Lesson 6: Transpiration

We mentioned in the previous section that trees are involved in the process of "transpiration".

What exactly is transpiration?

• In order to understand how forests regulate water flow, we must understand how water circulates throughout the environment. The earth has a limited amount of water. That same water keeps going around and around in what we call the water cycle.

• In brief, the water cycle begins with precipitation (rain, hail, and snow) falling to the ground.

  • This water seeps into the ground or flows over the earth's surface until it enters a stream, eventually flowing into the oceans.

  • Water is returned to the atmosphere through evaporation from water bodies and transpiration from plants, notably trees.

  • Transpiration is the process by which water vapour is released into the atmosphere through small openings in the leaves.