The world around provides all living things with the opportunity to exist in harmony with nature, although its pristine nature is somewhat disturbed. But to this day, green trees produce the oxygen necessary for respiration. The planet has provided humanity with the opportunity to improve themselves, taking care in advance of ways to meet its biological needs.
Why are trees green
The color of any object we perceive through the rays reflected by it. The leaves, absorbing the red and blue part of the spectrum (according to the Maxwell additive triad (MGB - red, green, blue)), reflect green.
Chlorophyll is present in leaf cells, a complex chemical dye that is similar in its mechanism of action to hemoglobin. In any tiny cell of the leaf, there are chloroplasts (chlorophyll grains) in an amount of 25 to 30. It is here, in them, that the most important action of the planetary scale takes place - the conversion of solar energy. Chloroplasts convert it to glucose and oxygen using water and carbon dioxide.
The Russian scientist K. A. Timiryazev was the first in the world to explain this phenomenon (the conversion of solar energy into chemical). It is this discovery that shows the main role of plants in the origin and continuation of life on the planet.
Photosynthesis
The leaves of green trees work as a continuously working plant for the production of glucose (grape sugar) and oxygen. Under the influence of sunlight and heat in the chloroplasts, photosynthesis reactions between carbon dioxide and water. From a water molecule, oxygen is produced (released to the atmosphere) and hydrogen (reacts with carbon dioxide and is converted to glucose). This photosynthesis reaction was experimentally confirmed only in 1941 by the Soviet scientist A.P. Vinogradov.
C₆H₁₂O₆ is a glucose formula. In other words, it is a molecule that enables life to continue. It consists of only six carbon atoms, twelve hydrogen and six oxygen. In the reaction of photosynthesis, upon receipt of one glucose molecule and six oxygen molecules, six molecules of water and carbon dioxide are involved. In other words, when green trees produce one gram of glucose, a little more than one gram of oxygen gets into the atmosphere - this is almost 900 centimeters cubic (about a liter).
How long does the leaf live?
The main source of renewable oxygen reserves are green trees with their huge mass of leaves.
Nature, depending on climatic zones, divided the plants into deciduous and evergreen.
Deciduous trees retain their foliage from spring to autumn - this period is favorable for tissue growth and photosynthesis processes that the plant itself needs for further growth. Such a short leaf life, scientists believe, is due to the high intensity of the processes that take place in them, and the non-renewability of tissues. Such trees include oak, and birch, and linden - in a word, all the main representatives of both urban and forest vegetation.
Evergreens retain their foliage (often modified forms) for longer periods - from five to twenty (on some trees) years. That is, in fact, these green trees also have leaf fall, but much less intense and stretched over time.
The life processes of trees
In mixed spring forests, the difference in the moments of awakening of trees is clearly noticeable. Deciduous plants begin to dissolve buds, turn green, very quickly gain mass of leaves. Conifers (evergreens) wake up somewhat more slowly and less noticeably: first the density of the color changes, and then the buds with new shoots open.
The beginning of a new life is most noticeable in the spring forest with its incessant bird's hubbub, the murmur of meltwater and the intense croaking of frogs.
With the thawing of the soil, the plant begins to absorb the root mass of water and feed it into the stem and branches. The height of some trees can reach one hundred meters. In this regard, the question arises: "How can a plant raise water with nutrients to such a height?"
Normal pressure in one atmosphere helps to raise water to a height of ten meters, but what is higher? Plants adapted to this by creating a special system for raising water, consisting of vessels and tracheids in the wood. It is through them that the transpiration current of water with nutrients is carried up. The movement is due to the evaporation of water vapor into the atmosphere by a sheet. The rate of water rise in the transpiration system can reach one hundred meters per hour. The rise to a great height is also provided by the cohesive force of water molecules, freed from the gases dissolved in it. To overcome such a force, you need to create tremendous pressure - almost thirty to forty atmospheres. Such force is enough to not only raise, but also to keep the pressure of water at a height of up to one hundred and forty meters.
According to another system, consisting of sieve tubes in the bast (in the subcortex), green trees circulate the organic substances produced by the leaves.
Evergreen trees: what forms of leaves nature has created
The climatic zones of our planet are diverse, their humidity and temperature differences made it possible to develop evergreens with their own characteristics.
In areas with an unfavorable winter climate, evergreens are represented by coniferous tree species: pine, spruce, juniper. Their needles are able to withstand a prolonged decrease in temperature to minus fifty degrees.
Evergreens of the tropics and subtropics are represented by both coniferous and deciduous specimens. Deciduous have a dense structure, very often a glossy outer surface. Magnolias, tangerine trees, laurels, eucalyptus trees, cork and paper trees - this is only a small fraction of all kinds of representatives of deciduous evergreen plants. Tui, yews, cedars are representatives of conifers in a hot climate.
As mentioned above, these trees are called evergreen because they do not drop foliage all year round, but their green mass changes constantly and photosynthesis is present in their chloroplasts depending on the state of the tree in winter.