suck fast and swallow slow........
Plants' Cooling Systems
A plant and a piece of stone in the same place do not warm up to the same degree, even though they receive the same amount of solar energy. Every living creature will experience negative effects if it stays out in the sun. So what is it that enables plants to be minimally affected by the heat? How do plants manage this? Why does nothing happen to plants even in great heat, even when its leaves burn in the sunshine all through a hot summer?
Apart from their own internal warming, plants also take in heat from the outside and maintain the temperature balance in the world. And they themselves are exposed to this heat while carrying out this heat-retention process. So, instead of being affected by the ever-increasing temperature, how is it that plants can continue to take heat in from outside?
Considering that plants are constantly under the sun, it is natural that they should need more water than other living things. Plants also constantly lose water by the perspiration on their leaves. In order to prevent such water loss, the leaves, the surface of which are always turned towards the sun, are generally covered in a waterproof protective wax known as the cuticle. In this way water loss on the upper surfaces of leaves is prevented.
But what about the under surfaces? Because the plant loses water from there, the pores whose function is to enable the diffusion of gases are generally on the bottom surfaces. The opening and closing of the pores regulates the plant's taking in enough carbon-dioxide and giving off enough oxygen, but not in such a way as to lead to water loss.
In addition to this, plants disperse heat in different ways. There are two important heat dispersal mechanisms in plants. By means of one of these, if the temperature of a leaf is higher than that around it, air circulates from the leaf towards the outside. Air changes stemming from heat distribution lead to the air rising, because hot air is less dense than cold. For this reason the hot air on the surface of the leaf rises, leaving the surface. Because cold air is denser, it descends to the surface of the leaf. In this way heat is reduced and the leaf is cooled down. This process goes on for as long as the temperature on the surface of the leaf is greater than that outside. In very dry environments, such as deserts, this situation never changes.
By means of the other heat dispersal system of plants, leaves can perspire by giving off water vapor. By virtue of this perspiration, the evaporation of water permits the plant to cool down.
These dispersal systems have been designed to suit the conditions where the plant lives. Every plant possesses the systems it needs.
This activity of plants could be described as a kind of water engineering. The trees in a thousand square meter area of forest can comfortably put 7.5 tons of water into the atmosphere. Trees are like giant water pumps, passing the water in the soil through their bodies and sending it into the atmosphere. This is a most important task. If they did not possess such a feature, the water cycle on the Earth would not happen as it does today, which would mean the destruction of the balances in the world.
Although their stems are covered with a wooden, dry substance, plants can pass tons of water through their bodies. They take this water from the soil, and after using it in various parts of the high technology factories in their bodies, give it back to nature as purified water. At the same time that they do this, they also separate part of their intake of water with the aim of using the hydrogen in the nutrition production process.