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According to the calendar, autumn begins on September 1, but astronomers believe that from September 21 on the day autumn equinox. Phenologists, on the other hand, believe that autumn begins with the appearance of the first yellow leaves on the trees of the warty birch or drooping birch. This is usually noticeable on August 23rd. But I first noticed the appearance of yellow leaves on August 18 on birches, and on lindens on August 24. After the first frost, there were even more yellowing leaves, and leaf fall began near birch, linden, and aspen. And already on October 4, during the excursion, we noted that there were no leaves on the poplars at all, the leaves on the birches were preserved in very small quantities. Partially there were still leaves on the oak near the school, on the maples. But the Canadian Norway maple has already completely lost its bright red outfit. We noticed that there are still a lot of leaves in the willow, in the lilac. They are still quite green. Full coloration of the leaves occurs when the bulk of the leaves have changed from green to color. For example, rowan on September 18, maple on September 20. The beginning of leaf fall is the day when the leaves fall even in calm weather or from touching a branch. For example, maple has September 14th. Massive leaf fall occurs when about half of the trees of each species shed their leaves. Full leaf fall is recorded when the trees lose all their leaves. Individual leaves are not taken into account. For example, bird cherry - September 22, linden - September 24, aspen - October 5, maple and birch around October 14. Ash, Canadian maple, poplar, alder, aspen can shed their leaves in one day. The sequence of leaf fall different trees different: the oak does not part with the leaves for the longest time, but the leaves appear on it later. There are oak trees that do not shed their leaves at all. So far, scientists have not been able to explain this phenomenon.
Leaf fall is not the same not only for different tree species, but even for representatives of the same species, depending on the growth conditions and individual characteristics. The timing of leaf fall is affected by the age and condition of the tree. Young plants shed their leaves much later than ripe and overmature ones. Sick trees affected by heart rot, as well as those affected by man or beast, lose leaves faster than healthy ones. In trees growing on the edge, in swampy and flooded places, leaf fall passes faster than in plants in dense forest. Needle-shaped leaves of pine, spruce have a small surface, their needles are hard, covered with a wax coating and therefore slightly evaporate water. They successfully endure winter drought, are very cold-resistant. In larch, the opposite is true, so it sheds its needles annually, as well as deciduous trees. In evergreens - lingonberries, cranberries, the change of leaves occurs in the spring. Cowberry leaves are hard, their stomata are only on the underside and near the curved edges of the leaf, so evaporation is negligible. At the wild rosemary, the leaf is pubescent from below, besides, the bushes hide under the snow in winter.
But for trees located close to electric lights, leaf fall begins later, since they have longer daylight hours.
Causes of falling leaves
Trees prepare for leaf fall in advance. Even in summer, a bud is born in the axil of the leaf petiole, and organic substances are deposited in the wood cells. Spring will come and due to these reserves, the bud will develop into a young shoot with leaves. By autumn, a layer of cells forms at the leaf petiole, which separates the leaf petiole from the branch; in autumn, the leaf easily separates from the branch and falls off.
Fall value
Leaf fall is the adaptation of plants to winter conditions. By dropping leaves for the winter, trees protect themselves from mechanical damage. Often in winter, during snowfalls, even large branches of trees break under the pressure of snow. There would be even more such breakdowns if the leaves did not fall off and trap snow on their surface. Leaf fall contributes to the removal of various mineral salts, a large amount of which accumulates in the leaves in the fall and becomes harmful to the plant. Leaf fall returns mineral salts to the soil. The leaves rot, and the mineral salts are reused to feed the plants. Hence, leaf fall depends not only on external, but also on internal causes, that is, it becomes necessary as a result of the vital activity of the plant itself. Where is the beginning of the phenomenon of leaf fall? From additional literature, we learned that such a peculiar adaptation of nature began to take shape. About 60 million years ago, when warm and humid climate of our places began to gradually give way to seasonal, with cold and snowy winter. Under the new conditions, only those trees and shrubs survived that went into winter with fewer leaves. So from generation to generation this important property of the leaf has developed.
Is it worth burning leaves in autumn?
The soil is covered with a layer of fallen leaves, branches, bark, dead grass. This layer is called the forest floor. AT deciduous forest litter annually is about 4 tons, and in pine forest– up to 3.5 tons per 1 ha. The forest floor has great importance in the life of the forest. The accumulation of humus and minerals in the soil, the development of biological processes depend on it. Loose litter easily decomposes and allows water to enter the soil, dense litter rots for a long time and has a sour smell. The bedding protects the soil and plant roots from freezing. The humus stains the soil dark colors, so these soils warm up better sunbeams, slowly cool down and thus create favorable conditions for life in the soil of beneficial microorganisms and plant roots. Cleaning leaf litter reduces planting growth by 11%.
Birches are deciduous plants, every year they shed their leaves in order to acquire fresh green “clothes” again in the spring. When does birch leaf fall end? This is often asked by students. Our material will help you understand this and learn a lot interesting facts about this seasonal event.
What is leaf fall?
The term, so familiar to everyone, refers to the biological process during which the leaves of trees, which have lost chlorophyll, are separated from the stems and fall to the ground. This process is characterized by the following features:
- In autumn, the trees take on a variety of colorful colors, from yellow and orange to crimson and crimson red. This happens because before the leaves fall, chlorophyll, the pigment that gives them green color.
- The leaves acquire the ability to easily separate from the branch even with a slight gust of wind due to the formation of a special separating layer that breaks the connection between the leaf and its stem.
- Due to this seasonal phenomenon, the trees are freed from those harmful substances that have accumulated in the leaves during the season of active growth.
- With the help of leaf fall, plants are protected from excessive loss of moisture, which is extracted from the soil in harsh weather. winter time becomes very difficult.
We have considered the main signs of the most important seasonal change in the life of trees. Now let's get acquainted with when the leaf fall near the birch ends, and also when it begins.
Birch
Early autumn is characterized by still warm weather conditions, the thermometer often has a positive value, however, precipitation in the form of drizzle and hoarfrost can fall. The trees begin to turn yellow, playing in the rays of the already dim sun with stunningly beautiful colors. In the first week of September, the thin-stemmed tree begins to lose its foliage.
The average duration of leaf fall depends on weather conditions and can be from 15 to 20 days. The answer to the question of in what month the birch leaf fall ended can be given as follows: September ( last days this month) or October (its first half).
Process Features
Birch is one of the first trees to lose foliage, along with aspens, maples, lindens. Considering when the birch leaf fall ends, it should be noted that by the end of October these beautiful trees standing completely naked. The fall of the leaves of the plant begins on September 15, completion - by about October 5, but it is impossible to name a more exact date - it all depends on natural conditions each specific year. The main activity of the process begins after the first frosts, which, as a rule, fall on the last days of September (from about the 28th).
Folk omens
We examined when the leaf fall near the birch ends. Why do people need this knowledge? First of all, observing nature is interesting in itself. However, there are also several folk signs, which were used by our distant ancestors to predict the weather. Some of them are interesting in their own way:
- If the leaves fall from birch and oak simultaneously and evenly, it is worth waiting for a mild winter.
- harsh winter expected if oaks and birches become bare in different time.
- The leaves turned yellow, but did not fall off by the time - there will be frosts.
- The leaves on the white-stemmed tree did not fall in the first week of October - the snow will fall late this year.
- The leaf fall is “according to the scenario”, the tree sheds its foliage in time - we should expect a long thaw at the end of January.
Unfortunately, it is impossible to accurately answer the question of what date the leaf fall of birches ends, however, everyone can determine the approximate time frame: the process of leaf fall of a traditional Russian tree ends by the end of September or the beginning (less often - the second half) October.
Katerina, city of Voronezh
Tell me, when does the period of leaf fall end at the apple tree, as well as mountain ash?
Leaf fall is a seasonal phenomenon in the life of trees and shrubs, which is observed from early autumn. Getting rid of leaves before the onset of winter cold, trees regulate the process of moisture consumption, significantly reducing its need. The process of leaf fall in different trees begins and ends at different times. This largely depends on weather conditions and the area where green spaces grow, as well as the types of trees and their age.
It is difficult to unequivocally answer the question when the time of leaf fall ends. It is noticed that first poplar leaves are lost, then oaks and mountain ash. Apple trees are slowly shedding their leaves, and even in winter on some trees, single leaves continue to flutter in the cold wind.
Trees at the time of leaf fall
Dropping leaves from trees serves another purpose - the crown under the snow cover has a significant weight. The branches of trees, especially young ones, are not able to withstand such a load. Fallen leaves can reduce the load on the skeletal branches of the tree, protecting the crown from damage.
Thanks to the process of photosynthesis, a large amount of harmful substances accumulate in the leaves by the beginning of autumn, which, with the onset of leaf fall, are removed along with fallen leaves.
The end of leaf fall in different tree species
Poplar
During the period of leaf fall, adult poplar trees lose a third of their leaves in the period from September 15 to 20, in the first ten days of October, up to 10% of foliage remains in the poplar crown. Completely lose poplar leaves by mid-October. Young poplars remain green longer than old trees, they turn yellow later and shed their leaves.
Oak
Oak leaves fall off in the first half of September, after about 30 days the trees completely lose their leaves. With early frosts, the timing of the end of leaf fall on oaks is reduced - trees quickly lose leaves at sub-zero temperatures. oak leaves immediately acquire a brown color, along with the leaves, ripe acorns fall from the tree.
Mountain ash in autumn: video
Already in the first days of September, the characteristic signs of the next season are clearly visible on the trees. They are carried by the imminent autumn. Leaf fall for each type of tree occurs at its own time.
Features of leaf fall
Watching the trees, you involuntarily begin to think, and when does the leaf fall of the linden, mountain ash, apple tree and other plants end? Leaf fall is an uneven phenomenon, its duration is estimated at several weeks. Multi-colored foliage is in no hurry to leave the crown. Colorful leaves seem to reluctantly leave the branches one by one.
Abundant fall of foliage occurs at the end of September and the beginning of October (until the first decade expires). Leaves caught by the third and subsequent frosts fall off en masse. Dense leaf fall covers the ground with a motley carpet.
The leaves, flying vertically, gently fall to the ground, covering it with a thick bedding that saves the rhizomes from freezing. Slanting rushing leaves play bright gusty wind, having circled enough, they find a safe haven.
The beginning of leaf fall
The crowns of lindens begin to blaze with autumn colors long before the arrival of the first frost. In the last days of August, single strands are visible among the branches, painted in grayish-yellow tones. The proportion of colored leaves increases daily, the color palette becomes more intense. A noticeable gilding creeps on the crowns of lindens. And after 14-20 days, the foliage begins to burn with gold.
By this time, birches put on an ocher-yellow outfit. Foliage is reddening. Ash crowns shine with pale honey tones. Oak leaves are filled with brown colors. In the lacy crowns of mountain ash, pink leaves shine. And the wild rose bushes flash with a wine-red color scheme.
By the time the leaves of the linden fall, and this happens not earlier than September 23, the crowns of other trees are already actively exposed. The first leaves of birches, aspens, maples and hazel fell off on September 14th. Intense leaf fall in lindens is noted after the first frost piercing the air, which usually happens on September 27th.
First, lindens lose their leaves from large branches located below. Then the foliage crumbles from the middle of the crown. Tops of lindens are exposed last. In elms, ash and hazel, on the contrary, the upper branches are first exposed.
End of leaf fall
By October 7, lindens lose their last leaves. At that moment, when the leaf fall near the linden ends, together with the alder, they did not even think about exposing their dense crowns. Their leaves do not change color, they remain green until the first fluffy snow. Their foliage, seized by a strong frost, instantly turns black. It is difficult for crispy frozen leaves to stay on the branches, they quickly crumble to the ground.
By the time the leaf fall of the linden ends, the elm and bird cherry are completely bare. Their leaf fall ends by September 24th. Aspens are ahead of lindens, their leaf fall comes to an end on October 5th. Birch, maple and hazel are in no hurry to part with foliage. A few leaves are kept on them until October 15.
Natural phenomena during linden leaf fall
The period of leaf fall of lindens is accompanied by the arrival of cold fronts and night frosts. Cumulus clouds displaces a continuous veil and a grayish haze. Flocks of birds flying south appear in the sky. After September 27, the cranes stretch across the sky in a slender shoal in a southerly direction.
And when the leaf fall near the linden ends, the half-naked crowns of other trees blaze with the brightest contrasting colors. Rooks, huddled in friendly flocks, fly away to warmer climes. Snow dust swirls in the air. Falling snowflakes do not yet fall to the ground, do not powder its surface. Puddles twitching thin ice. Skies of dirty grayish shades, devoid of clouds, turn into a gloomy rain film.
Sasha K. (Belogorsk)
In what period does the leaf fall of linden and birch begin and end?
With the onset of September, the trees gradually begin to change the summer emerald green color of the leaves to autumn yellow. A little more time will pass and all the golden foliage will rush to the ground. Watching nature, people often ask themselves the question - when does the leaf fall end for birch, linden, maple and other favorite yellowing trees? Let's try to answer this question.
When the leaves turn yellow
Foliage begins to change color long before the first frost. As a rule, this happens at the end of August, when the day has already noticeably decreased and it has become a little colder, and lasts for 14-20 days. At first, only single gray-yellow patches are visible on the branches, but day by day there are more and more of them.
By mid-September, birch leaves become ocher-gold and gradually begin to fall off. Maple branches are no less beautiful at this time. The crowns of the tree are covered with foliage of yellow, brick red, red and even purple hues. The foliage of the linden, which is only half yellowed, stands out noticeably.
The beginning of leaf fall
For many trees, leaf fall is uneven, that is, it happens at different times. For example, after the first severe frost, leaf fall begins in linden and maples. By this time, the birch had already dropped most of the leaves. Her leaf fall begins in the first decade of September and lasts 15-20 days.
Important! The beginning of leaf fall depends on the weather. Dry sunny weather and windless days delay the golden decoration of trees.
Leaf fall is especially abundant after the third frost. The leaves fall to the ground very densely, forming a thick bedding on the ground. Birch drops about 30 kg of leaves in autumn. In an adult linden and maple, this amount reaches 40-50 kg.
End of leaf fall
The end of leaf fall, as a rule, is accompanied by a significant cooling, worsening weather conditions, frequent rains and strong gusts of wind. By October 7-10, lindens and birches lose their last yellow leaves. Maples are exposed much later, only by October 20. Single leaves can be kept on the branches until mid-November, reminding passers-by of the past golden season.
Observations of nature during leaf fall
The period of active leaf fall is accompanied by a significant cooling and the arrival of night frosts. Summer white clouds are replaced by a solid gray veil. It is often foggy in the morning. The first flocks of migratory birds fly into the sky.
The end of leaf fall in lindens and maples is accompanied by gloomy rainy weather, frost on the still green grass and thin ice on the puddles. Rooks gather in flocks and fly south. Gradually the earth cools down and nature falls asleep.
Autumn leaf fall: video
