Many of the inhabitants have little idea of the importance of vegetation for life on the planet. Meanwhile, it is plants that provide replenishment of the Earth’s atmosphere with oxygen, serve as food for herbivores and other forms of life, process biological waste and carbon dioxide.
And even the water cycle in nature is unthinkable without flora! Do you know the significance of evaporation for plants, as well as for the biosphere as a whole? If not, we have prepared this article especially for you!
How does water enter plant tissues and cells?
Through the roots and root hairs, the liquid is absorbed, and then spreads throughout the plant. As in the case of animal cells, water is life itself for them, since plant tissue consists of more than 90% of the liquid.
Molecules of numerous salts of trace elements that are dissolved in a liquid exert a certain pressure on the cell membrane, since they cannot pass through it under ordinary conditions.
This phenomenon is called osmotic pressure. Of course, water itself in the form of an isotonic salt solution also stretches the elastic cell membrane. Voltage is indicated by the word "turgor." Simply put, it is due to water and salts dissolved in it that plant tissue is maintained in an elastic and elastic state. But this happens only in conditions of normal water-salt metabolism.
So what is the significance of evaporation for plants? As soon as part of the water from the cell evaporates, the concentration of salts in it becomes larger. The concentrated solution begins to draw water through the cell membrane until it goes into an isotonic state. The difference between the concentration of salts in the cell and the water that enters the plant determines the strength of absorption.
The importance of evaporation in this process
On the surface of the sheet there are tiny holes, stomata. It is with their help that the plant evaporates moisture from its surface. And what is the significance of evaporation for plants in this case? Most important, since it is due to evaporation and increasing the concentration of salts in the cell that a suction force is created, which contributes to the flow of water and nutrients into cells and tissues.
Actually, all the movement of liquids in a plant becomes possible only due to the evaporation process. It is not worth considering that this phenomenon is uncontrollable: the stomata cusps can open and close by some fractions of a percent, ideally regulating the rate of moisture transfer to the external environment. In complete darkness and in the midday sun, they completely overlap, preventing dehydration of the plant.
What else determines the flow of water into the cell cytoplasm
If the intensity of fluid movement in plant tissues depended solely on evaporation, it would completely stop at night. The fact is that some of the water always evaporates through the cuticle, but its amount is very small.
If you carry out the simplest experiment, cutting the plant near the very root neck, you will quickly notice that the water still continues to come from the roots. This proves that the liquid moves along the tissues of plants also due to the difference in the concentration of solutions.
In addition, the root pressure also plays a huge role in this process, due to which the plant distills moisture into the "vessels" formed by layers of dead cells.
Since there are no living tissues there, the water freely reaches the leaves, where it evaporates through the stomata mentioned above.
So what is the significance of evaporation for plants, if we summarize all the information received? Firstly, with water moving as a result of this phenomenon, nutrients are carried throughout the plant. Secondly, continuous evaporation is extremely important for plants growing in the southern regions. Evaporating, the water cools the entire plant.
As you can see, water evaporation plays a vital role in plant life.
Percentage of Absorbed and Evaporated Moisture
The simplest experiments of scientists have shown that out of a thousand volumetric parts of the water entering the plant, no more than three are absorbed. All other 997 parts by weight evaporate. In our climate, plants need to evaporate about a kilogram of water to form a similar amount of dry matter. In a word, the intensity of this phenomenon directly depends on the climatic conditions in your area.
Experiments of scientists
Schlessing scientist spent a couple of centuries ago an entertaining experience. He took three bushes of tobacco, two of which he planted in open ground. The difference between them was only in the composition of the soil and the place of planting. He rooted the third plant in a pot, which was kept indoors, but was constantly covered with a cap.
As a result of his experiments, he found that the first two bushes during the entire growing season evaporated almost three times as much water, but at the same time formed two (!) Times less dry matter than “indoor” tobacco.
But! When he burned the first two plants, he was surprised to find out that they contain one and a half times more ash elements. Thus, inadequately strong evaporation of moisture by plants in conditions of particularly hot regions or dry periods leads to excess production of mineral substances that they actually do not need.
Importance of evaporation in crop life
This is especially true in relation to crops. Among other things, this phenomenon also reduces their nutritional and taste value, since an excess of ash substances negatively affects these indicators. Accordingly, the increased evaporation of water by the plant also contributes to severe soil depletion, since many mineral substances leave it.
Why are we telling all this? Just not everyone understands that in nature everything is interconnected. It is no coincidence that in hot regions the soil needs to be fertilized much more often. In addition, in such climatic zones it is much more sensitive to the application of mineral fertilizers, which should also be taken into account when developing a professional agricultural technique for growing certain crops.
Effect on the taste and nutritional qualities of plants
However, from ancient times, plant breeders have noticed that in dry years, when plants have to be constantly irrigated, their nutritional value drops sharply when compared with more successful years in terms of precipitation. Thus, evaporation in the life of plants plays a much greater role than can be thought of from the outside.
It is not surprising that in particularly hot years, when the amount of moisture in the soil decreases sharply, and the evaporation capacity drops to a minimum, plant growth and development practically stop. Under these conditions, they can no longer cool themselves, and therefore often dry out of tune.
