Evaporation vs. Transpiration

Difference between evaporation and transpiration

There are two scientific processes that take place to remove water from the surface of the earth – evaporation and transpiration. These two processes are similar in that they are responsible for releasing water into the air but there are differences in the features of each one.

What is evaporation?

Evaporation is the process by which water is changed from its present state into a gas called water vapor. It takes energy to perform this feat. It takes place on the surface of the water and in this way it is different from boiling water because when you boil water it affects the whole mass of water. The energy needed for evaporation takes place as water molecules keep colliding with one another. Often the transfer of energy is so one-sided that the molecules of water that are closest to the surface are the ones that are released into the air.

Evaporation is an essential part of the water cycle on earth. The heat from the sun causes the water to evaporate and when the water vapor hits the cold air of the clouds, it then falls back to the earth as precipitation of various kinds.

What is transpiration?

Transpiration is the name given to the process in which plants lose water through the stomata. The stomata are the small openings that are found on the underside of the leaves of plants and that are connected to the vascular tissues. This process depends heavily on the amount of water that is present in the soil as well as the amount of humidity in the air.

Plants need transpiration in order to grow and thrive. It is through this process that the roots are able to get the nutrients to the soil and by which they are then carried to the cells of the plant. The process is one that prevents plants from becoming overheated. Plants that can open and close the stomata lose less water through transpiration than the plants that do not have this ability. This adaptation is usually found in plants that grow in very hot climates.

When you add the amount of water lost from the earth in evaporation and the amount that plants lose through transpiration, the combined process is called ET (evapotranspiration).


  1. Evaporation and transpiration are two natural processes that release water into the atmosphere.
  2. Evaporation takes place on the surface of bodies of water when the energy caused by the movement of molecules causes some molecules of water to be released into the air. This is a very important part of the earth’s water cycle.
  3. Transpiration is the process in which water is released from plans through the stomata. It keeps the plants from becoming overheated in hot weather.