Why are coniferous trees green all year round? Which coniferous tree sheds its needles in the fall? Why does pine turn yellow in summer?
This is exactly larch. It’s nickname is that in the fall it sheds its needles like leaves. In the spring, it again dresses in its leaves (needles). An amazing tree. Young needles are not light, but during the summer they acquire a darker shade.
I was recently on an excursion, and they were talking about larch, which turns yellow in the fall and sheds its needles. And in the spring, new, green ones appear. So a coniferous tree that sheds its needles in the fall is larch.
In my opinion, the larch stands bare in the winter) and in the spring new green needles begin to emerge. And besides, they are delicious)))) so sour.
The pine family includes not only our beloved pine. The pine family includes larch, a tree with needles instead of leaves. They gave larch this name because a tree with needles sheds its needles, like a birch tree, like aspen, poplar, maple and any other deciduous tree. So we answer that the larch remains without needles in the fall. But the larch remains without needles in the second year of its life; in the first year, the larch overwinters with needles. Scientists believe that this is how adaptation to harsh climate occurs.
Different types of larches shed their needles at different times. Observations show that Siberian larch remains without needles by the end of October, American larch remains without needles in November.
Indeed, not all trees that are commonly called conifers are evergreen. The most well-known coniferous tree that sheds its leaves (in this case, needles) in the fall is larch. Pseudolarches, Taxodium, Metasevoy and Glyptostrobus also shed needles.
Mostly coniferous plants are evergreen, that is, leaves, needles, and needles remain on the plant for several years (from 2 to 40). but there are 5 genera of coniferous plants that, having shed their leaves - needles, overwinter naked, these are larch, pseudo-larch, glyptostrobus, metasequoia and taxodium.
Only larch of the coniferous trees sheds its needles for the winter, since the other trees: fir, spruce, cedar and pine overwinter with needles and are therefore called evergreen.
Larch forests are very common in Russia and this tree is the main one in the construction of wooden houses, since larch wood is heavily impregnated with resin and is therefore difficult to rot.
Despite their fellow conifers larch sheds its needles every autumn. A beautiful tree, the needles are not soft, fluffy, not prickly at all, and the wood is considered one of the strongest. It should be noted that all conifers renew their needles anyway - old ones fall, new ones grow, but this happens throughout the year and they remain green all year.
This tree is called larch. Like deciduous trees, it sheds its needles in the fall, just like trees shed their leaves. First, the needles on the larch turn yellow. and then it starts to fall off. This is how the tree renews itself and begins to grow stronger in the spring.
It is believed that larch is the only coniferous tree that gets rid of the thorns that have grown over the summer during the winter. Larch developed this unique mechanism for conifers as an adaptation to the sharply cold climate. Larch is a very beautiful tree with valuable wood. There are several species, the easternmost of which, Kaempfer's larch, lives in Japan.
However, there are also coniferous trees that can shed their needles for the winter - these are metasequoia and swamp cypress, both trees of the cypress family. Both plants live in America and the appearance of their needles bears little resemblance to the coniferous trees we are used to.
Many coniferous trees remain green and lush all year round.
But not all conifers are evergreen. Among them there are those that shed their needles for the winter.
These include:
HOW MANY YEARS DOES THE HVOINKA LIVE?
We are used to seeing our coniferous trees always green - both in summer and winter. Only larch behaves differently. The crowns of larches turn yellow in the fall, and then all the needles fall off. But spruce, pine, and fir retain their green attire all year round. And not only all year round, but throughout life - from very early age to old age. And this sometimes takes many decades.
It is clear, of course, that individual needles live not for decades, but much less. Their lifespan is much shorter than the life of an entire tree. Until the same pine or spruce reaches old age, they will be replaced by many generations of needles. But this change occurs gradually and is not noticeable. Some needles fall off, others grow back. However, the tree remains green all the time. Renewing needles does not affect the appearance in any way.
How long does an individual needle live? How long is her life expectancy? Few people have probably thought about this question. The age of the needle varies among different tree species. Here, as in many other things regarding plants, there is no uniformity. In some trees, the needles live for a shorter period, in others for a longer period.
What is the situation with our most common evergreen conifers? Let's take the common pine tree, for example. Individual needles of this tree live relatively short lives - usually only 2-3 years. They are always collected in pairs and also fall together, connected to each other. These twins can be seen on the ground under a tree at any time of the year. It is not difficult to determine the lifespan of a pair of needles. To do this, you need to look at a pine branch from close range. And best of all, on the branch of a young, still short tree. On such a branch, one can easily distinguish the growth of the last year - the youngest section of the stem, located closest to the end. It is completely covered with bright green needles. Next comes the next section of the stem - the growth of the previous year. It also bears green needles. But the third segment, that is, the growth of an even earlier year, is almost devoid of needles. There are few of them there and they are often not green, but yellowish, dying. The growth of the fourth year is completely bare. Pine needles are preserved only on growths no more than three years old. To determine the lifespan of needles, it is important to be able to distinguish the boundary between the growth of individual years. This border is usually visible on the branches quite clearly.
Now about the food. Its needles are located singly and live much longer than those of pine, usually 5-7 years. Their lifespan can be determined in the same way as that of pine, by the number of annual growths of the stem covered with living needles.
As for fir, it is distinguished by a particularly long life of its needles - up to 12 years. This tree is similar in appearance to spruce and has a thick, dense crown that greatly shades the soil. But the cones are not at all like those of spruce, but thick, shaped like a barrel. Moreover, they do not hang down, but, on the contrary, are directed upward (like candles on a Christmas tree). It is different from that of spruce, and the bark on the trunk is smooth, not scaly. The needles are also different - soft, not prickly.
It is interesting that for the same tree species, the lifespan of needles varies depending on the soil and climatic conditions in which the tree grows. In more severe conditions, the life of needles is significantly extended. So, if pine needles in the middle zone of the country usually live 2-3 years, then in the Far North this period increases to 5-7 years. A similar phenomenon is observed in spruce and fir. The lifespan of the needles of these trees in unfavorable conditions is also extended.
It should also be said about the time of falling off of dead old needles. Pine is especially noteworthy in this regard. It sheds old needles in early autumn, over a fairly short period. Before this, at the end of summer, the needles on older parts of the branches become orange-yellow and are clearly visible in the crown of the tree among the green living needles. Then they fall off quite nicely. In terms of the timing of needle drop, pine is somewhat similar to our deciduous trees. The massive fall of yellowed pine needles is especially noticeable where the soil surface in the forest is covered with a green carpet of mosses. At the end of autumn, this carpet is completely covered with many needles that have just fallen from the trees.
The situation is completely different for spruce and fir. The dry needles of these trees fall off more or less gradually, unevenly, throughout almost the entire year. And they are not painted in bright orange-yellow tones, but have a more modest brownish color.
As you know, pine and spruce leaves do not fall in the fall. Why are conifers evergreen trees?
All trees feed on leaves. Their surface absorbs sunlight, and water flows from the roots through numerous channels. A special green substance that is found in all leaves - chlorophyll- converts these two components into food for the tree. In this case it would O Most of the water evaporates from their wide surface. With the onset of cold weather, deciduous trees receive less sunlight and water from frozen soil. To survive the winter, they store the necessary amount of nutrients and moisture, shed their leaves and hibernate. Their trunk and branches are reliably protected from frost by bark.
Pine and spruce leaves - needles- These are thin needles covered with a thick sheath. Thanks to this, they almost do not lose moisture from the surface and can remain on the tree during the cold season. They also accumulate a small amount of water and sugars to nourish the tree in winter, as well as oils that prevent the needles from freezing in frost. Pine and spruce needles fall off, but this happens gradually, and new ones immediately grow in their place.
Therefore, conifers are evergreen trees.
The famous Russian poet Fyodor Ivanovich Tyutchev wrote a poem about this:
Let the pines and spruce
They hang around all winter,
In snow and blizzards
Wrapping themselves up, they sleep, -
Their skinny greens,
Like hedgehog needles
At least it never turns yellow,
But it’s never fresh.
The tradition of an evergreen spruce or pine appearing as a New Year's guest
Did you know that in ancient times our Slavic ancestors celebrated the New Year with cherry blossoms? Shortly before the holiday, the tub in which the tree grew was brought into the house. In the warmth, buds developed, and the tree was densely covered with a delicate white-pink color.
People were having fun around the New Year's cherry tree - they danced in circles and sang songs. The flowering tree remained in the house until spring. Then it was planted in the warmed spring soil.
Later, the evergreen Christmas tree replaced the whitening cherry tree. In our area, the New Year tree holiday was introduced by a special decree of Tsar Peter the Great in the year one thousand seven hundred. The decree pleased both the nobility and the common people. Since then, our usual beautiful tradition of decorating the Christmas tree before celebrating the New Year has appeared.
Home -> Encyclopedia ->Why don’t the leaves (needles) of pine and fir trees fall off in winter like those of other trees?
Please answer in more detail! Thank you!
Coniferous trees have to withstand very harsh winters. The temperature there is below 0°C, and often drops below - 40°C. Winters bring severe drought as the groundwater freezes completely. The snow lies for a very long time, only a thin layer of soil thaws in the summer, and there is little water available to plants.
Conifers are evergreen so they can continue to produce nutrients. The surface area of one needle (their “leaf”) is very small, and it is also covered with a layer of wax. This delays evaporation and helps conserve water. In addition, the needles produce a substance that prevents them from freezing and dying from frost.
In winter, conifers make the most of sunlight. Their shape is such that the sun's rays reach every tree. The heat reflected by the snow is trapped between the trees.
As you know, in nature there are deciduous and coniferous trees. Deciduous trees are also called deciduous trees, because. Every autumn they shed their yellowed leaves. Coniferous trees, for the most part, remain green all year round. And the most beautiful coniferous tree is undoubtedly spruce. There are about 50 species of spruce; it is common in Europe, Northeast and Central Asia, North America, and China. And everywhere it pleases the eye with its grace, majesty and evergreen decoration. So why is spruce the same color in winter and summer?
To answer this question, first a few words must be said about deciduous trees. Leaf fall, as is known, is a natural adaptation for the life of deciduous trees in winter conditions. Leaf fall saves trees from loss of moisture and drying out in the winter cold, and also protects branches from injuries and fractures under the pressure of a large mass of snow. And coniferous trees, especially spruce and pine, tolerate drought well. They are called drought-resistant. They tolerate the winter season well, when it is difficult to obtain water from frozen soil. And the amount of evaporated moisture in spruces and pines is many times less than in deciduous trees. And all because they have a drought-resistant device that allows them to save moisture accumulated over the summer - pine needles.
Thin needles of coniferous trees are modified leaves. In them, just like in ordinary leaves, the processes of photosynthesis occur, life-giving juices are exchanged through them and they also evaporate moisture, but very little. This is due to the fact that the surface of pine needles is much smaller than that of leaves; moreover, they have a thick skin and are covered with a shiny waxy coating that reflects sunlight, which contributes to less evaporation of moisture. And finally, the stomata in conifer needles are located in special recesses, which also reduces the amount of evaporated moisture.
These drought-resistant adaptations allow spruce and other conifers to remain green all year round rather than shed their leaves in the fall. In addition, spruce branches have a pyramidal shape, they are strong, wide, and spreading. They are not afraid of snow and blizzards, they will not break under a large mass of snow. This is another reason why spruce does not shed its needles in the fall, but remains evergreen.
And since these trees retain their green attire all year round, they are always ready for photosynthesis. Therefore, it is coniferous trees and shrubs - spruce, pine, fir, cedar, thuja, juniper - that enrich the air with oxygen in winter, clean it and fill it with phytoncides, which are natural antiseptics. That’s why it’s so easy to breathe in a coniferous forest. True, many spruces do not take root well in big cities because they do not tolerate polluted air well. And the most unpretentious is the blue spruce - which is why it can be seen so often in the alleys of our city parks and squares.
Do not think that spruce never changes its green outfit. It changes, but not overnight, but gradually. Anyone who has been to a coniferous forest has probably seen a lot of fallen needles, but no one has seen completely bare pines and spruces. The fact is that in the spring the fallen needles are replaced by young, grown needles. Pines retain their needles for two to three years, and spruces wear their plumage for five to seven years. And to completely renew its needles, spruce trees need about nine years.