The flowers of which plant are not pollinated by the wind. Why do wind-pollinated trees and shrubs bloom early in spring? Features of anemophilous plants
Wind-pollinated plants are plants that are pollinated by the wind, however, under various circumstances, they can also be pollinated by insects. Wind-pollinated plants have very small and numerous flowers. Such plants produce a lot of pollen: one plant can produce millions of pollen grains. In many wind-pollinated plants (hazel, aspen, alder, mulberry), flowers appear even before the leaves bloom.
Wind-pollinated plants. Plants whose flowers are pollinated by the wind are called wind-pollinated. Usually their inconspicuous flowers are collected in compact inflorescences, for example, in a complex spike, or in panicles. They produce a huge amount of small, light pollen. Wind-pollinated plants most often grow in large groups. Among them there are grasses (timothy grass, bluegrass, sedge), and shrubs and trees (hazel, alder, oak, poplar, birch). Moreover, these trees and shrubs bloom simultaneously with the leaves blooming (or even earlier).
In wind-pollinated plants, the stamens usually have a long filament and carry the anther outside the flower. The stigmas of the pistils are also long, “shaggy” - to catch dust particles flying in the air. These plants also have some adaptations to ensure that pollen is not wasted, but preferentially lands on the stigmas of flowers of its own species. Many of them bloom by the hour: some bloom early in the morning, others in the afternoon.
Wind-pollinated plants have the following characteristics:
– inconspicuous small flowers, often collected in inflorescences, but small and inconspicuous;
– feathery stigmas and anthers on long hanging threads;
– very fine, light, dry pollen.
Examples of wind-pollinated plants: poplar, alder, oak, birch, hazel, rye, corn. Wind-pollinated trees typically bloom in the spring, before leaves emerge that would interfere with the transfer of pollen.
Wind-pollinated plants include oaks and beeches, alder and birch, poplars and plane trees, walnut and hazel. In addition to trees, many herbs that usually live in large communities are pollinated by the wind: cereals, rushes, sedges, hemp, hops, nettles and plantains. This list contains only examples; it does not at all claim to be a complete list of names of wind-pollinated plants.
The first striking feature of wind-pollinated flowers is the lack of bright color and aroma, and the absence of nectar. On the contrary, pollen grains develop in great abundance. Moreover, they are extremely small: in wind-pollinated plants, an individual grain of dust has a mass of 0.000001 mg. For comparison, we can recall that a bee-pollinated pumpkin has a dust grain that is a thousand times heavier: its mass is 0.001 mg. One inflorescence of rye is capable of producing 4 million 200 thousand pollen grains, and the inflorescence of horse chestnut is even ten times more - 42 million. Feature The advantage of pollen grains of wind-pollinated flowers is that they are completely devoid of adhesive substances and in most cases have a smooth surface.
Despite the fact that wind-pollinated flowers lack nectar, they are often visited by insects that feed on pollen. However, these insects play almost no role as pollen carriers.
The spread of pollen that a plant “throws to the wind” is, of course, an uncontrollable process. And the likelihood that pollen grains will fall on the stigma of your own flower is very high. But, as we know, self-pollination is undesirable for a plant. Therefore, wind-pollinated flowers have widely developed adaptations that prevent it. Particularly common is the non-simultaneous maturation of anthers and stigma. For probably the same reason, many wind-pollinated plants have dioecious, and sometimes bidominous, flowers.
Most wind pollinated woody plants blooms early spring, even before the leaves bloom. This is especially clearly visible in birch and hazel trees. After all, it is clear that dense summer foliage would be a very difficult obstacle to overcome for pollen flying in the wind.
Some other adaptations to wind pollination can also be mentioned. In many cereals, the stamens, when the flower opens, begin to grow unusually quickly, lengthening by 1–1.5 mm every minute. In a short time, their length is 3–4 times greater than the original, they grow beyond the flower and hang down. And only when the anthers are at the bottom, they begin to crack, and the anther here bends somewhat and forms a kind of tray or bowl into which the pollen is poured. In this way, she does not fall down onto the ground, but waits for the next gust of wind to fly on its wings.
It is interesting that the pedicels in the spikelets of some cereals seem to spread out at the beginning of flowering, forming an angle of 45–80° between themselves. This also helps the pollen to be blown away by the wind. As soon as the flowering ends, the pollinated flowers return to their place.
During flowering, the position of the entire inflorescence also changes in birch, poplar, and hornbeam. At first, the inflorescences are directed upward. But before the anthers begin to burst, the stem of the catkin extends and the inflorescence hangs down. Each flower then becomes separated from the other and accessible to the wind. Pollen falls from the anthers down onto the scales of the lower flower and is blown away by the wind from here.
Wind-pollinated plants also have an “explosive” type of flower, similar to that of insect-pollinated plants. Thus, the stamens of a flower of one of the nettle species ripening in the bud are so tense that when it opens, they sharply straighten and scatter pollen from the bursting anthers. At this moment, a thick cloud of pollen can be seen above the flower.
The pollen of wind-pollinated flowers is not scattered by them at any time of the day or night, but only in favorable weather, usually relatively dry, with a weak or medium wind. Most often, the morning hours are most suitable for pollination.
Comparison of insect-pollinated and wind-pollinated plants
|
Signs of a flower |
Insect-pollinated plants |
Wind-pollinated plants |
| Dull or absent | ||
|
2. Location of stamens |
Inside a flower |
Open, anthers on long threads |
|
3. Stigmas of pistils |
Small |
Large, often feathery |
| Not very much, sticky, large | A lot, dry, small | |
|
Many have |
||
|
Many have |
Spring is the time for nature to awaken. According to the calendar, spring begins on March 1st. In nature, spring comes into its own with the beginning of sap flow in the trees, in the south - earlier, and in the north - later on March 1.
The spring movement of sap in 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 no leaves yet and water, accumulating in the cells of plant stems, dissolves the organic nutrients stored in them. These solutions move to the swollen and blossoming buds.
Earlier than other plants, already in early March, spring sap flow begins in Norway maple. A little later, you can observe the movement of sap in the birch tree.
The second sign of spring is the flowering of wind-pollinated trees and shrubs.
Firstborn spring bloom V middle lane European part of the USSR - gray alder. Its flowers are inconspicuous, but the blooming earrings of staminate flowers are clearly visible in early spring. As soon as you touch an alder branch with dangling earrings, the wind will pick 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 by the earrings that sway and gather dust in the wind, alder is easy to distinguish from other trees in the spring.
Almost simultaneously with the alder, the hazel tree, which you met back 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.
The flowering of 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 appear - flower stalks with bright yellow inflorescences, similar to the inflorescences of dandelions. The large leaves of coltsfoot grow only after its fluffy fruits have matured and scattered. Yours unusual name coltsfoot received for the originality of the leaves. Their underside is covered with white, soft, felt-like hairs. Gentle and 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 inhospitable stepmother.
Coltsfoot blooms in early spring, before the leaves bloom, possibly because reserves have accumulated in its thick, long underground stems nutrients, postponed last summer. Feeding on these reserves, flower shoots grow and fruits are formed.
The third sign of spring is the flowering of perennial herbaceous plants in the deciduous forest. In the middle zone they also bloom in early spring, almost simultaneously with coltsfoot. The first to bloom in the forest are liverworts and azure or purple flowers and lungwort, then anemone, corydalis, chistyak and some others - herbaceous plants. All of them are photophilous and have adapted to flowering under the forest canopy, when there is no foliage on trees and shrubs.
Dig up the soil around some of the forest's early-blooming herbaceous plants and you'll understand why they grew 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 chistyata - 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 scilla or snowdrop grow under the snow in winter. In spring, many of them emerge from under the snow with green leaves and buds, and often bloom even before the snow melts. That's why these plants are called snowdrops.
Trees and shrubs pollinated by insects bloom much later, when their leaves have already blossomed. If you go from year to year
observe the progress 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, lungwort begins to bloom, and 21 days later - dandelion and willow willow. The pear blooms on the 29th day, the yellow acacia on the 30th, and the linden on the 75th day after the coltsfoot begins to flower. Deviations from these deadlines almost never happen.
Watching the flowering of plants and the blossoming of buds, you will be convinced that every year spring phenomena occur in strict order. Lungwort, for example, always blooms later than coltsfoot, but earlier than dandelion.
Observations of spring phenomena in plant life help to establish best timing carrying out agricultural work and preparing for it in a timely manner.
For example, it is known that in areas of the middle zone best harvest cucumbers are obtained by sowing their seeds during the flowering of lilac and yellow acacia, and the best harvest of turnips and beets is obtained by sowing them during the flowering of aspen. Knowing how many days after the flowering of the coltsfoot lilac blooms, it is easy to set the date for sowing cucumbers and prepare for it.
But it is not enough to limit ourselves to observing the life of plants and the timing of their flowering. We must not only love nature, but also protect it and increase its wealth. Every student must protect perennials your locality. Find out which rare trees and shrubs grow in the vicinity of the school. Pay attention to giant trees, durable and fast-growing species with light and durable wood. Protect plants from breakage and other damage, collect seeds of rare plants, grow from seeds valuable trees and shrubs.
“Know, protect and multiply natural resources"- let these words become the motto of every pioneer and schoolchild.
In 1968, an All-Union meeting on plant protection was held in our country in Leningrad.
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, cultures are divided into several large groups: wind-pollinated, pollinated by animals (mainly insects, so we will call such plants insect-pollinated) and water (hydrophily, observed infrequently, so will not be considered). In representatives of all these groups, cross-pollination occurs, i.e., 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 characteristics and differences of each group.
Plants, as we just found out, can be pollinated either by the wind or by insects.
Wind-pollinated crops, their characteristics
To begin with, the plants that belong to this group (they are also called anemophilous) can, under certain circumstances, be pollinated by insects, although this does not happen often. Such plants are distinguished by their numerous small branches, and also by the fact that they are capable of producing large amounts of pollen (each specimen produces several million pollen grains). In many crops (such as mulberry or hazel), the formation of flowers begins even before the leaves bloom.
The flowers themselves are often inconspicuous and collected in small inflorescences. A panicle, for example, has a complex spikelet. The inflorescence produces many light and small pollen grains.
Pay attention! As a rule, wind-pollinated crops 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. Temperature conditions play an important role here: when the temperature rises, insects appear and carry pollen. In addition, all insect-pollinated crops have nectaries.
The most common representative of the group is the willow. Willow flowering can be observed both before and after the formation of foliage. But early flowering has nothing to do with wind pollination - plants resort to this “technique” exclusively to fight competitors for pollinating insects.
Table. Comparative characteristics wind- and insect-pollinated crops
| Features of flowers | Anemophilous plants | Entomophilous plants |
|---|---|---|
| Nectar | Absent | |
| whisk | Absent (or, alternatively, looks plain) | Bright |
| Smell | Absent | Available from most representatives |
| Location of stamens | Open (anthers are located on large filaments) | Inside the flowers |
| Pollen | Small, dry, in large quantities | Sticky and large, in small quantities |
| Stigmas of pistils | Large | Small |
The anthers of anemophilous crops 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 devices, so to speak, thanks to which pollen is not wasted, but falls mainly on the stigmas of other representatives of its species.
Now let’s take a closer look at the characteristics of wind-pollinated crops.
Features of anemophilous plants
All representatives of this group are characterized by the following characteristics:
- inconspicuous or inconspicuous flowers (explained by the fact that they should not attract insects);
- small and dry pollen grains;
- long length of threads on which the anthers hang.
Now more details. Main feature of all wind-pollinated crops 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, have extremely small sizes: the weight of one speck of dust is on average 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. The horse chestnut inflorescence alone is capable of forming 42 million grains, while the rye inflorescence is ten times less (4 million 200 thousand). One of the peculiarities of pollen from anemophilous plants is that it, being completely devoid of adhesive substances, often also has a smooth surface.
Pay attention! Wind-pollinated crops do not have nectar, but they are often visited by insects that feed on pollen. However, such insects play only a minor role as vectors.
What plants can be pollinated by wind?
Below are representatives of wind-pollinated crops.
- Birch family. The most common representative of the family in Europe and Asia is the warty birch, which blooms in early spring and is distinguished by complex inflorescences-catkins (the latter are used in medicine).
- Aspen and poplar. These are the only representatives of the willow family that do not have nectaries. All others are pollinated by insects.
- A monoecious plant with unisexual flowers. Flowering of catkins is observed even before foliage appears.
- All members of the family are pollinated by wind. The most common of them include walnut, gray and black walnut, as well as hazelnut.
- Alder. This tree also flowers before the leaves appear. But, characteristically, some types of alder bloom in the autumn, when the leaves fall. The earrings in this case are unisexual.
- 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 at the same time as the leaves appear. The family also includes edible chestnut (not to be confused with horse chestnut) and, in fact, beech itself.
- In this monoecious crop, catkins also begin to bloom simultaneously with the appearance of foliage.
- A representative of the cereal family, which includes six species, of which only one is cultivated.
- Herbs. Wind-pollinated grasses include, first of all, cereal crops, plantain, sedge, nettle, hops and hemp.
Pay attention! The list shows only the most common representatives of anemophilous plants, and therefore cannot be considered complete.
Wind pollination process
The spread of pollen 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 is known, is undesirable for such plants, and therefore flowers have widely developed various adaptations that prevent this. Thus, 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 the described way bloom in early spring, that is, before the leaves bloom - this is also an adaptation that prevents self-pollination.
This is especially pronounced in hazel and birch. And it is not surprising, because thick leaves would be a serious obstacle to the 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 extend beyond the boundaries of the flower and hang down. And only after the dust particles reach the bottom do they crack. At the same time, the anther itself bends slightly, forming a kind of cup into which 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.
Pay attention! In some cereals, the pedicels spread out before flowering, forming an angle of up to 80° between themselves. Thanks to this, 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” upward, but before the anthers open, the stem of the catkin extends, and they themselves (the inflorescences) hang down. The flowers move away from each other and at the same time become accessible to the wind. Pollen grains fall onto the scales of the lower flowers, from where they are blown away.
Some anemophilous plants (by analogy with entomophilous plants) have “explosive” flowers. Thus, in one of the varieties of nettle, the stamens during the ripening period become so tense that after opening they sharply straighten and get rid of the grains of the burst anthers. At such moments, thick clouds of pollen are observed above the flowers.
We also note that pollen from wind-pollinated crops may not always be scattered, but only under favorable weather conditions. It should be relatively dry outside and the wind should be light to moderate. Morning hours are often best for pollination.
Conclusion
As a result, I would like to devote a few words to planting wind-pollinated crops. Let us immediately make a reservation that there is no need to mix such plants, since each species has its own adaptations and principles. All grasses, as noted above, are anepophilous 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 at some distance from each other.
Video – Cross pollination by wind
For science-based research, Aries Nilsson from the Swedish plant science center Umeå revealed why plants bloom with flowers.
Every morning, when the sun sets over the horizon - regardless of the time of year - the clock begins to tick inside the trees.
- After a certain amount of time, plant cells begin to produce high levels molecules known as FT protein.
- This protein is responsible for initiating processes that help the plant grow.
- But the FT protein has a curious property: in the absence of sunlight, it stops its release. Therefore, when the sun goes down, the protein becomes useless to the plant.
Scientists' opinion
Scientists believe this feature is key to the seasonality of some flowering plants, including most trees that bloom in the spring.
If a plant is genetically programmed to produce large amounts 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 begin critical growth processes.
As autumn progresses and the days shorten, the number of hours will vary depending on the species and even on the individual plant. Trees take this as a signal to drop their leaves and stop producing new buds.
When winter sets in, day length and temperature reach their annual minimum. At this stage, the plant goes through vernalization, a dormant period that is of great importance for the protection of the trees.
In 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 process of growth and flowering.
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 they always do in late winter, the tree's seeds do not germinate or grow, interfering with the trees' reproductive process.
Introduction.
Spring, especially April and the first half of May, is very the right time for ecological studies of plants. During this period, the transition from winter to summer, you can see a wide variety of natural phenomena Moreover, in central Russia, where we live, all processes go so quickly that many of them can be traced in development, and sometimes even from beginning to end.
In spring, the ecological diversity of communities is extremely fully revealed, and some groups of organisms are only spring time and can be observed, for example, ephemeroids. And the conditions for research are favorable - at this time, as a rule, the weather is dry and warm.
Scientists identify several groups blooming in spring plants: (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 tree and shrub species and most herbaceous plants, calendar - April and the first half of May (crested, goose onion, anemone, violets) .
2) Spring plants that produce flowers after the first group or at the time of their flowering, calendar - in the second half of May (oxalis, raven eye, Peter's cross).
3) Late spring plants, blooming already at the beginning and second decade of June (fragrant woodruff, bifolia, rosehip, honeysuckle, etc.) This paper presents the results of the study of the first group of plants, i.e. early spring plants.
Purpose of the work: study of early spring flowering plants and their ecological groups.
Tasks:
- identify types of early spring plants;
- determine the frequency of their occurrence;
- compile a herbarium;
- give biological characteristics 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 carried out 2 kilometers east of the village of Kazachye, Prokhorovsky district, from April 1 to May 10.
Research methodology
The study of the territory to detect early spring flowering plants was carried out using the route method. The routes covered eastern territory the surrounding area of the village and all the main habitats: forest edges, clearings, meadows, ditches along roads, wastelands. The research was carried out from April 1 to May 10, the route was taken twice a week.
In the process of working along the route, the frequency of occurrence of these plants was recorded, the records were carried out by eye, all types of plants were divided into three groups: found often and abundantly, found moderately often and found rarely.
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 this was necessary for species identification, for example, corydalis).
A plan of the surveyed territory was drawn up, showing the habitats of the species. Each species is given brief description, photographs were taken. The results are presented in the form of herbariums and tables.
General characteristics early spring plants.
Plants require sunlight for normal functioning. It is in the light that the processes of photosynthesis occur, when organic substances are formed from inorganic substances, which are then used by plants for their development.
In the April forest, the trees and bushes have not yet put on their leaves, and nothing prevents the sunlight from penetrating to the very ground. This is precisely the main reason that many plant species, in the process of evolution, “chose” early spring for their development.
In addition, after the snow melts, the ground is saturated with moisture, which is also a necessary condition for the normal development of the plant organism.
Already from the moment the snow melts in the forest community, already developed stems with young, slightly green leaves, as well as formed buds, can be observed in many plants. This group of plants has another developmental feature. In the second half of summer and autumn, early spring flowering plants experience a significant increase in renewal buds with the separation of the inflorescences contained in them. The growth rate of dots increases as autumn approaches. During winter months In the flowers of early spring plants, both pollen grains and embryo sacs are formed. No impact for a certain period of time low temperatures early spring plants do not develop. Even in cases where the soil in the forest freezes for real, the young parts of the plants do not freeze. This phenomenon is explained by the fact that the freezing point of cell sap in overwintering plants is significantly below 0C. In wintering organs, starch is replaced with sugar. Sugar concentration is high, freezing point is lower.
All early spring flowering plants are perennials; many store reserve nutrients in tubers, bulbs, rhizomes, and the core of the stem for quick and early flowering.
Plants also use the “transparency” of a leaf-free forest for pollination. In a bare spring forest, nothing prevents the wind from transferring pollen from male flowers (collected in “dusty” earrings) to female flowers, consisting of only small sticky pistils. This is very typical for trees and shrubs that bloom in spring. Another interesting phenomenon is spring forest– wind-pollinated grasses, for example hairy grass. Its flowers are small and inconspicuous, but the absence of other herbs and the massive accumulation of these plants allows it to be pollinated. 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 twilight of the summer forest? And in the spring, when lower tiers the forests are well lit; the most visible ones are yellow (anemone), blue (violets), violet (tennivora, corydalis) and pink flowers.
But all the favorable spring factors are most fully used by small plants classified as “ephemeroids”.
Ephemeroids- This is a completely special group of plants with unique habitats. In short, these are those plants that, having underground organs, go through their annual growing season as quickly as ephemerals. The word “ephemeral” is associated with something beautiful, but fleeting and short-lived. In our forests, their “hasty” life is associated with a sharp change in the light flux. If in early May the illumination and temperature in the forest are comparable to the illumination and temperature at open areas, then at the height of summer the forest is both darker and colder. This interferes not only with the normal development of plants, but also with the normal life of pollinators. (Biology at school. No. 1 1994 // Spring phenomena in the life of plants, p. 63)
An example of them could be various types corydalis, goose bows, anemones. They are born immediately after the snow melts. It is quite cool at this time of year, but the ephemeroids nevertheless develop very quickly. After a week or two they are already blooming, and after another two to three weeks their fruits and seeds are already ripening. At the same time, the plants themselves turn yellow, lie down on the ground, and then their above-ground part dries out.
All ephemeroids are perennial plants. After the above-ground part dries out, they do not die. Their living underground organs are preserved in the soil: tubers, bulbs, rhizomes. These organs are receptacles for reserve nutrients. It is due to this building material This is how ephemeroids develop quickly in the spring. With such a short growing season, and even with an unfavorable spring temperature conditions it is impossible to accumulate many nutrients necessary for the development of tall and powerful stems and large leaves. Therefore, all our ephemeroids have small sizes. (Petrov V.V. Flora our Motherland. M: Enlightenment, 1991, p.63).
Perennial early spring flowering plants have another problem - seed dispersal. By the time their seeds ripen, the trees and shrubs have already become covered with leaves and have risen summer herbs. There is practically no wind in the forest, so spreading seeds with its help is not effective, and you can’t reach animal fur. They also don’t have time to ripen juicy berries that forest animals would feed on. But what is always in abundance in the forest are ants. On the fruits or seeds of these plants special fleshy appendages rich in oil are formed - elaiosomes ( from 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 dubravnaya.
3. Anemone buttercup.
4. Goose onion.
5.English oak.
6. Creeping tenacious.
7. Chickweed.
8. Ash-leaved maple.
9. Lily of the valley in May.
10. Common hazel.
11.Coltsfoot.
12. Ozhika is hairy.
13 Spring compatriot.
14.Trembling poplar (aspen).
15. Dog violet.
16. The corydalis is dense.
17. Bird cherry.
Having studied the characteristics of these plants, I divided them into ecological groups 1) in relation to light; 2) in relation to hydration;
3) by pollination method; 4) ephemeroids; 5) according to life forms.
By attitude towards light It is customary to distinguish three main groups of plants: 1. heliophytes– (from the Greek “helios” - sun, “phyton” - plant) plants of open spaces, well-lit habitats; 2. facultative heliophytes– species that can live in full sunlight, but 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. The growth of plants in illuminated (or shaded) places does not always indicate their actual need for light.
By in relation to hydration.
Based on their ability to retain moisture, plants are divided into
1. Poikihydride These plants easily absorb and easily lose water and tolerate long-term dehydration. As a rule, these are plants with poorly developed tissues (bryophytes, ferns, algae). 2. Homoyohydrides– plants that are capable of maintaining a constant water content in their tissues; among them, different ecological groups are distinguished (Life of Plants, vol. 1, p. 76):
- hydatophytes– aquatic plants completely or almost entirely immersed in water;
- hydrophytes– water-terrestrial, attached to the soil near water bodies and on abundantly moist soil far from water bodies;
- hygrophytes– plants living on abundantly moist soils and at high humidity;
-mesophytes– plants living with sufficient moisture;
- xerophytes– plants that are capable of obtaining moisture when there is a lack of it, limiting the evaporation of water or storing water.
Ecological groups of early spring flowering plants in relation to light and moisture.
| Species name. | In relation to the light. | In relation to hydration. |
| Birch warty | Heliophyte | Mesophyte |
| Veronica dubravnaya | Heliophyte | Mesophyte |
| Anemone buttercup | Sciophyte | Mesophyte |
| Goose onion | Heliophyte | Mesophyte |
| English oak | Heliophyte | Mesophyte |
| Creeping tenacious | Heliophyte | Mesophyte |
| Chickweed | Heliophyte | Mesophyte |
| Ash maple | Heliophyte | Mesophyte |
| May lily of the valley | Facultative heliophyte | Mesophyte |
| Common hazel | Facultative heliophyte | Mesophyte |
| Coltsfoot | Heliophyte | Mesophyte |
| Ozhika hairy | Facultative heliophyte | Mesophyte |
| Sochevichnik spring | Sciophyte | Mesophyte |
| Trembling poplar | Heliophyte | Mesophyte |
| Dog violet | Facultative heliophyte | Mesophyte |
| Corydalis dense | Heliophyte | Mesophyte |
| Bird cherry | Heliophyte | Mesophyte |
Analyzing the collected data presented in the table, all the early spring flowering plants that I discovered - mesophytes, and all these plants are heliophytes, with the exception of the spring nomad, anemone buttercup - 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 wind-pollinated ones, when there is no foliage on the trees and shrubs yet. Male inflorescences can be many times larger than female flowers, solitary or in groups, in order to produce as much fine, dry and very light pollen as possible. They say about such flowering that the plant “gathers dust.”
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.
| Species name. | According to the method of pollination. | According to the length of the growing season. |
| Birch warty | Wind-pollinated. | |
| Veronica dubravnaya | Insect-pollinated. | |
| Anemone buttercup | Insect-pollinated. | Ephemeroid |
| Goose onion | Insect-pollinated. | Ephemeroid |
| English oak | Wind-pollinated. | |
| Creeping tenacious | Insect-pollinated. | |
| Chickweed | Insect-pollinated. | |
| Ash maple | Wind-pollinated. | |
| May lily of the valley | Insect-pollinated. | |
| Common hazel | Wind-pollinated. | |
| Coltsfoot | Insect-pollinated. | |
| Ozhika hairy | Wind-pollinated. | |
| Sochevichnik spring | Insect-pollinated. | |
| Trembling poplar | Wind-pollinated. | |
| Dog violet | Insect-pollinated. | |
| Corydalis dense | Insect-pollinated. | Ephemeroid |
| 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 life form as “the form in which the vegetative body of the plant (individual) is in harmony with external environment throughout his entire life, from the cradle to the grave, from seed to death” (Life of Plants, vol. 1 p. 88). Speaking about the harmony of the plant with environment, implies the adaptation of plants to the complex historically developed during the evolution of external factors, which dominate 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 feature - the location of renewal points from the surface of the earth, from which new shoots will develop:
1.Phanerophytes(Greek “phaneros” - open, obvious) - in this type of plant, the renewal points 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 ground. The above-ground part dies off in the winter. New shoots develop from buds located on bulbs, tubers or rhizomes that overwinter in the soil.
3. Hemicryptophytes(Greek “hemi” - semi-, and “crypto” - hidden) are herbaceous plants, the renewal buds of which are located above the soil level, often under the protection of fallen leaves and other plant debris.
4. X amephytes(resume 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 a visual accounting of the frequency of occurrence of species, which I displayed in the table.
| Plant species | Life form | Frequency of occurrence | Habitat |
| Birch warty | Fanerofit | Often | Surrounding forests |
| Veronica dubravnaya | Geophyte | Often | Wastelands, forest edges. |
| Anemone buttercup | Geophyte | Rarely | Thickets of bushes. |
| Goose onion | Geophyte | Often | Arable lands, forest edges, slopes, ditches. |
| English oak | Fanerofit | Moderately-often | Surrounding forests. |
| Creeping tenacious | Hemicryptophyte | Moderately-often | Surrounding forests. |
| Chickweed | Geophyte | Often | Surrounding forests, edges. |
| Ash maple | Fanerofit | Rarely | Forest edges, populated area. |
| May lily of the valley | Geophyte | Often | Surrounding forests, edges. |
| Common hazel | Fanerofit | Often | Forest edges. |
| Coltsfoot | Geophyte | Often | Ditches along roads, fields. |
| Ozhika hairy | Geophyte | Often | Surrounding forests. |
| Sochevichnik spring | Geophyte | Often | Surrounding forests. |
| Trembling poplar | Fanerofit | Often | Forest edges. |
| Dog violet | Geophyte | Moderately-often | Surrounding forests, edges. |
| Corydalis dense | Geophyte | Rarely | Forest edges. |
| Bird cherry | Fanerofit | Moderately-often | Forest edges. |
Conclusions.
Based on the research:
1. 17 species of early spring flowering plants were discovered.
2. Most of these plants are found moderately often and often in the area around the village.
3.Basic environmental groups these plants are:
- in relation to light – heliophytes;
- 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. No protected plants were identified among the early spring plants.
Conclusion.
During 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 mass collection, especially those species that have beautiful flowers(crested flowers, anemones, corydalis). 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 are not included in the endangered lists.
I intend to continue my work, since it seems to me that I have not yet become acquainted with all the plants of this group.
The results of my work can be used by 6th grade students 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. Flora of our Motherland. M: Education, 1991.
3. Tikhomirov V.N. Determinant higher plants Yaroslavl region. Yaroslavl, Verkhne-Volzhskoe book publishing house, 1986.
4. Biology at school No. 1. 1994 // Shipunov A.B. Spring phenomena in the life of plants.
5. Biology at school No. 2. 1998 //Klepikov M.A. Primroses.
6. Biology at school No. 2. 2002 //Antsiferov A.V. Early spring field trip with sixth graders.
