Question

Write the external factors that influences transpiration.

Answer 1

1. Light intensity: Stomata open during the day for photosynthesis, leading to higher transpiration, whereas they close at night and open only partially on cloudy days to reduce water loss.
2. Temperature: High temperatures accelerate the evaporation of water, thereby increasing transpiration, while a decrease in temperature slows down evaporation and reduces water loss.
3. Wind velocity: Faster wind speeds increase transpiration by quickly removing the accumulated water vapor around the leaf, which prevents the surrounding air from becoming saturated.
4. Humidity: High humidity in the outside air reduces transpiration because the damp atmosphere slows down the outward diffusion of water vapor from the stomata.
5. Atmospheric pressure: An increase in atmospheric pressure causes a decline in the transpiration rate because higher pressure restricts the free diffusion of escaping water vapor.
6. Carbon dioxide: Elevated levels of carbon dioxide in the surrounding air trigger the stomata to close, which directly results in a decrease in the plant's transpiration.