The surrounding world provides all living things with the opportunity to exist in harmony with nature, although its originality is somewhat disturbed. But to this day, green trees produce the oxygen necessary for breathing. The planet has provided humanity with the opportunity to improve itself, taking care of ways to meet its biological needs in advance.
Why trees are green
We perceive the color of any object through the rays reflected by it. Leaves, absorbing the red and blue parts of the spectrum (according to Maxwell's additive triad (MGB - red, green, blue)), reflect green.
Chlorophyll is present in leaf cells - a chemically complex dye, similar in mechanism of action to hemoglobin. In any tiny cell of a leaf, there are chloroplasts (chlorophyll grains) in an amount of 25 to 30. It is here, in them, that the most important action on a planetary scale takes place - the transformation of the energy of the Sun. Chloroplasts convert it into glucose and oxygen using water and carbon dioxide.
Russian scientist K. A. Timiryazev was the first in the world to explain this phenomenon (the conversion of solar energy intochemical). It is this discovery that shows the main role of plants in the origin and continuation of life on the planet.
Photosynthesis
Green tree leaves work like a continuously operating plant to produce glucose (grape sugar) and oxygen. Under the action of sunlight and heat, photosynthesis reactions between carbon dioxide and water proceed in chloroplasts. From a water molecule, oxygen is obtained (released into the atmosphere) and hydrogen (reacts with carbon dioxide and is converted into glucose). This photosynthesis reaction was experimentally confirmed only in 1941 by the Soviet scientist A. P. Vinogradov.
C₆H₁₂O₆ is the formula for glucose. In other words, it is a molecule that makes it possible to continue life. It consists of only six carbon atoms, twelve hydrogen and six oxygen. In the photosynthesis reaction, when one molecule of glucose and six molecules of oxygen are obtained, 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 enters the atmosphere - that's almost 900 centimeters cubic (about a liter).
How long does a leaf live
Green trees with their huge mass of leaves are the main source of renewable oxygen reserves.
Nature, depending on climatic zones, divided plants into deciduous and evergreen.
Deciduous retain their foliage from spring to autumn - this period is favorable for tissue growthand the processes of photosynthesis needed by the plant itself for further growth. Such a short life of leaves, as scientists believe, is due to the high intensity of the processes occurring in them and the non-renewability of tissues. These trees include oak, birch, and linden - in a word, all the main representatives of both urban and forest vegetation.
Evergreens retain their foliage (more often these are 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.
Life processes of trees
In mixed spring forests, the difference in the moments of awakening of trees is clearly visible. Deciduous plants begin to bud, turn green, very quickly gain a lot of leaves. Conifers (evergreens) wake up somewhat more slowly and less noticeably: first, the color density changes, and then the buds open with new shoots.
The beginning of a new life is most noticeable in the spring forest with its incessant chirping of birds, the murmur of melt water and the intense croaking of frogs.
With the thawing of the soil, the plant begins to absorb water by the root mass and supply it to the stem and branches. Some trees can be up to 100 meters tall. In this regard, the question arises: “How can a plant raise water with nutrients to such a height?”
Normal pressure of one atmosphere helps to raise water to a height of ten meters, but howhigher? Plants have adapted to this by creating a special water-lifting system consisting of vessels and tracheids in wood. It is through them that the transpiration flow of water with nutrients upwards is carried out. The movement is due to the evaporation of water vapor into the atmosphere by the leaf. The rate of water rise in the transpiration system can reach one hundred meters per hour. Rise to a great height is also provided by the adhesion force of water molecules, freed from the gases dissolved in it. To overcome such a force, you need to create a huge pressure - almost thirty to forty atmospheres. Such a force is enough to not only lift, but also keep the pressure of water at a height of up to one hundred and forty meters.
Green trees circulate organic matter produced by their leaves through a different system, consisting of sieve tubes in the bast (under the bark).
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 for the development of evergreens with their own characteristics.
In areas with an unfavorable winter climate, evergreens are represented by coniferous trees: pines, firs, junipers. Their needles are able to withstand prolonged temperature drops 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, tangerines, laurels, eucalyptus, cork and paper trees are justa small fraction of all kinds of representatives of deciduous evergreens. Tui, yews, cedars are representatives of conifers in a hot climate.
As mentioned above, these trees are called evergreen because they do not shed their leaves all year round, but they constantly change green mass, and photosynthesis is present in their chloroplasts depending on the state of the tree in winter.
