

   

8. Representative of the cereal family, which includes six species, of which only one is cultivated.

   

   

9. Herbs. Wind-pollinated grasses primarily include cereals, plantain, sedge, nettle, hops and hemp.

   

Note! The list contains only the most common representatives of anemophilous plants, so it cannot be considered complete.

wind pollination process

Pollen dispersal by wind can hardly be considered a controlled process. Therefore, the probability that the grains will fall on the stigmas of their own flowers is quite high. Self-pollination, as you know, is undesirable for such plants, and therefore flowers have widely developed various fixtures that prevent this. So, most often the stigmas and anthers do not ripen at the same time. For the same reason, some wind-pollinated crops have dioecious flowers.

Most of the trees pollinated in this way bloom in early spring, that is, before the foliage blooms - this is also a device that prevents self-pollination.

This is especially pronounced in hazel and birch. And no wonder, because thick leaves would be a serious obstacle to moving pollen grains.

It is worth mentioning other devices. The stamens of most cereal plants begin to grow very quickly when the flowers open, and the growth rate can reach 1-1.5 mm / min. After a while, the length of the stamens is three to four times greater than the original, they go beyond the flower and hang down. And only after the dust particles are below, they crack. At the same time, the anther itself is slightly bent, forming a kind of bowl where the pollen is poured. As a result, the grains do not fall to the ground, but calmly wait for a gust of wind to leave the anther.

Note! In some grasses, the pedicels open up before flowering, forming an angle of up to 80° between them. As a result, the pollen is blown away by the wind. At the end of the flowering period, the flowers return to their original position.

Also, the position of the inflorescence can change in hornbeam, poplar and birch. At first, the inflorescences “look” up, but before opening the anthers, the earring stem extends, and they (the inflorescences) hang down. Flowers move away from each other and at the same time become accessible to the wind. Pollen grains fall on the scales of the lower flowers, from where they are blown away.

Some anemophilous plants (by analogy with entomophilous ones) have "explosive" flowers. So, in one of the varieties of nettle, the stamens during the ripening period are so tense that, after opening, they sharply straighten and get rid of the grains of bursting anthers. At such moments, dense clouds of pollen are observed above the flowers.

We also note that the pollen of wind-pollinated crops may not always crumble, but only if the weather is favorable. The street should be relatively dry, the wind should be weak or medium. Often, morning hours are most suitable for pollination.

Conclusion

As a result, I would like to give a few words to the planting of wind-pollinated crops. We will immediately make a reservation that it is not necessary to mix such plants, since each species has its own adaptations and principles. All grasses, as noted above, are anepophilic and all of them bloom only after foliage appears on the trees. But cereals are not "loners", they grow in groups - and large ones - in steppes, meadows, etc. (in other words, in open space).

But with bushes and trees, things are different: these crops, growing in forests, are located at a certain distance from each other.

Video - Wind Cross Pollination

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Attention! The slide preview is for informational purposes only and may not represent the full extent of the presentation. If you are interested in this work, please download the full version.

Lesson objectives: to introduce students to the various methods of pollination in flowering plants, to consider adaptations to various methods of pollination that arose during evolution .

Lesson objectives:

Educational: show the importance of pollination in plant life.

Developing: to form the ability to highlight the main thing, compare, systematize the features of insect-pollinated and wind-pollinated plants, continue the formation of the ability to work with a textbook.

Educational: promote the ethical education of children, instill a love of nature.

Lesson type: combined.

Teaching methods: reproductive, partially exploratory, work in pairs.

Equipment: tables "The structure of a flower", "Pollination of flowers by insects", "Wind-pollinated plants", "Artificial pollination of corn", envelopes with a task, a computer, a projector, an educational disk "Biology -6", a herbarium of self-pollinated and cross-pollinated plants, a presentation for the lesson , workbook No. 1.

During the classes

1. Organizational part of the lesson.
2. Updating students' knowledge.
3. Exploring a new topic.
4. Consolidation of new material.
5. Summing up the lesson. Putting marks.
6. Homework.

1. Organizational part of the lesson.

2. Actualization of students' knowledge. Checking homework.

All the life the flowers don't leave us
Beautiful heirs of nature.
They come to us at dawn,
At sunset, they carefully leave.

A) Frontal conversation on the questions:

What plants are called flowering plants?

What is a flower? What are the main parts of a flower?

What is the structure of the pistil?

What develops from the ovary of the pistil?

What is the structure of a stamen?

What is in the anther of a stamen?

What is an inflorescence

b) Work in pairs. Solving a crossword puzzle on the topic covered

(children receive crossword puzzles and start solving it).

C) Summarizing the answers (slide number 1-transition to a new topic)

3. Learning a new topic. (

slide number 2)

A) goal setting

B) problematic issue

Why does the plant bloom? To please us humans?

Why are there many different insects on plants during this period?

Teacher: (slide number 3) Summarizes the students' answers and together define "bloom"

- What is pollination?

(Suggested student answers) (slide number 4)

The value of pollination (slide number 5)

Pollination types: (slide number 6)

A) self-pollination B) cross-pollination. Self-pollination.

Slide number 7. Self-pollination. Give a brief description of self-pollination. Why do you think plants need to self-pollinate?

(Suggested student responses)

What adaptations do plants have for self-pollination?

(Suggested student responses)

- often occurs in unopened flowers, that is, in a bud;

- the stamens are longer than the pistils and the pollen from them, under the influence of gravity, itself crumbles onto the pistils;

Then together we formulate a conclusion and pay attention to (slide No. 8).

Plant adaptations for self-pollination.

Slide number 9. Examples of plants in which self-pollination is observed.

Slide number 10. Cross pollination (definition). Give a brief description of cross-pollination.

Complete task #1 in workbook to paragraph 24.

Cross-pollination can be of several types.

Slides number 11-12. Cross-pollination by insects.

Guys, what do you think, what adaptations do plants have for pollination by insects? (intended student responses).

Then we formulate a conclusion together.

Slides No. 13-14. Adaptations of plants to pollination by insects.

Slide number 15. Pollination of plants by wind.

Guys, what do you think, what adaptations do plants have for wind pollination?

Slide number 16. Adaptations of plants to wind pollination.

Slide number 17. Examples of plants pollinated by the wind

(Birch, hazel, oak, alder, aspen, rye, corn, wheatgrass)

To consolidate the material, complete task No. 2 in the workbook.

Then we perform the laboratory work "Consideration of insect-pollinated and wind-pollinated plants" (Instruction card on pages 90-91)

(Students work with herbarium material, then formulate a conclusion)

Questions for students:

- How can you find out from the structure of a flower how a plant is pollinated, by wind or insects?

- What signs of adaptability appeared in the process of evolution in wind-pollinated and insect-pollinated plants?

(Suggested student responses). Then we formulate a conclusion together.

There are other ways to pollinate plants.

Slide number 17. Other ways of pollinating plants.

Slide number 18. Pollination with water.

Slide number 19. Kopyten. Ants are pollinators.

Slide number 20. Hummingbird.

Slide number 21. Baobab.

Slide number 22. Animal Couscous in Australia.

Teacher. In addition to natural pollination occurring in nature, artificial pollination is also possible. Artificial pollination is pollination carried out by humans in order to breed new varieties and increase plant yields. (student's story about methods of artificial pollination using a table

"Artificial pollination of corn"

4. Consolidation of new material

A) independent work(fill in the table). If the named feature is characteristic for this group of plants, a "+" sign is put, if not, "-"

signs	insect pollinated plants	wind pollinated plants
1.Large bright flowers
2. Small bright flowers collected in inflorescences
3. Presence of nectar
4. Small inconspicuous flowers, often collected in inflorescences
5. The presence of aroma
6. Pollen is small, dry, light, large amount.
7.Large sticky rough pollen
8. Grow in large clusters, forming thickets
9. Plants bloom in spring before the leaves open.
Flowers lack nectar

B) Find biological errors. Now let's check how much you understood the topic studied. Our school received 2 letters from residents of the Flower City. You probably all remember one of the residents of the city - Dunno, who was invented by the writer Nosov. Dunno seriously decided to take up botany, but, as usual, got everything mixed up. Help him.

1 competition "Compositions of Dunno"

Your task is to find biological errors in Dunno's poems.

1. There was a birch in the field
And her bee pollinated
(Birch is pollinated by the wind)
2. As in our garden
Blooming sweet peas
Flies, bees will fly,
Let's wait for the harvest
(Pea is a self-pollinating plant)

2 competition "Why". The second letter from Znayka. He also asks you to answer questions that differ from Znayka's questions in their seriousness and correctness.

1. Why do plants that bloom in the evening and at night more often have corollas of white and yellow color?
2. Why can calm weather during flowering cause a decrease in rye yields, but such weather does not affect the wheat yield?
3. Why in the spring, few people notice the flowering of birch.
4. Why did one of the two flowers of an apple tree form a fruit, while the other did not? Why did it happen?

Introduction.

Spring, especially April and the first half of May, is a very suitable time for ecological studies of plants. During this period, transitional from winter to summer, you can see a wide variety of natural phenomena, moreover, in central Russia, where we live, all processes are so fast that many of them can be traced in development, and sometimes even from the beginning. to end.
In spring, the ecological diversity of communities is extremely fully revealed, and some groups of organisms can be observed only in spring, for example, ephemeroids. And the conditions for research are favorable - at this time, as a rule, the weather is dry and warm.
Scientists distinguish several groups of plants blooming in spring: (Biology at school No. 2, 1998 // Primroses: a research project for schoolchildren, p. 67)
1) Early spring plants, developing and flowering in early spring, soon after the snow melts or even simultaneously, long before the leaves bloom in trees and shrubs and most herbaceous plants, calendar - April and the first half of May (corydalis, goose onion, anemone, violets).
2) spring plants, giving flowers after the first group or at the time of their flowering, calendar - in the second half of May (sour, raven eye, Peter's cross).
3) Late-spring plants blooming already in the beginning and second decade of June (fragrant woodruff, double-leaved mullet, wild rose, honeysuckle, etc.) This paper presents the results of studying the first group of plants, i.e. early spring plants.

Goal of the work: study of early spring flowering plants and their ecological groups.

Tasks:

• identify species of early spring plants;
• determine the frequency of their occurrence;
• make a herbarium;
• give biological characteristic species;
• establish ecological groups of early spring flowering plants;
• identify plant species in need of protection;
• formulate recommendations for rational use and protection of early spring plants.

The study was conducted 2 kilometers east of the village of Kazachy, Prokhorovsky district, from April 1 to May 10.

Research methodology

The study of the territory for the detection of early spring flowering plants was carried out by the route method. The routes covered the eastern territory of the vicinity of the village and all the main habitats: forest edges, glades, meadows, ditches along the roads, wastelands. The research was carried out in the period from April 1 to May 10, access to the route was carried out twice a week.
In the process of work on the route, the frequency of occurrence of these plants was recorded, the records were kept by eye, all plant species were divided into three groups: they are common and abundant, they are moderately frequent and rare.
Also, along the route, the habitats of plants and their need for certain environmental factors were noted, for the subsequent determination of ecological groups.
Herbarium materials were collected. Herbaceous plants were collected without underground organs (except for those where it was necessary to identify the species, such as Corydalis).
A plan of the surveyed area was drawn up, it shows the habitats of the species. Each species is given a brief description of photographs taken. The results are presented in the form of herbariums and tables.

general characteristics early spring plants.

Plants need sunlight to function properly. It is in the light that the processes of photosynthesis take place, when from inorganic substances organic ones are formed, which are then used by plants for their development.
In the April forest, the trees and shrubs are not yet covered with foliage, nothing prevents the sunlight from penetrating to the very ground. This is the main reason that many plant species in the process of evolution have “chosen” for their development early spring.
In addition, the ground after the snow melts is saturated with moisture, which is also necessary condition for the normal development of the plant organism.
Already from the moment of snow melting in the forest community, in many plants one can observe already developed stems with young, slightly green leaves, as well as formed buds. This group of plants has another feature of development. In the second half of summer and autumn, early spring flowering plants experience a significant increase in renewal buds with the isolation of inflorescences laid in them. The growth rate of points increases as autumn approaches. During the winter months, both pollen grains and embryo sacs are formed in the flowers of early spring plants. Without exposure to low temperatures for a certain period, early spring plants do not develop. Even in those cases when the soil in the forest really freezes, the young parts of the plants do not freeze. This phenomenon is explained by the fact that the freezing temperature of cell sap in overwintering plants is much lower than 0C. In hibernating organs, starch is replaced by sugar. The sugar concentration is high, the freezing point is lower.
All early spring flowering plants are perennials, many store spare nutrients in tubers, bulbs, rhizomes, stem core for fast and early flowering.
The “transparency” of a leaf-free forest plant is also used for pollination. In a bare spring forest, nothing prevents the wind from transferring pollen from male flowers (collected in “dusty” catkins) to female flowers, consisting of only small sticky pistils. This is very typical for trees and shrubs that bloom in spring. Another interesting phenomenon for the spring forest is wind-pollinated grasses, for example, hairy sorrel. Her flowers are small, inconspicuous, but the absence of other herbs and the mass accumulation of these plants allows her to pollinate. The pollen is light and very dry.
Low-growing insect pollinated plants attract the first insects bright flowers. Who will notice their flowers in the dusk of a summer forest? And in the spring, when the lower tiers of the forest are well lit, yellow (anemone), blue (violets), purple (tenacious, Corydalis) and pink flowers are best seen here.
But the small plants allocated to the group of "ephemeroids" use all the favorable spring factors most fully.
Ephemeroids- This is a very special group of plants with peculiar habitats. In short, these are those plants which, having subterranean organs, go through their annual growing season as quickly as the ephemera. The word "ephemeral" is associated with something beautiful, but fleeting, short-lived. In our forests, their "hurried" life is associated with a sharp change in the light flux. If at the beginning of May the illumination and temperature in the forest is comparable to the illumination and temperature in open areas, then at the height of summer in the forest it is both darker and colder. This prevents not only the normal development of plants, but also the normal life of pollinators. (Biology at school. No. 1 1994 // Spring phenomena in plant life, p. 63)
An example of them could be different kinds corydalis, goose onions, anemones. They are born immediately after the snow melts. It is quite cool at this time of the year, but the ephemeroids develop very quickly nonetheless. After a week or two, they already bloom, and after another two or three weeks, their fruits with seeds already ripen. At the same time, the plants themselves turn yellow, lie down on the ground, and then their aerial part dries up.
All ephemeroids are perennials. After the aerial part dries up, they do not die. Their living underground organs are preserved in the soil: tubers, bulbs, rhizomes. These organs are receptacles for spare nutrients. It is precisely because of this building material so quickly ephemeroids develop in the spring. With such a short growing season, and even with an unfavorable spring temperature regime one cannot accumulate many nutrients necessary for the development of tall and powerful stems and large leaves. Therefore, all our ephemeroids have small size. (Petrov V.V. Vegetable world our motherland. M: Enlightenment, 1991, p.63).
There is another problem with perennial early spring flowering plants - seed dispersal. By the time their seeds ripened, trees and shrubs were already covered with leaves, summer grasses had risen. There is practically no wind in the forest, so the distribution of seeds with its help is not effective, and even animal hair cannot be reached. They also do not have time for the ripening of juicy berries that forest animals would eat. But who is always in abundance in the forest is ants. On the fruits or seeds of these plants, special fleshy appendages are formed, rich in oil - elaiosomes ( from the Greek elaion - oil, soma - body), which attract ants. Plants that spread their seeds with the help of ants are called myrmecochores. Myrmecochores include all our ephemeroids, as well as approximately 46% of all forest herbaceous plants. (Biology at school. No. 2, 1998, p. 70).

Research results

During the research work 17 species of early spring flowering plants were identified:
1. Warty birch.
2. Veronica oak.
3. Anemone is rancid.
4. Goose bow.
5. Pedunculate oak.
6. Tenacious creeping.
7. Starry oak.
8. Ash-leaved maple.
9. May lily of the valley.
10. Common hazel.
11. Mother and stepmother.
12. Hairy hairy.
13 Spring Companion.
14. Trembling poplar (aspen).
15. Dog violet.
16. Corydalis dense.
17. Common bird cherry.

Having studied the characteristics of these plants, I divided them into ecological groups 1) in relation to light; 2) in relation to moisture;
3) according to the method of pollination; 4) ephemeroids; 5) according to life forms.

By in relation to light It is customary to distinguish three main groups of plants: 1. heliophytes- (from the Greek "helios" - the sun, "phyton" - a plant) plants of open spaces, well-lit habitats; 2. facultative heliophytes– species that can live at full sunlight, but they also tolerate some darkening;

3. sciophytes- (from the Greek "skia" - shadow) species that do not grow in open spaces. (Life of plants, vol. 1 M: Enlightenment 1997, p. 65). These three categories of plants are, of course, not sharply demarcated. Not always the growth of plants in illuminated places (or shaded) indicates their actual need for light.

By in relation to moisture.
Plants are classified according to their ability to retain moisture.

1. Poikilohydride these plants easily absorb and easily lose water, tolerate prolonged dehydration. As a rule, these are plants with poorly developed tissues (bryophytes, ferns, algae). 2. Homoyohydrides- plants capable of maintaining a constant water content in tissues themselves, among them there are different ecological groups (Plant Life, vol. 1, p. 76):
- hydatophytes– aquatic plants wholly or almost wholly submerged in water;
- hydrophytes- water-terrestrial, attached to the soil near water bodies and on abundantly moistened soil far from water bodies;
- hygrophytes- plants living on abundantly moist soils and at high humidity;
-mesophytes- plants that live with sufficient moisture;
- xerophytes- plants that can extract moisture when it is lacking, limit the evaporation of water or store water.
Ecological groups of early spring flowering plants in relation to light and moisture.

The name of the species.	In relation to the world.	In relation to hydration.
Warty birch	heliophyte	mesophyte
Veronica oak	heliophyte	mesophyte
Anemone buttercup	sciophyte	mesophyte
goose bow	heliophyte	mesophyte
Pedunculate oak	heliophyte	mesophyte
tenacious creeping	heliophyte	mesophyte
chickweed oakwood	heliophyte	mesophyte
Ash maple	heliophyte	mesophyte
May lily of the valley	Facultative heliophyte	mesophyte
common hazel	Facultative heliophyte	mesophyte
Coltsfoot	heliophyte	mesophyte
Ojika hairy	Facultative heliophyte	mesophyte
Sochevichnik spring	sciophyte	mesophyte
Poplar trembling	heliophyte	mesophyte
dog violet	Facultative heliophyte	mesophyte
corydalis dense	heliophyte	mesophyte
Common bird cherry	heliophyte	mesophyte

Analyzing the collected data presented in the table, all the early spring flowering plants that I found - mesophytes, and all these plants are heliophytes, with the exception of spring sochechnik, buttercup anemone - they sciophytes.

By pollination method
All early flowering plants are cross-pollinated by wind and insects. It is necessary to bloom early for successful pollination, especially for wind-pollinated ones, when there is still no foliage on trees and shrubs. Male inflorescences can be many times larger than female single or clustered flowers in order to produce as much fine, dry and very light pollen as possible. They say about such flowering - the plant "dusts".
Ephemeroids

Plants that quickly go through their annual growing season.

Ecological groups of early spring flowering plants according to the method of pollination and the duration of the growing season.

The name of the species.	Pollination method.	By the length of the growing season.
Warty birch	Wind pollinated.
Veronica oak	Insect pollinated.
Anemone buttercup	Insect pollinated.	Ephemeroid
goose bow	Insect pollinated.	Ephemeroid
Pedunculate oak	Wind pollinated.
tenacious creeping	Insect pollinated.
chickweed oakwood	Insect pollinated.
Ash maple	Wind pollinated.
May lily of the valley	Insect pollinated.
common hazel	Wind pollinated.
Coltsfoot	Insect pollinated.
Ojika hairy	Wind pollinated.
Sochevichnik spring	Insect pollinated.
Poplar trembling	Wind pollinated.
dog violet	Insect pollinated.
corydalis dense	Insect pollinated.	Ephemeroid
Common bird cherry	Insect pollinated.

By life forms.
The term "life forms" was introduced in the 80s of the 19th century by the famous Danish botanist E. Warming, one of the founders of plant ecology. Warming understood the life form as “a form in which the vegetative body of a plant (individual) is in harmony with the external environment throughout its entire life, from the cradle to the coffin, from seed to death” (Life of Plants, vol. 1 p. 88) . Speaking about the harmony of the plant with environment, is meant historically developed in the course of evolution the adaptability of plants to a complex of external factors that dominate in the area of ​​​​its distribution.
The most popular among botanists is the classification of life forms proposed by the Danish botanist K. Rawinker (Life of Plants, vol. 1 p. 91). He singled out one sign - the location of renewal points from the surface of the earth, from which new shoots will develop:
1.Fanerophytes(Greek "Phaneros" - open, obvious) - in this type of plants, the points of renewal overwinter openly, quite high. They are protected by special bud scales. These are all trees and shrubs.
2. geophytes(Greek "geos" - earth) - renewal buds are stored in the earth. The above-ground part dies off for the winter. New shoots develop from buds located on bulbs, tubers or rhizomes wintering in the soil.
3. Hemicryptophytes(Greek "hemi" - semi-, and "crypto" - hidden) are herbaceous plants whose renewal buds are above the soil level, often under the protection of fallen leaves and other plant debris.

4. X amephites(renewal points at a height of 20-30 cm above the ground)

5. T erophytes(renewal buds in seeds). But I did not find such early spring flowering plants.

During the work, I carried out an eye count of the frequency of occurrence of species, which I displayed in the table.

plant species	life form	Frequency of occurrence	Habitat
Warty birch	Fanerofit	Often	surrounding forests
Veronica oak	geophyte	Often	Wastelands, forest edges.
Anemone buttercup	geophyte	Rarely	Thickets of shrubs.
goose bow	geophyte	Often	Arable lands, forest edges, slopes, ditches.
Pedunculate oak	Fanerofit	Moderately often	surrounding forests.
tenacious creeping	Hemicryptophyte	moderately often	surrounding forests.
chickweed oakwood	geophyte	Often	Surrounding forests, edges.
Ash maple	Fanerofit	Rarely	Edges of the forest, settlement.
May lily of the valley	geophyte	Often	Surrounding forests, edges.
common hazel	Fanerofit	Often	Edges of the forest.
Coltsfoot	geophyte	Often	Ditches along roads, fields.
Ojika hairy	geophyte	Often	surrounding forests.
Sochevichnik spring	geophyte	Often	surrounding forests.
Poplar trembling	Fanerofit	Often	Edges of the forest.
dog violet	geophyte	moderately often	Surrounding forests, edges.
corydalis dense	geophyte	Rarely	Edges of the forest.
Common bird cherry	Fanerofit	moderately often	Edges of the forest.

Conclusions.

Based on the study:

1. 17 species of early spring flowering plants were found.
2. Most of these plants are found moderately often and often in the vicinity of the village.
3.Basic environmental groups these plants are:
- in relation to the light - heliophytes;
- in relation to moisture - mesophytes;
- according to the method of pollination - wind-pollinated and insect-pollinated,
- according to life forms - phanerophytes, geophytes, hemicryptophytes.
4. The presence of ephemeroids was revealed.
5. Among the early spring plants, no protected ones have been identified.

Conclusion.

In the course of my research work, I did not identify rare and protected species among early spring flowering plants. But, nevertheless, they need protection. Appearing first after a long winter, they attract increased attention, which leads to a massive collection, especially those species that have beautiful flowers(corydalis, anemones, sochechniks). Explanatory work can save them from thoughtless collection, and not only among children, but also among adults. Many of the species presented in this work are medicinal. It is very important that these plants do not fall into the lists of endangered ones.
I intend to continue my work, because it seems to me that I have not met all the plants of this group yet.
The results of my work can be used by students of the 6th grade when studying the vegetation of our region in biology lessons.

List of used literature.
1. Plant life. Edited by Fedorov A.A. M: Enlightenment, 1974.
2. Petrov V.V. The flora of our Motherland. M: Enlightenment, 1991.
3. Tikhomirov V.N. Key to higher plants of the Yaroslavl region. Yaroslavl, Upper - Volga book publishing house, 1986.
4. Biology at school No. 1. 1994 // Shipunov A.B. Spring phenomena in plant life.
5. Biology at school number 2. 1998 //Klepikov M.A. Primroses.
6. Biology at school number 2. 2002 //Antsiferov A.V. Early spring field trip with sixth graders.

Spring is the time for the awakening of nature. According to the calendar, spring begins on March 1. In nature, spring comes into its own with the beginning of sap flow in trees, in the south - earlier, and in the north - later than March 1.

The spring movement of juices near trees and shrubs is the first sign of spring. It occurs after the soil thaws and water from the roots begins to flow into all organs of the plant. At this time, there are still no leaves and water, accumulating in the cells of plant stems, dissolves the organic nutrients stored in them. These solutions move to swollen and blooming buds.

Earlier than in other plants, already in early March, the spring sap flow begins in Norway maple. A little later, you can observe the movement of sap near the birch.

The second sign of spring is the flowering of wind-pollinated trees and shrubs.

The firstborn of spring flowering in the middle zone of the European part of the USSR is gray alder. Its flowers are inconspicuous, but the blossoming catkins of staminate flowers are clearly visible in early spring. One has only to touch an alder branch with hanging catkins, as the wind picks up a whole cloud of yellow pollen.

Pistillate alder flowers are collected in small grayish-green inflorescences. Next to them, dry, blackened cones of last year's inflorescences are usually clearly visible.

By these black cones and catkins that sway and dust in the wind, alder is easy to distinguish from other trees in the spring.

Almost simultaneously with the alder, the hazel, which you met in the fall, blooms.

Early flowering of alder, hazel and other wind-pollinated plants is a good adaptation to life in the forest. In spring, the forest is transparent. Bare leafless branches do not impede pollination. Pollen, picked up by the wind, is freely transferred from one plant to another.

Flowering coltsfoot is also a sign of the coming spring. This perennial herbaceous plant grows in open, sunlit places, on railway embankments, river banks, steep slopes and cliffs. As soon as the snow melts, its leafless scaly stems already appear - flower stalks with bright yellow inflorescences, similar to dandelion inflorescences. The large leaves of the coltsfoot grow only after its fluffy fruitlets have ripened and scattered. The coltsfoot received its unusual name for the originality of the leaves. Their underside is covered with white, soft, like felt, hairs. Gentle, warm to the touch, they involuntarily make you remember the tender mother's hands. And the upper side of the leaves, smooth and cold, resembles an unfriendly stepmother.

Columbus blooms in early spring, before the leaves open, perhaps because its thick, long underground stems have accumulated reserves of nutrients deposited in the summer of last year. Feeding on these reserves, flower shoots grow and fruits are formed.

The third sign of spring is the flowering of perennial herbaceous plants of the deciduous forest. In the districts middle lane they also bloom in early spring, almost simultaneously with the coltsfoot. The first to bloom in the forest is the liverwort with azure or purple flowers and lungwort, then anemone, corydalis, chistyak and some other herbaceous plants. All of them are photophilous and have adapted to flowering under the forest canopy, when there are no leaves on the trees and shrubs.

Dig around some of the forest's early-flowering herbaceous plants and you'll understand why they've grown and bloomed so quickly. It turns out that each early-flowering plant has its own “pantry” with a supply of nutrients. In lungwort, they are stored in a thick underground stem. In the Corydalis - in a single small tuber, and in the Chistyak - in root tubers, similar to small oblong nodules.

The most interesting thing in the life of some early-flowering herbaceous plants of the forest is their growth under snow. Plants such as blueberry or snowdrop grow even in winter under the snow. In spring, many of them emerge from under the snow with green leaves and buds, and often bloom even before the snow melts. That is why these plants are called snowdrops.

Trees and shrubs pollinated by insects bloom much later, when their leaves have already blossomed. If you year after year

to observe the course of spring, you will be able to establish the sequence of spring development of plants in your area and draw up a spring calendar. So, usually 8 days after the flowering of the coltsfoot, the lungwort begins to bloom, after 21 days - the dandelion and willow willow. The pear blossoms on the 29th day, the yellow acacia on the 30th, and the linden on the 75th day after the start of flowering of the coltsfoot. Deviations from these terms almost never happen.

Watching plants bloom and buds open, you will see that every year the spring phenomena come in strict order. Lungwort, for example, always blooms later than coltsfoot, but before dandelion.

Observations of spring phenomena in plant life help to establish best timing agricultural work and prepare for them in a timely manner.

For example, it is known that in the regions of the middle zone best harvest cucumbers are obtained by sowing their seeds during the flowering of lilac and yellow acacia, and the best crop of turnips and beets is obtained by sowing them during the flowering of aspen. Knowing how many days after the coltsfoot blooms lilacs bloom, it is easy to set the time for sowing cucumbers and prepare for it.

But it is not enough to confine oneself to observing the life of plants and the timing of their flowering. It is necessary not only to love nature, but also to protect and increase its wealth. Each student must protect the perennial plants of his area. Find out what trees and shrubs of rare species grow in the vicinity of the school. Pay attention to giant trees, to durable and fast-growing species with light and durable wood. Protect plants from breakage and other damage, collect seeds of rare plants, grow valuable trees and shrubs from seeds.

"Know, protect and multiply natural wealth" - let these words become the motto of every pioneer and schoolchild.

In 1968, the All-Union Conference on Plant Protection was held in Leningrad in our country.

For science-based research, Owen Nilsson of the Swedish Plant Research Center Umeå has revealed why plants bloom with vesta.

Every morning as the sun sets over the horizon - regardless of the time of year - the clock starts ticking inside the trees.

• After a certain amount of time, plant cells begin to produce high levels molecules known as the FT protein.
• This protein is responsible for initiating the processes that help the plant grow.
• But the FT protein has a curious property: in the absence of sunlight it suspends its selection. Therefore, when the sun goes down, the protein becomes useless for the plant.

Scientists' opinion

Scientists believe this feature is the key to the seasonality of some flowering plants, including most trees that bloom in the spring.

If a plant is genetically programmed to produce a large amount of FT protein starting, say, 13 hours after dawn, the molecule will be abundant during the last few hours of daylight on the longer days of summer. And these few hours are enough to start the critical growth processes.

As autumn progresses and the days shorten, the number of hours will vary by species and even by individual plant. The trees take this as a signal to drop their leaves and stop generating new buds.

When winter sets in, day length and temperature reach their annual minimum. At this stage, the plant goes through vernalization, a period of dormancy that is of great importance for the protection of trees.

In the spring, it can be assumed that the FT protein process is activated: the days become longer, the FT protein is produced during the daytime, and the plant begins its growth and flowering process.

If it warms up too early during the winter, the tree may take this as a sign that spring has arrived. However, when temperatures drop, as it always does at the end of winter, the tree's seeds do not germinate or grow, hindering the tree's reproductive process.