Rate of Transpiration
Biology: Cambridge International GCSE Supplement, topic 8.3.4
Factors Affecting the Rate of Transpiration
If a plant loses more water by transpiration than it brings up from the roots, it loses water pressure in the xylem, plant cells become flaccid and the whole plant will wilt (droop). Environmental factors affect the rate of transpiration:
Temperature
- Increased temperature makes water evaporate faster, which increases the rate of transpiration.
Humidity
- Increased humidity increases the amount of water in the air. This makes it more difficult for water to evaporate.
- Increasing humidity decreases the rate of transpiration.
Test yourself on Rate of Transpiration
Which of the following would increase the rate of transpiration?
Wilting happens when...
What process happens because water pressure is lost in the xylem?