a) Temperature : If the temperature is more, the rate of transpiration increases. An increase in the temperature of leaf-increases the rate of transpiration in the leaf. The water is lost rapidly from the leaf. If we increase 10°C in temperature, the rate of transpiration is doubled.
(b) Wind velocity: During high wind, the transpiration becomes very active because the water vapour around the leaves is instantly removed. At. very high wind velocity, the stomata are closed because of rapid loss of water from the guard cells and the rate of transpiration is declined.
Two adaptations shown by plants to reduce transpiration are:
(i) Reduction in the surface of leaves : The surface of leaves get reduced. The leaves are modified into spines, hence no transpiration takes place. In some plants, the leaves may become needle-like, e.g., Opuntia, Euphorbia and Globe cactus.
(ii) Sunken stomata : In some, the stomata get sunk.
This also reduces the rate of transpiration, e.g., Nerium and Agave