The flower broke through the asphalt. Like a flower breaks through the asphalt
I ENVY THE POWER OF LIFE AND THE ENERGY OF THESE FLOWERS GROWN THROUGH THE ASPHALT.
You have probably seen grass breaking through the asphalt. This amazing phenomenon can be observed at every step: a soft, weak blade of grass breaks through hard asphalt. Maybe the asphalt cracks for some other physical reason, and the plants grow through the crack? Maybe a seed germinates in a small amount of soil on the surface of the asphalt, and then destroys the asphalt with its roots? And if, nevertheless, a blade of grass breaks through the asphalt, then by what forces?
How does a weak blade of grass break through the asphalt?
Initially, the seeds actively absorb water, swell and begin to germinate. Huge hydrostatic pressure arises in the cells of the seedlings, which allows them to overcome the thickness of the earth, and if necessary, the asphalt.
Plants have special adaptations that help them break through the ground. A sprout of corn, for example, breaks through the ground with tightly folded leaves, like an awl. Plants with a massive top (bean sprouts) overcome the resistance of the soil with the end of the stem bent twice. In castor beans, the stem is twisted in a loop to lift the clod of earth lying on top.
Swelling pea seeds are even used by anatomists to separate the bones of the human skull, which are connected by a jagged suture, and this requires a very large force.
Seed sprouts show pressure up to seven atmospheres.
Desert champignons break through the hard asphalt-like crust of desert takyrs. Common champignons break through concrete and asphalt pavements of roads and sidewalks, concrete floors of garages and warehouses. In 1968, a large family of champignons broke through the asphalt in the very center of Moscow, near the Bolshoi Theater. The hyphae of some fungi are capable of drilling into thin plates of marble, limestone, and gold. This penetration is purely mechanical, due only to the enormous intracellular pressure of the developing hyphae. During the growth period, the turgor pressure in mushrooms greatly increases, the tissues of the fruiting body become extremely elastic. This pressure reaches seven atmospheres and is equal to the pressure in the tires of a ten-ton dump truck.
This world is beautiful
This world is cruel
Broke through the asphalt
Little sprout.
"Hands" pulls to the sky,
Rises to the top
Tearing through the stalk
Suffocate the shell.
That's the way fate is
Opposite to go.
He was born in the city
And not in the spacious steppe.
It doesn't scare him
He boldly goes forward
Where there is a piece of heaven
Among the iron heights.
And the city retreats
He didn't have to argue.
mighty strong tree
Born in that city.
The germ of chastity is thin
Words strengthen nipples
A strange cold runs through the body
And the woman is torn to pieces.
Opening bodily sprats
Tomato stained knives
Not many can be trusted
Only those who flow from love.
Patting heartily on the ass
Dreaming of big feelings
Giving each other forever
Let out a frenzy cry.
There is the eternal torment of intercourse
There is a female, ordinary cry.
Primal matter hunger
Forced zeal, a dead end.
The secondary soul of obsession
Satiation with a solid body ...
Through a lethargic dream
Began to trace the summer
With a pack of empty cigarettes
I imagined until dawn.
Memory will create mirages
As if in mockery, in the desert
Instead of cold water
A glass of alcohol was offered.
By the way came etude
Worth throwing or not worth
Smoke came out of my ears
I'll make tea, tea will help.
Enough apathy, Scythian!
Bitterness in the head, like in a jug
She's spacious, fresh
It's hard to get to this day.
Mind tired of tasks
Glitter pyramids, pharaohs
The power to divinely lie
To...
Through time and distance
The planet's ball flies into the darkness.
He drinks the warmth of a shining star
That she could become the sun for him.
Becoming a home to the human tribe,
He gave them a place to live.
But to live closely, on it is huge,
They, a small body, great evil.
And the cosmos looks indifferent,
The earth's ball is small, negligible in it.
And eternity will take our souls,
When we leave the body.
And vain vanity,
In the bodies of the born will be life.
And the rank in this world is mortal,
Don't be proud of your height.
Through the times...
Have you seen the miracle yet?
Never seen a miracle?
That's the trouble - I did not see a miracle!
So go and have a look.
You will see a miracle
Amazing Miracle:
Where the store "Dishes"
Near house number three,
Through the asphalt at the crossroads
The birch breaks through.
(Roman Sef)
You must have seen when a timid sprout of grass appears in the middle of the asphalt, a young shoot of a tree or a flower blooms. Stop for a moment and think what force makes a weak plant to make its way through hard ground and break a stone.
Or maybe the sprout did not break through the asphalt at all, but successfully used the existing crack to climb up? What if it was the wind that brought the seed into the asphalt crack, and, stuck there, found enough earth and moisture to germinate? Or did "little Hercules" raise the stone block himself?
To understand this, we note that the seeds could germinate, hitting the paved section of the road in various ways:
1. With the help of the wind. This is how dandelion, poplar, maple, plantain reproduce. There is always enough dust on the roadsides - it is enough for a bush of some small plant to settle there.
2. Clinging to animal hair, bird feathers or people's clothes, along with dirt on car tires, etc. (for example, prickly burdock blossoms).
3. Traveling in the digestive systems of animals and birds (viburnum, wild rose, oak).
Seeds can"punch through» asphalt and from below, if:
1. The plant reproduces with the help of rhizomes (wheatgrass, euphorbia vine, plantain).
2. Seeds fell under the asphalt during road repairs, especially if they have the ability to “preserve” and germinate a few years after they were covered with asphalt and cracks appeared in it.
Interesting! Up to 1500 seeds ripen from one blue cornflower flower. In a dry state, they remain viable for three to ten years. The seeds of ginseng, orchis, lily of the valley have the same properties. While in the soil, they create a natural seed bank and wait for favorable conditions (defects in the asphalt - why not) to germinate.
However, 10 years is far from the limit. In Manchuria, a case is known of the germination of lotus seeds, which have lain for several hundred years in deep silty layers of soil.
You are probably already impatient to find out what kind of magical power pushes a tiny sprout to exploits? I answer - fluid pressure inside cells.
Once in warm, moist soil saturated with oxygen, the seeds actively absorb water and swell. The absorption of water occurs with great force. For example, cocklebur absorbs water with a pressure of 1000 atmospheres.
The pulling of water from a moist environment (soil) into a dry seed or sprout cell is called osmosis.
Due to the increase in the amount of water, hydrostatic pressure arises in the cells of the plant, which makes it elastic and resistant. Botanists call this pressure turgor(translated from Latin - "filling").
It is turgor that supports the leaves and stem of the plant, giving it hardness and strength. That is why the sprout becomes so bold that it can even break through asphalt, and its roots easily break through hard earth and stones. When the level of turgor decreases, the plant wilts.
Due to the enormous internal pressure - turgor - ordinary champignons become so elastic that they can destroy not only asphalt, but also, for example, the cement floor of warehouses. The hyphae of some fungi easily destroy thin marble and gold plates.
Seeds are often tricked using various methods to germinate faster and hold onto the ground more firmly. When other seeds obediently wait until the rain fills them with silt or someone accidentally tramples them into the soil, the seeds of wild oats and feather grass, like a drill, burrow into the ground on their own and sprout roots.
The corn sprout easily cuts through the ground with densely folded leaves. And the root, meanwhile, rushes deep into. Legumes sprout, bent in half, as if they want to double the strength of the stem. And the castor bean sprout even forms a loop to lift the clod of earth "over your head."
Germinated seeds behave like wedges: they find weak spots in the soil, press on them and push the particles of the earth apart. The thicker the stem becomes, the wider the crack.
It is curious that mankind used the wedge in ancient times. Bronze wedges were used by the ancient Egyptians to break off blocks of stone for the construction of the pyramids.
The use of wooden wedges is also known. One of these was hammered into a stone and poured with water until it swelled. Wet wood pressed with such force that it simply tore apart the rock. Doesn't this remind you of anything? That's right, it also breaks stones and a sprout that seeks to break out of the ground.
So we learned how a fragile sprout breaks through the firmament. In the end, I just want to add that during the preparation of the material, not a single asphalt surface was damaged. =)
Between asphalt and stone
Business establishments, shops, theaters, museums, etc. are usually concentrated in the center of a large city. Dense high-rise buildings, continuous pavement of the roadway and sidewalks with asphalt (concrete), heavy traffic - all this makes the central areas the most "urbanized" and difficult for penetration and life of plants. In addition, cleanliness is usually most strictly maintained here, and the flow of freight transport is limited, with which plant diasporas could be brought. At first glance, the flora obediently occupies only the places allotted to it - planting trees and shrubs along the streets (on the boulevards - also on the dividing strips) and in the yards; squares, lawns, flower beds; various temporary devices such as portable concrete containers with decorative flowering species or small shrubs.
But even in these very unfriendly conditions, plant life penetrates against the will of man, as soon as there is a patch of free land somewhere, a crevice between facing stones, a crack in the asphalt, in which dust and soil particles can accumulate. Such an ecological "micro-niche" can already serve as a haven for alien settlers, if only there was somewhere for seeds to germinate and where to take root. Walking slowly through the streets, you can make interesting botanical finds in the city center. Here, for example, in early spring, as soon as the snow is removed from the sidewalks, young needles of green grass break through in the cracks between the sidewalk and the wall of the house. These are the leaves of various perennial grasses, most often from the bluegrass and fescue genera. Dandelions, goose cinquefoil and other herbs common in meadows and roadside habitats often settle here. You can also find seedlings of tree species - maple, poplar, linden, but they, of course, are doomed to death and only in rare cases will live for several years.
These plants, making their way through the hard surfaces of urban sidewalks, have rightfully earned the name "asphalt crackers"
An interesting group of urban settlers are plants - "asphalt crackers", to which a number of works are devoted in botanical literature. It happens that in the soil layer under the asphalt favorable conditions are formed for the seeds or rhizomes found there. Obeying negative geotropism - the force that causes the seedlings to stretch upward against gravity, they break through the asphalt, literally cracking it. An amazing picture is presented by the grass breaking through the asphalt, but this phenomenon is even more amazing if you think about its mechanism: how can young leaves, consisting of soft, juicy tissues, overcome the barrier of almost stone hardness? The answer lies in the force that seedlings develop when growing cells and tissues suck up water by osmosis. The resulting turgor pressure is hundreds of kilopascals (tens of atmospheres), which is why asphalt cannot resist the rapid growth of grass. (Such examples can also be observed in natural conditions - in early spring in the forest, sprouts of "snowdrops" pierce pieces of old wood and other solid barriers. It is known that the turgor pressure of germinating seeds was used in ancient times for technical purposes: when it was necessary to separate a stone block from a rock, peas were poured into the crevice and filled with water.)
In the role of asphalt crackers, you can meet not only typical "citizens" (dandelions, plantains, etc.), but also plants from the surrounding landscapes, especially if the outskirts of the city are very close. Among them are ordinary field weeds: wheatgrass, sow thistle, thistle, wood lice. The author also happened to observe the city of Elista (Kalmyk ASSR), how one of the inhabitants of the surrounding semi-desert, Austrian wormwood, cracks the asphalt. Yes, it hacks so that pieces of asphalt fall off the resulting crack, yielding to the pressure of young leaves of sagebrush, so seemingly innocent; soft and silky...
Of course, it is easiest to germinate where the asphalt is of poor quality, but the "crackers" themselves successfully contribute to its destruction.
The number of species-burglars is quite large: for example, in Ryazan they counted more than 50, in Pushchino near Moscow - about the same number. It is curious that not only plants, but also fungi are capable of cracking asphalt. It turns out that delicate mushroom caps develop considerable pressure as they grow. And the most powerful crackers are shoots and root shoots of trees, especially poplars. According to botanists, if pedestrians had not trampled sidewalks, then in some areas whole thickets would soon appear on them.
But in search of botanical finds in the city center, you should not look only at your feet. Looking up, you can see that urban plants are sometimes forced to leave their usual ground habitats and look for suitable conditions for settling and surviving in the most unexpected places. So, often various herbaceous species grow on stone walls and fences, especially often in those ancient cities where fortress towers and walls have been preserved. Moreover, many take root here for a long time (of course, perennials) and, together with cushions of mosses and lichens, form peculiar plant groups, other settlers are random and short-lived. Here is an example of a plant "population" on the fortress wall in Han (Czechoslovakia): on a small layer of fine earth formed as a result of weathering, entire communities of juveniles, various types of stonecrop, dandelions and other perennials grow; between them, small annuals-ephemera and various weeds find shelter. The wall vegetation of Italian cities is rich, where ancient fortress walls, stone fences of gardens, terraces are covered with a motley mosaic of plant microcommunities. It is curious that the unusual habitats of some of the species growing here are also reflected in their names: such are the parietal, wall asplenia fern, wall cymbalaria, etc.
Even trees grow on the ruins of the fortress walls. One of them was immortalized by M. Lermontov:
So in the crack of the ruins sometimes the Birch grows young And green, and amuses the eyes, And adorns the gloomy granite. (...) And the alien stranger Regrets her fate. Defenselessly devoted To the gust of storms and heat, finally, She will fade prematurely; But a whirlwind will never uproot My birch: it is hard (...) ("June 1831, 11 days")
There are many other places in cities where you can unexpectedly meet plants. So, there are times when small grasses, shoots of trees and shrubs settle on the monuments and you have to take care of the "weeding" of urban sculpture. In Leningrad, a city rich in rivers and canals, plants (cereals, shoots of willows, etc.) find shelter in the cracks between the facing slabs of the embankments. On the granite turrets that adorn the Staro-Kalinkin bridge across the Fontanka, young birch trees turn green in spring and summer.
Sometimes small shrubs and even trees grow at an unusual height for them - on balconies and ledges of walls, under attic windows, on roofs and brick chimneys. It is not difficult to guess how they got there: the seeds of some species (elder, mountain ash) were brought by birds, others (birch, aspen, willow) - by the wind.
I have a green willow on the seventh floor, on the balcony. If the wind, then the shadow from its branches walks like a wall; it is very disturbing and very freedom-loving - the restlessness of nature living next to me! The wind bends its branches and bends them down zealously, as if it wants to return it to ordinary, earthly life; but - with me is my willow, a green flexible willow, in the freezing cold and in the unquenchable heat ... The critic will pass by, grinning contemptuously, crookedly: "Eco marvel! all the willows everywhere turn green in the spring!" Yes, but not on the seventh! and it really is a marvel that, having parted from the forests, she settled with me! (N. Aseev. "Willow".)
We have already mentioned above that the species composition of wild plants in the center is poor compared to other ecological zones of the city. Plants settle here only for a short time - as long as they manage to hold out until the broom of the janitor or the brushes of the harvester. True, although the settlement of plants is constantly renewed, the flora is quite constant: dandelion, annual bluegrass, goutweed, kupyr, ivy-shaped budra, deaf nettle, etc. These, on the one hand, are the most unpretentious and hardy species, and on the other, their rudiments can constantly penetrate from neighboring areas of the city with richer flora - from lawns, park lawns, etc.
Wherever dandelions are attached in the city: a fragment of a metal structure can also serve as a "flower pot"
The poverty of the flora in the center of the city is a kind of comforting indicator of its sanitary and hygienic state. As researchers of urban flora wrote, the "good city" actively resists the introduction of plants. And only in difficult times of wars and post-war disasters, when the "cultural habits" of the city weaken, do weed and ruderal species (companions of human habitation and inhabitants of wastelands) penetrate even into the central regions. We have already mentioned that in 1921 in the center of Petrograd, near the Rostral columns, more than a dozen species of weeds could be found.
Delicate leaves of mosses (unlike leaves and flowering needles) are not protected by a cover film - cuticle, do not have stomata, which could partly regulate the flow of substances from the external environment. Mosses absorb pollutants over their entire surface, and since their leaves are very thin, this surface is huge (and in many species it still increases due to the development of various outgrowths and hairs). Most atmospheric pollutants (and especially sulfur dioxide) are detrimental to the very first stage of development of mosses - protonema, germinating from spores, and therefore greatly inhibits the processes of their reproduction and settlement. It is significant that during the artificial transplantation of small sods of mosses from the forest to the most polluted areas of the city, leaves of many species quickly turn brown, the tops of the shoots die off - under the microscope, pictures of the destruction of cells and chloroplasts are visible. These phenomena are described in various industrial cities - both in the Ruhr region of Germany, and in such a remote region as New Zealand (Christchurch).
Unfavorable for mosses is such a feature of urban conditions as artificial salinization of soils and other substrates. It is known that under natural conditions, mosses - a group that is generally very widespread - avoid saline soils (for example, they are absent in deserts with chloride salinization, and they are extremely rare on sea coasts).
It is clear that the abundance and diversity of mosses - both epiphytic and living on inorganic substrates - sharply decrease in the most unfavorable areas of the city in terms of environmental conditions. Ecologists in West Berlin had to draw up a special "Red List" of urban mosses and liverworts, since it turned out that over the past decades, one third of their species have disappeared completely, and a quarter are on the verge of extinction or in a threatened state.
Another group of spore plants - lichens - has no less complex relationship with urban conditions. Lichens and the city is a topic extremely popular in modern ecology: many symposiums, hundreds of publications, and more than one solid monograph are devoted to it. To approach it, let us first recall some of the biological characteristics of lichens, on which their vitality in cities depends.
Lichens are a group that is very diverse in relation to environmental conditions. They can live on a variety of substrates: on other plants (epiphytic species), on soil, organic remains, on stone, etc. In cities, they settle not only on tree trunks and branches, but also on the roofs and walls of buildings, stone and wooden fences, and even on bronze and cast-iron gratings, and monuments. There are peculiar urban habitats that are especially attractive to certain groups of lichens. So, it has been noticed that in places of mass accumulation of pigeons (on the railings of bridges, monuments, etc.), nitrophilic (nitrogen-loving) lichens willingly settle - just like on islands with "bird markets". Thus, suitable substrates in cities for lichens are sufficient. And if in the central regions the set of lichen species is very poor, then it is not the lack of substrate that is to blame, but all the same industrial, transport and other pollution, from which lichens suffer even more than mosses.
The reasons for the special sensitivity of lichens lie in their structure and physiology. As symbiotic organisms, consisting of branched fungal hyphae and unicellular algae included in their network, lichens have a huge inner surface. Therefore, their absorption capacity is very high: like a sponge, they absorb pollution from the air; and especially with rainwater (at the same time throughout the year). Since lichens grow extremely slowly (the growth is only a few millimeters per year), they do not have the ability to quickly "dilute" the absorbed substances due to the formation of new plant mass, and therefore the concentration of pollutants in the lichen thallus gradually rises to dangerous limits. Particularly toxic are chemical compounds that acidify the environment, since the life processes of symbiont algae are strongly inhibited. In this regard, the main enemy of lichens is sulfur oxides (primarily SO 2, which gives sulfuric acid when dissolved in water). As early as the beginning of the 20th century. "cleansing" of tree trunks from lichens along the railways was noticed. The explanation is very simple: SO 2 is a significant part of the emissions generated during the combustion of low-grade coal with an admixture of sulfur in locomotive furnaces.
The sensitivity of lichens to urban air was first discovered in the middle of the last century when studying the lichen flora (species composition of lichens) in the Luxembourg Gardens in the center of Paris. To the surprise of botanists, it turned out to be much poorer than in the surrounding area. Since then, there have been many cases to be convinced of the "disgust" of lichens for the urban environment: by the beginning of the 1980s, the lichen flora of almost 100 cities of the world was studied, and similar patterns were found everywhere, which are clearly visible on the "lichen maps" of cities. In a typical large city, there are several concentric zones with different abundances of lichens. Their names are quite expressive: in the center - "lichen desert" (single species or complete absence of lichens), further - "zone of struggle" (there are more species, but many of them are kept on the verge of existence), and only on the outskirts of the city does the zone of "favorable conditions". From the outskirts to the center, not only the number of species decreases, but the total abundance of lichens also decreases. Both indicators can be calculated and measured; on their basis, various "lichen formulas" have been proposed, which make it possible to judge the degree of pollution of the urban atmosphere.
However, not only industrial and transport emissions "expel" lichens from the most urbanized areas. To a certain extent, the great dryness of the air is to blame for this, and for epiphytic lichens, the small number of trees in the city center is also to blame.
One way or another, but to get acquainted with urban mosses and lichens, you should not go to the central part of the city or its industrial areas: here only random and meager finds await the city dweller. Clean, not overgrown with mosses and lichens, the trunks of city trees, pleasing to the eye with their well-groomed appearance, are in fact a formidable sign of the unfavorable air environment in the city.
An overview of the flora of the city center would be incomplete if we did not note that here (as in other urban areas) there is always plant life in other forms, sometimes we do not notice. This, for example, is a raid of algae and small sods of moss on the walls and roofs of houses. Some species "attach" even on the walls of underground passages and transport tunnels (of course, where lighting is still available). In Leningrad, a very unusual habitat of small mosses from the genus Polia was noted - in the edging of trolleybus windows (though only in very wet years). Finally, there is a form of plant life that is invisible without a microscope: this is the so-called aeroplankton, rushing through the air and settling on walls, roofs and pavements. It contains pollen and spores of plants, fragments of fungal hyphae. However, there are cases when it becomes noticeable to the naked eye; this is, for example, the pine pollen already mentioned in the previous section, which covers the puddles on the asphalt with a thin yellowish powder during the mass flowering of pine.
Until now, we have been talking about the "unorganized" plant world of the city center. Let us now turn to the forms of vegetation most familiar to the townspeople - those created by man. This is urban landscaping, which, according to urban architects, is part of the urban infrastructure.
Within the framework of this book, we can very briefly mention only the main (by no means all) forms of gardening in the central zones of cities. For a detailed acquaintance with their composition, structure, methods of creation and care, we refer the reader to the guides on urban green building and gardening art, listed in the list of recommended literature.
Recall what are the most common types of urban plantings.
city parks can be characterized by the following definition: "Park - a combination of green spaces (and usually architecture of small forms) with roads, alleys and reservoirs, designed to decorate the area where people rest" * . The specificity of urban parks is only in their location (inside the city) and in various forms of use (parks of culture and recreation, attractions, children's, zoological, memorial, etc.).
* (Reimers N. F., Yablokov A. V. Dictionary of terms and concepts related to the protection of wildlife. M., 1982. S. 86.)
Gardens- inner-city plantings of smaller sizes, intended for short-term walks, inspection, and quiet rest.
squares- one of the most common forms of urban gardening. These are small (up to 1.5-2 hectares) plots of territory, planted with trees, bushes, lawns, with open passages, convenient for short-term rest "on the go".
boulevards- landscaped strips along the streets and embankments, with separate paths for pedestrian traffic.
Ordinary landings along the streets is also a very common form of landscaping. For planting along the pavement, a single tree species is usually used, often in shorn form, sometimes accompanied by shrubs and a strip of lawn.
Intra-quarter plantings in the city center - these are very small patches of vegetation (sometimes only a few trees and shrubs, or even a single tree - tapeworm) in the courtyards of residential buildings or in front of them, on separate unbuilt "spots", etc.
Vertical gardening- climbing and climbing plants on the walls and special supports, as well as ornamental plants on the balconies of buildings.
This short list does not include all varieties of urban green spaces; for example, various plantings at public buildings and institutions are not mentioned.
In recent years, in many large foreign cities, another form of gardening has become widespread - the use of ornamental plants (not only flower crops, but also trees and shrubs) in mobile containers - large concrete or stone vases. Actually, the use of trees in tubs for these purposes is not new: they decorated both the courtyards of ancient houses and the terraces of country palaces of Russian tsars. However, only in our time, plants in containers ended up on noisy and gassed central city highways, where they are delivered from special storage greenhouses. Trees and shrubs in containers are placed on paved areas: in squares near fountains, in urban pedestrian zones, etc., sometimes creating entire "mobile gardens". The ability to remove plants for the winter makes it possible to use heat-loving southern exotics with this form of landscaping (for example, in the city of Freiburg in Germany, oleander, laurel, and palm trees grow in containers on the streets). And if the plants do not stand in the city air for a long time (there are damage to the leaves), you can send them "to rest" in greenhouses, replacing them with fresh specimens - according to a kind of "shift method".
Experts write with sympathy about container culture as one of the easiest ways to green cities. But it is worth recalling that the plants themselves do not live easily - in complete isolation from the natural soil, mainly on artificial irrigation, with a forcedly limited volume and suppressed growth of root systems. It is not for nothing that trees and shrubs in a container culture cannot reach large sizes.
Both in the central districts of the city, and in urban and suburban parks, we now and then encounter such a peculiar anthropogenic form of urban vegetation as lawns. It deserves a separate story.
It is difficult to imagine urban gardening without lawns. The gaze of a city dweller stops with pleasure on a flat carpet of fresh greenery, reminiscent of spring meadows and fields, even when spring is already far behind. Both poets and doctors unanimously testify that the greenery of herbs has a beneficial effect on tired eyes and the emotional state of a person. So, in the famous medical credo of the Salerno School of Health (XVI century) we read: "Sources smooth surface and grass - consolation to the eyes." And today, even the authors of serious scientific and practical guidelines on gardening do not spare poetic epithets when describing "soft, thin, delicate, bright, fresh, emerald green" lawns.
Where did the custom to create mowed lawns near buildings, on the streets, in parks come from? According to some authors, it dates back to medieval times. Around the feudal castles for defensive purposes, in order to prevent the enemy from sneaking up, forests were destroyed and open meadow areas with mowed grass were created. Subsequently, such plots, as a decorative element, also penetrated into cities and estates. Other authors believe that lawns arose much earlier and for other reasons, purely aesthetic. So, it is known that the art of creating and maintaining mowed lawns was developed in ancient China, the Mayan and Aztec states.
Nowadays, there are many types of lawns, differing primarily in purpose and use. Decorative lawns, as the saying goes. name, are used in urban landscaping mainly as an element of decoration. These are ordinary lawns on the streets, boulevards, in squares, and more formal and extensive parterre lawns, and motley Moorish lawns with a mass of multi-colored flowers (Alpine poppy, esholcia, marigolds, petunia), etc. Sports lawns with elastic and elastic grass cover (moreover, wear-resistant) are used on racetracks, football and other playing fields. So, in England, golf courses covered with lawn vegetation are very common; their sizes sometimes reach 30-50 hectares, and the total territory occupied by them in the country is estimated at a solid figure of 60 thousand hectares. Lawn coatings are also used for technical purposes: to strengthen and protect the slopes of highways and railways, on airfield fields, etc., as well as to absorb pollution near industrial enterprises.
From a botanical point of view, a lawn is a kind of meadow vegetation artificially created by man. It has certain similarities with natural meadows. Like natural meadows, lawns are communities of perennial mesophyte grasses, which form a continuous dense grass stand in the above-ground part, and a turf of intertwined roots and rhizomes in the underground part. But there are also significant differences from meadow communities, for example, a much greater density of plants: when creating lawns, the density norm is tens of thousands of shoots per 1 m 2, while in meadows numbers of the order of 3-7 thousand are common. In natural meadow communities, herbage, as a rule, in a vertical section, it has a complex multi-tiered structure, since grasses of different heights grow together. The structure of lawn grass stands is quite simple - usually it is only one tier.
But perhaps the most essential feature of lawn life is frequent and regular mowing, the consequences of which (more on them below) affect the life of plants much more than annual mowing in meadows. In addition, often (to be honest) lawn plants are also forced to endure trampling (and for sports lawns this is an inevitable factor at all).
Since far from all grasses are able to endure the conditions of life on lawns, a person himself regulates the species composition of lawn communities, selecting the most resistant species. And this composition, of course, is incomparably more limited than in natural meadows. So, in the upland meadows of the European territory of our country, 200-250 species grow (often found, not counting rare finds), and among the recommended lawn grasses - no more than 30-35, of which 5-10 species are especially popular.
Landscapers make rather strict requirements for lawn grasses. They should sprout together, grow quickly and form a strong grass-turf cover, give many shoots (including after frequent mowing) and be able to grow in a dense herbage. And with all this, invariably maintain decorative qualities and resistance to adverse weather conditions and diseases.
The composition of lawn grasses capable of producing a stable and decorative herbage has been selected over the centuries, as long as the techniques for creating lawn carpets have been developed.
The lawns of England are widely known. Usually, not without envy, describing the velvety English lawns, they refer to the humid and rather warm oceanic climate of this country, extremely favorable for growing grasses. Indeed, it makes it possible for lawn grasses to vegetate almost all year round and not lack moisture. However, it's not just the climate. According to one of the Soviet specialists who got acquainted with the lawns of England, there are also such components of success as a skillfully selected assortment of plants, the high skill of English gardeners, and excellent technical equipment. And here is the result:
However, as we read in K. A. Timiryazev, according to one Oxford gardener, it is not necessary to wait for three whole centuries. To the question: "How do you achieve such lawns?". He replied: "It's very simple, we constantly cut them, and from time to time we sow them; try to do all this, and in a hundred years you will get the same ones."
By the way, according to some experts, the "non-trampling" of English lawns is nothing but a legend. It's just that there is a well-established lawn repair system with turf plates, which is specially grown for this purpose in nurseries.
In our country, the best lawn plants are such perennial meadow grasses as meadow bluegrass, red fescue, meadow fescue, perennial ryegrass (aka perennial chaff), etc., from legumes - different types of clover. Sometimes in southern cities, on shady areas of lawns, creeping ground cover plants, such as periwinkle and even ivy liana, are successfully used. Among herbs, bluegrass is unconditionally preferred: this undersized grass, which forms numerous vegetative shortened shoots, is especially suitable for forming a dense grassy carpet with a strong, tear-resistant turf. It is also important for our climate that bluegrass, like other named herbs, has significant winter hardiness. All of them tolerate well such an indispensable condition of life on the lawn as regular mowing (and to keep the lawn in good condition, mowing once or twice a week is recommended).
For "consumers" of lawns, frequent grass mowing is a way to constantly keep fresh green colors and velvety lawn carpet. It is believed that the very origin of this technique is associated with the desire to always have the spring appearance of vegetation before our eyes, regardless of the time of year. For plants, shearing is a constant interruption of normal development, artificial maintenance in a juvenile (youthful) state, and, most importantly, a strong reduction in the working photosynthetic surface. As a result, the creation and deposition of organic substances needed by the plant for growth, overwintering, and regrowth are sharply reduced. We also add that mineral nutrients are regularly removed from the cut foliage, which leads to a gradual depletion of the soil.
What helps lawn grasses to successfully overcome the consequences of such an unceremonious interference in their life? Firstly, this is the ability to quickly grow new shoots after cutting, which is clearly visible in Fig. 12. And secondly, plants are rescued by such a curious and not yet fully explained phenomenon as increased photosynthesis in the remaining “cuttings” of leaves. (By the way, it was also found in other cases when part of the leaf blade is destroyed: in the "stubs" of tree leaves with severe insect damage, in the remains of grass leaves bitten by cattle on pastures, as well as in special experiments with the removal of part of the leaf from experimental plants .) And, of course, human help is needed, and above all, constant compensation for lost nutrients - regular fertilization. Other common lawn care measures are aimed at creating optimal ecological conditions (watering or draining, piercing the turf to improve air access, etc.) and maintaining lawn plant communities (seeding grass, removing weeds, repairing damaged areas of turf, pest control ). On poor soils with high acidity, mosses have to be destroyed, which impair the growth of grasses and the decorativeness of the lawn.
It is likely that as long as urban greening exists, lawns will enjoy the unchanging affection of citizens.
The aroma of mowed lawns creates the illusion of a village, awakens old pictures, leading somewhere far away ... ........................ Slowly people pass by and inhale the sweet smell of summer - how wonderful it is to meet nature and renounce worries for a moment! In our city haze and buzz, perhaps it really is a miracle to find the end of the missing thread that will take you back to the past. (D. Hovhannes. "The aroma of trimmed lawns".)
Recently, new places of "registration" of lawns in cities have appeared. So, in some countries, lawn coverings on the flat roofs of multi-storey buildings have become popular (including for the purpose of thermal insulation). In many public interiors, portable "foam-rubbed lawns" or portable "peat lawns" are used, designed for a short-term decorative effect (landscaping of exhibitions, trade pavilions, etc.). Abroad, the sale of rolled lawns-carpets with pre-sown grass seeds is also widespread.
An indispensable and very attractive element of urban landscaping are flower beds - decorative compositions made up mainly of herbaceous plants (less often shrubs) that have flowers of bright and various colors. (In everyday life, such plants are simply called "flowers", and in the press it often happens to read about "trees, shrubs and flowers", although, from the point of view of a botanist, this is not entirely true: after all, any plants bloom, unless they belong to We just notice and appreciate flowers as the most attractive feature of ornamental crops.) Deciduous ornamental plants with different foliage colors also participate in flower beds.
City flower gardens are diverse in size, shape, location and combination of plants. Here are some of the more common varieties.
flowerbeds- flower beds of any geometric shape, usually with. symmetrical bright pattern of flower crops, sometimes quite complex outlines.
Rabatki- flower beds in narrow and long beds, often located along streets, alleys, buildings, etc.
Arabesque- flower beds (usually from one species of flowering plants) in the form of narrow winding lines, forming an elegant pattern against the background of a mowed lawn.
Mixborders- mixed flower beds, in which species with different flower colors and different flowering periods are used.
stone flower beds("alpine hills", rockeries) - flower beds from undersized plants planted in combination with stones.
The set of types of flower beds is not limited to this. In urban landscaping, you can find a wide variety of flower arrangements - from colorful "calendars" and "portraits" to flower beds on the surface of reservoirs.
So, in the city center, the plant world basically appears before us in the form of urban gardening - organized, geometrically planned, well-groomed. But there are (albeit extremely rare) exceptions, when corners of natural vegetation are preserved in the very heart of the city. Such is the tract "Bald Mountain" in the geometric center of Kiev - once a place of grand ducal hunting, and from 1873 to 1976 - a closed territory. Complexes of forest and steppe floras, corners of broad-leaved forests and steppe vegetation are perfectly preserved here. In recent years, employees of the Main Botanical Garden of the USSR Academy of Sciences have been working to create "nature corners" (small squares using wild flora) in various parts of Moscow. In other cases, elements of natural vegetation are included in urban development systematically, during the construction of new cities.
As a flower breaks through the asphalt, so their friendship and their love were able to break through and grow in the terrible embrace of war. This is a short retelling of stories from the cycle "In the Arms of War".
The annotations mention the war between wizards and vampires. But, to be honest,
Vampires and wizards are there for the background, well, in some places, fantasy flavor, for the sake of the popularity of these concepts,
- in fact, all these stories are this cycle-parable about the relations of people from different nations, about their friendship, love, misunderstandings, reaching discussions, disputes, squabbles, fights, or, at the worst, before the war of two peoples. Everyone suffers from war and fights in one way or another, and in the case of friendship they are able to learn something valuable from others. Because each nation has its own unique beauty and wisdom. True, few were able to make friends or love there. But, in general, because of the rarity and difficulty of such relationships, they are both brighter and more valuable. Books are about them, although, alas, they are also about the war.
"Vlad, puzzled, looked around at the children of another nation… other nations… these strange creatures who still lived by some medieval notions such as honor and the value of a large offspring. He looked at them with mixed feelings... his thoughts were also confused... He could not understand whether he was amused by their stupidity, which for some reason they appreciate, or whether he envied them, because there were many serious things in their lives, which never existed in his life... This strange effect, when a child of one nation suddenly communicates seriously with children of other nations... when you realize that someone else sees life from some other side, appreciates some other facets... when suddenly you understand that in addition to your truth there is another truth, in addition to your treasures - other treasures ... and while you looked at life and believed that blue is blue, someone lived in some other place, in another world, and firmly believed that your blue is white...
This is a strange effect, when children of different nations are immersed in communication with others, exposing their essence, their hearts and their thoughts ... when, voluntarily or involuntarily, the collapse of your familiar world and a reassessment of values \u200b\u200bis suddenly begins ... creations, molded each separately according to individual ideals about truth and beauty, different souls ... this is a miracle of a meeting that can either happen or not happen ... these are cracks and knocked out pieces of your world, or even its complete collapse ... the deeper you are wounded and broken your world, the more painful it can be ... and sometimes the fear of it already prevents you from opening up to meet another, alien, unknown ... but it's a miracle when different worlds can meet, can touch, merge partly or completely ... it's a miracle when from two different, sometimes , completely opposite worlds, a new world is born... wisdom and values of both worlds merge in it... the one who gets into it will be enriched spiritually... this is the wisdom of the meeting, to when you start to think about what you believed in out of habit, according to the habit accepted in your world ... when you understand that there is another truth, that the truth is many-sided, many-sided ... when a new world is born from the alloy of the fire of shock and the ore of someone's wisdom and depth , a new look at the world and things familiar before ... when you yourself, consciously, begin to choose what you will now believe in, what you will now appreciate ... when you yourself already consciously choose your truth, which you will continue to follow ...
