Select Board & Class



Transpiration (Group B)

Factors affecting Transpiration

The factors affecting transpiration can be classified into two categories:

  • External Factors
  • Internal Factors
External Factors:
  • Light: During the day time stomata is open and facilitates transpiration.
  • Wind Speed: Rate of transpiration increases with the speed of wind.
  • Humidity: Rate of transpiration decreases with increase in humidity.
  • Temperature: High temperature results in more transpiration.
  • Atmospheric pressure: Decreased atmospheric pressure increases the transpiration.
  • Carbon dioxide: Increase in level of CO2 causes decrease in transpiration.

Internal Factors:
Transpiration decreases when water content of the leaves decreases due to insufficient absorption by the root.

Adaptations in Plants To Reduce Excessive Transpiration

  • Sunken stomata
  • Less stomata
  • Narrower leaves
  • Loss of leaves
  • Reduced exposed surface
  • Thick cuticle
Significance Of Transpiration
  • Suction force: It provides transpiration pull which is responsible for the upward movement of water in tall plants.
  • Cooling effect: Evaporation causes cooling. Hence, transpiration helps plants in hot sunny days.
  • Distribution of water and minerals: Since leaves are present at the tips of all branches, transpiration helps to draw water and minerals towards them, and thus helps in their distribution through out the plant's body.
Transpiration affects Climate
  • Most of the plants on a daily basis loses litres of water that is released in the atmosphere.
  • The released water increases moisture in atmosphere that brings rain.
Relationship of Transpiration with Photosynthesis
  • Process of photosynthesis requires water. Xylem provides water to the site of photosynthesis (leaves).

  • As the water evaporates, in order to maintain a thin film of water over the cells, water is pulled from the xylem to the leaves.

  • Also, due to the lower concentration of water i…

To view the complete topic, please

What are you looking for?