The roots of plants in the warm season constantly absorb water from the soil and carry it through the vessels of the wood to the leaves. Inside the leaf, water passes through the intercellular spaces to the stomata and evaporates through them (this process is called transpiration).
At the same time, the plant removes excess water from the body and thus makes room for admission by absorbing the roots of water with minerals dissolved in it.
Evaporation promotes the movement of water in the plant. In addition, by evaporating, the water protects the leaves from overheating by the sun’s rays.
Conditions affecting water evaporation
Evaporation depends on environmental and stomatal conditions. Under different conditions, even the same plant will evaporate different amounts of water. For example, less water evaporates in cloudy weather than on a sunny day. In strong dry winds, evaporation is stronger than in calm weather. On hot days, plants are at risk of overheating from sunlight. When evaporated, the leaves are cooled, and the plant does not overheat.
In plants, evaporation is regulated by the opening and closing of the stomata. In some plants, the stomata are open only during the day, and close at night.
Different plants evaporate different amounts of water. The larger the leaves of plants, the larger their surface, the more moisture evaporates. So, corn evaporates 0.8 liters of water per day, cabbage – 1 liter, oak – 50 liters, and birch – more than 60 liters of water.
Plants that live in conditions of a lack of moisture have developed various adaptations to its excessive loss: thickened outer walls of leaf skin cells, waxy coating, thick hairs. These devices not only prevent evaporation, but also help reflect the sun’s rays. In addition, plants constantly experiencing a lack of moisture have small leaf blades.