Why do plants need water
Water is one of the key common substances required by all living things in order to sustain life. You might not realize, however, that plants require much more water than animals do. Animals can be as little 75% water by total body weight, whereas plants are typically 90% water. Plants capture and transform the light energy from the sun, using it as food molecules, and water is necessary for this process to take place and allow the transporting of valuable minerals throughout the plant’s vascular system.
The amount of water required will vary from plant to plant depending upon its type, the amount of light it gets, and its age. Plants also lose water through transpiration, which is the process of exchanging water for carbon dioxide. Plants have minute openings on their leaves called stomata through which the water can evaporate when the pores are open. At this time carbon dioxide can also be diffused through the open pores which is necessary in order for the plant to make food during its photosynthetic process.
When these pores are closed, the plants takes in very little carbon dioxide and lose little water. The times of opening and closing the stomata are balanced by the plant in order to maintain an adequate supply of carbon dioxide and ensure that it doesn’t lose too much water, thus sustaining life. For example, a mature houseplant might transpire its entire body weight every day. In human terms, this would mean an adult drinking 20 gallons of water every day, whereas humans typically drink less than one gallon of fluids in a day.
The process of absorbing and then expelling water is also facilitated by evaporation, which allows the stomata to remain open and thus allow carbon dioxide to be infused. This process cools the plant during hot and sunny weather, a process very similar to the human process of perspiration. Water is also stored by the roots in order to allow use during the winter months. Water movement from the soil is extremely slow during the cold winter months, although plants still lose water from their leaves due to the action of the wind at this time.
Winter months are when the stored water in the roots enable the plant to compensate for the water lost by the leaves. If the plant was incapable of compensating in such a way the tissues in the leaves would die and the leaves would subsequently turn brown and die – a natural process during autumn months, however one that can still occur at any point if a plant does not receive adequate water. Water also ensures the pressure of water in the plant cells which enables the plant’s survival. Without this turgidity the plant would wilt and die. Water also ensures that the plant cells expand, resulting in the growth of the plant.
Plants also require water as it acts as a solvent for the various mineral in the soil. If these much-needed minerals remained in a solid state they would not be easily and readily absorbed by plants. Water also plays its part in the process of transporting metabolic products from one part of the plant to another, as needed. Water is also an electron source of the process of photosynthesis, during which plants make their food by transforming energy from light.