Yesterday, while walking in the park, for some reason I thought for the first time. Why are the leaves multi-colored and this is what I found on the Internet: Plant leaves are colored green because they contain chlorophyll, a pigment that is present in plant cells. A pigment is any substance that absorbs visible light. Chlorophyll absorbs sunlight and uses its energy to synthesize nutrients.
But in autumn, plant leaves lose their bright green color.
For example, poplar leaves turn golden, while maple leaves seem to flash red. Some chemical transformations begin in the leaves, that is, something happens to chlorophyll. With the arrival of autumn, plants prepare for winter. Nutrients slowly move from the leaves to the branches, trunk, and roots and are stored there during severe cold weather. When spring arrives, plants use stored energy to grow new green leaves.
When the energy of stored nutrients is depleted, chlorophyll synthesis stops. The chlorophyll remaining in the leaves partially disintegrates, and pigments of a different color are formed. Yellow and orange pigments appear in the leaves of some plants. These pigments consist mostly of carotenes, the substances that give carrots their orange color. For example, the leaves of birch and hazel become bright yellow as chlorophyll disintegrates; the leaves of some other trees acquire various shades of red.
The red, dark cherry and purple hues of some leaves are due to the formation of anthocyanin pigment. This pigment colors radishes, red cabbage, roses and geraniums. Under the influence of autumn cold, chemical reactions begin in the leaves, converting chlorophyll into red-yellow compounds. Unlike carotenes and other yellow pigments, anthocyanin is generally absent in green leaves. It is formed in them only under the influence of cold. The color of autumn leaves, like the color of human hair, is determined genetically in each plant species. But whether this color will be dull or bright depends on the weather.
The brightest, richest colors of the leaves occur in autumn, when cold, dry and sunny weather lasts for a long time (at temperatures from 0 to 7 degrees Celsius, the formation of anthocyanin increases). There are beautiful fall leaf colors in places like Vermont. But, for example, in Great Britain, where the climate is rainy and the weather is cloudy almost all the time, autumn leaves are most often dull yellow or brown.
Autumn passes, winter comes. Along with the leaves, the plants also lose their colorful colors. The leaves are attached to the branches by special cuttings. With the onset of winter cold, the connection between the cells that make up the cuttings disintegrates. After this, the leaves remain connected to the branch only by thin vessels through which water and nutrients enter the leaves. A slight breath of wind or a drop of rain can break this ephemeral connection, and the leaves will fall to the ground, adding another touch of color to the multi-colored thick carpet of fallen leaves.
Plants store food for winter, like chipmunks and squirrels, but they accumulate it not in the ground, but in branches, trunks and roots.
The leaves, into which water stops flowing, dry out, fall from the trees and, caught by the wind, circle in the air for a long time until they settle on the forest paths, lining them with a crisp path. The yellow or red coloration of the leaves may persist for several weeks after they have fallen. But over time, the corresponding pigments are destroyed. The only thing that remains is tannin (yes, this is what colors the tea). In autumn, when the leaves become isolated from the branches of the tree and no longer receive water and minerals, photosynthesis stops. When the leaves are isolated, the nutrition-producing chlorophyll that gives the leaves their green color is destroyed, and other colors begin to appear - they were present in the leaves all along, but due to the abundance of green chlorophyll, they were not visible. Yellow and orange colors appear - this is a tribute to the pigment carotene, thanks to which, by the way, carrots have their orange color.
The beautiful colors of fall are also the work of pigments, which are created by chemical reactions caused by the unique combination of weather conditions in autumn: cooler temperatures at night and shorter days promote the formation of anthrocyanin, the pigment that gives leaves their red and purple hues. Autumn temperatures produce red colors that result from a reaction with glucose, the sugar left in the leaves after photosynthesis has stopped.
The brightness of the colors of autumn leaves and the time during which we can admire them before the leaves fall depend on changes in the weather. When temperatures are low (but below freezing), more anthrocyanine is produced, which gives the leaves their bright red color. The brighter colors of autumn can also be a result of gloomy and rainy days.
Every year in mid-autumn we all observe a beautiful color spectacle of falling leaves, but hardly anyone thinks about why this happens and what it is connected with. Leaves that turn rusty in autumn can be said to be a food plant nature. Plants obtain water from the soil through their roots, and their leaves absorb carbon dioxide from the air. With the help of sunlight, water and carbon dioxide are converted into glucose. It stimulates the growth and development of greenery.
The process of converting water into glucose using sunlight is called photosynthesis. A chemical called chlorophyll contributes to this process. It is what gives plants their green color.
By the end of summer - beginning of autumn, the days become shorter. Thus, the trees sense the approaching cold and begin to prepare for winter.
In cool weather, the amount of water and sunlight is insufficient to facilitate photosynthesis. At this time, the trees begin to feed on the food they accumulated during the summer. The so-called green plant is closed, a lack of chlorophyll is gradually causing the leaves to lose color and take on the rusty hue of autumn. Depending on the temperature and humidity of the weather, the leaves will lose their green color faster, and if there is a sudden early frost, they will fall off faster.
Maple leaves, for example, retain significant amounts of glucose in their composition, even after photosynthesis has completed. Thus, cold nights and those few rays of sun that manage to deceive the clouds and nourish the leaves are the main ingredient in trees whose leaves are colored bright red.
Oak leaves turn brown in the fall because they store not only glucose, but also waste.
Trees and plants prepare for winter, and give us the opportunity to admire their beautiful colors every time.
Chlorophyll is a real food production unit that is found in every leaf. Two-thirds of the leaves depend on the presence of chlorophyll. Each leaf has other shades, but due to the dominant one, they are almost invisible. But they still exist. "Xanthophyll" - has a yellow color. It consists of oxygen, hydrogen and carbon and occupies 23% of the pigmentation of the entire leaf. Another shade is given by carotene and it accounts for 10% of the total pigmentation.
Anthocyanin gives leaves bright red shades. From early spring until autumn, only green chlorophyll is visible to us. But when autumn begins, nutrients enter only the trunk and branches of trees, because nutrients cease to be produced, and the existing chlorophyll decomposes. When it completely disappears or its content in the foliage decreases significantly, this is where other pigments that are constantly present in the leaf appear. That's when the variety of colors on the trees begins.
Before a leaf falls from a tree, a thin layer of cells forms at its base, which indicates the location of that leaf.
But today there is another theory about trees shedding their leaves as winter approaches. It was put forward by British scientist Brian Ford. The theory was proposed for discussion in The Daily Telegraph. He believes that trees shed their leaves for the same reason that a person does when going to the toilet. Wanting to get rid of excess substances accumulated inside, the tree gets rid of its foliage. For a long time, the leaf was perceived as an energy storage organ, but the same leaf also removes all unwanted substances from the tree. Before shedding, the level of harmful components of tannin, oxolate, and heavy metals in the leaves increases. Hence the conclusion follows that the tree would rather be freed from harmful substances than left for storage for the winter. The proposed hypothesis cannot prevent you from admiring the autumn colors.
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What is the fall outfit like?
There is little sunlight and heat for plants, and the green color of the leaves gives way to yellow, orange, blue-violet. Of the trees, only rowan, aspen and maple have red autumn leaves. Alder and many willows remain green until the leaves fall. All other trees have leaves that turn yellow, but in different ways: bright yellow leaves on birch, darker yellow on elm, yellow-brown on oak, golden yellow on linden.
From a distance, the foliage of the tree seems all the same color, but if you pick up a leaf - what color is there!
Green stripes and brown spots, burgundy patterns and varied transitions of different color shades.
Some leaves look like the finest lace. The trees and shrubs were brightly, colorfully, and colorfully dressed. A real carnival of colors!
It would seem, why should trees shed such a magnificent outfit? They would stand and stand until spring with leaves. It is forbidden. If it falls and snow sticks to the foliage, the branches of the trees will not withstand its weight and will break off. Sometimes such a misfortune happens if snow falls much ahead of time. So the trees shed all their leaves.
In addition, the tree prudently removes all unnecessary substances into the foliage. Then, like a cork, the leaf petiole is plugged with dead cells. And with the first gust of wind, the leaves break off and fall.
The earliest trees to lose their leaves are linden, birch and elm. Already at the end of early autumn, leaf fall began for them. In some trees, for example, linden and poplar, the leaves of the large lower branches fall off first, the middle gradually becomes exposed, and the top of the tree flies last. But in elm, hazel, and ash, leaf fall begins from the upper branches. The foliage gradually melts, revealing the dark trunk of the tree.
With the first frosts, aspen leaves fall off, followed by maple leaves. Only alder and willows along the banks of the rivers stand thick and green until the first snow. And then the frozen, blackened, crispy leaves fall to the ground.
The tips of the larch needles began to turn yellow. In golden autumn, the needles will turn bright yellow, glowing against the sky.
Only the spruce and pine stand green, with their dark silhouettes enhancing the brightness and sonority of the autumn colors. Their leaves - needles - are not afraid of frost. Each needle, like a fur coat, was covered with a waxy coating.
It makes a significant contribution to the economy.
Coevolutionary
Climate impacts
According to those given in the magazine Global Change Biology According to research, climate change is delaying autumn leaf coloring but increasing forest productivity.
The leaves of many plants are characterized by a different color change: young leaves are red or purple in color, and become green later. This phenomenon is typical, for example, for red elderberry ( Sambucus racemosa) and Pieris japonica ( Pieris japonica). This phenomenon is associated with an increased content of anthocyanins in young leaves; these pigments have the property of converting light energy into heat, which is important for the development of the plant in early spring.
see also
Notes
Links
Wikimedia Foundation. 2010.
See what “Colors of autumn leaves” are in other dictionaries:
Keracyanin rutinosyl 3 cyanidin, an anthocyanin found in the drupes of cherries (Cerasus). Anthocyanins (from the Greek ἄνθος flower and κυανός blue, azure) colored plant glycosides containing as an aglycone ... Wikipedia
Anthocyanins give the purple color to these pansies Anthocyanins (from the Greek ἄνθος flower and κυανός blue, azure) are natural substances, coloring substances of plants, from the group of flavonoids; belong to glycosides. Contents 1 The structure of molecules ... Wikipedia
This term has other meanings, see Leaf fall (meanings). G. G. Myasoedov. Autumn morning. 1893 ... Wikipedia
For the term leaf fall, see other meanings. Fallen leaves... Wikipedia
I MAP OF THE JAPANESE EMPIRE. Contents: I. Physical essay. 1. Composition, space, coastline. 2. Orography. 3. Hydrography. 4. Climate. 5. Vegetation. 6. Fauna. II. Population. 1. Statistics. 2. Anthropology. III. Economic essay. 1 … Encyclopedic Dictionary F.A. Brockhaus and I.A. Ephron
Color- Adjectives WHITE/LY, aleba/stroy, whitish, squirrel/foamy, snow-white, limestone, ki/foamy, lily/y, flax/th, chalky/th, milky, sugary, gray /th, silvery, snowy. The lightest color in existence, the color... ... Dictionary of Russian synonyms
Autumn is a bright period in nature, when the forest changes the color of its leaves from green to yellow, red and brown in a matter of days.
What explains the riot of colors during the leaf viewing season? Why do some trees turn yellow, others turn red, and then they turn brown.
The explanation lies in the replacement of chlorophyll with other substances: carotenoids and anthocyanins. In summer, trees have a lot of nutrients, but with the arrival of autumn, this supply gradually decreases. With the depletion of reserves, the synthesis of chlorophyll stops. And then other pigments that are present in the leaves, but overlapped by the green color - yellow and orange - become noticeable. These are the same pigments that determine, for example, the color of carrots - carotenoids.
Leaves with red hues are the result of the formation of anthocyanins. These pigments are absent in green leaves. They begin to form in the leaves of some plant species after the disappearance of chlorophyll. Anthocyanins are the same pigments that give radishes, geraniums, roses or cauliflower their color.
The brightness of the color of autumn leaves depends on the weather. Trees wear their most beautiful clothes in sunny, dry weather, at a temperature of 0 - 7 degrees Celsius. If the weather is cloudy and rainy, then the leaves do not burn, but turn into dull yellow shades or even turn brown.
As winter approaches, yellow and red leaves gradually lose their pigments. Brown leaves, which can be seen in late autumn, with the onset of severe cold, after snowfall, are leaves in which there are no pigments left at all, and the cell walls have become noticeable.
What color are the leaves of trees in autumn?
Birch leaves are yellow-golden in autumn
Maple leaves are red in autumn
Alla Salamatina
Program content: Clarify children's knowledge about autumn. Introduce children to the concepts of trees. Learn to show and name what parts a tree is divided into (roots, trunk, branches, leaves, what they are needed for, what role they play in the life of trees. Explain that trees need our care, tell what trees are afraid of. Learn to admire the beauty of autumn nature. Draw children's attention to the distinctive features of different types of trees (color of bark, shape of leaves). Develop observation, attention, speech, memory, fine motor skills. Cultivate a caring attitude and love for nature.
Dictionary. Concept words - birch, maple, rowan, oak, linden, poplar, aspen. Words signs - cloudy, longer, shorter, colder, yellow, red, green, brown, orange, large, small, medium, birch - birch, oak - oak, maple - maple, and so on Glory of action - turn yellow, grow, blow , drizzling.
Integration of areas. Cognition, health, socialization, communication, safety, reading fiction, music.
Equipment.
Demonstration material – Pictures of trees and shrubs, presentation “Autumn. Trees", a bouquet of autumn leaves.
Handouts – D/I “Which tree is the leaf from”, “Select by color”, maple, oak, birch leaves, colored pencils, red and yellow circles, 5 pieces each.
Technical teaching aids – Laptop, wireless computer mouse, projector, screen.
Progress of the lesson
Organizing time. Find your place, D/I “Select by color”
There are leaves of different trees of different colors on the floor. They suggest finding your place at the table by the color of the leaf. For example: a child has a red maple leaf, and there is a red aspen leaf on the table.
Autumn has come to visit us,
Made a mess
I scattered all the leaves,
We'll collect them first.
We will find our place
Let's sit quietly at the table.
To find your place, you need to find a piece of paper at the table of the same color as you picked up from the floor.
After which the teacher clarifies what color the child’s leaf was and what tree it came from, and what leaf is on the table. Thus, it clarifies children’s knowledge about trees.
Slide 1. Conversation about autumn.
The teacher asks the children questions.
What time of year is it now?
Why did you decide that it’s autumn outside?
What signs of autumn do you know?
Slide 2.
Watching the video clip “Autumn in the Forest” by I. V. Yankov
Let's see what happens to nature in autumn.
Slide 3.
What types of trees and their parts are there?
In autumn, the leaves on the trees change color and fly off, and what trees do you know?
How are trees different from each other?
What do all trees have in common?
Let's look together at what parts does a tree consist of? On slide 3, the teacher and the children clarify the names of the parts of the trees.
Trunk - Every tree has a trunk, through which nutrients rise from the roots to the branches and leaves. As a rule, a tree has one trunk.
Branches – there are many branches on the trunk, they are thinner and more flexible.
Leaves – Every tree has many leaves that help purify the air. The tree breathes leaves.
Roots - all plants have roots, a tree has thick roots, they are needed for the tree to stand firmly and not fall, and through the roots all plants feed, they take food from the ground and along the trunk it goes to the branches, and then to the leaves . That's why the tree grows. It is alive, just like you and me. The tree eats, breathes, grows.
Slide 4.
Now let's remember what parts a tree consists of.
Slide 5.
Looking at leaves in an autumn bouquet.
Today, when I was going to kindergarten, I met Lesovich, and he gave us a beautiful bouquet of autumn leaves. Let's look at which trees these leaves come from. A teacher and children examine leaves in a bouquet.
Finger game “Bouquet for Mom”
One, two, three, four, five I bend my fingers while counting.
We will collect leaves. They clench and unclench their fists.
Birch leaf, rowan leaf, Bend your fingers when listing.
Maple leaf, aspen leaf,
Let's collect oak leaves,
We'll take a beautiful bouquet to mom. Wrists are closed, palms
Mommy's favorite. Disconnected, fingers to the sides.
Slide 6.
Let us look at the leaves of the trees again, because many are very similar to each other. The leaves of poplar and birch are very similar to each other, but how do they differ, let's see.
Slide 7.
Maple leaves look like crow's feet, and aspen leaves are round like apples.
Slide 8.
Rowan leaves are small, oval and collected on a branch. And an oak leaf looks like a small tree.
D/I “Which tree is the leaf from”
We've looked at the leaves, now let's play.
The angry wind came running,
I scattered all the leaves.
We will bring them together
And we’ll put it near the tree.
The teacher invites the children to collect leaves and find pictures of the trees on which they grew.
"Find and Circle"
Let's draw a bouquet of autumn leaves for our mothers. Find a maple leaf and circle it in orange. Circle the birch leaf on the right on the right, and the oak leaf on the left in green.
Slide 9, 10.
Visual gymnastics. Children are asked to follow the movement of leaves on the screen with their eyes.
Collect beads.
Autumn loves to dress up in beautiful outfits. Let us collect beads for her from red and yellow circles. The circles must be alternated one at a time. One red, one yellow, again one red and one yellow. Collect beads for fall.
Summary of the lesson. We played a lot today, but what new did you learn today? What did you like?
I suggest you today play new games on the street, collect leaves from different trees and put them in books to dry, and then you and I will make very amazing things from them. Want to? Then don't forget to collect the leaves and dry them.