Question

How does relative humidity affect transpiration?

Answer 1

Effect of relative humidity on transpiration:

1. Transpiration is the biological process by which water from the aerial portions of plants is lost as water vapor.
2. Relative humidity is the amount of water vapor in the air in comparison to the amount of water vapor that air can hold at a given temperature.
3. The relative humidity (RH) of a hydrated leaf will be close to 100 percent, as seen in the atmosphere on a rainy day.
4. Any decrease in the amount of water in the atmosphere creates a gradient, causing water to move from the leaf into the atmosphere.
5. When the relative humidity is high, the atmosphere contains more moisture.
6. This lowers the driving force for transpiration.
7. Lower relative humidity levels correspond to less moisture in the atmosphere and thus a higher driving factor for transpiration.