there are a couple of environmental factors that affect the rate of transpiration. they include:
I) wind:in a windy environment there is easy movement of moisture hence it does not accumulate on the leaf surface. this helps to increase diffusion gradient between the intercellular spaces in the leaf and in the environment there4 the rate of transpiration is increased. in a calm environment moisture accumulates on the surface of a leaf there4 reducing the diffusion gradient there4 reducing the rate of transpiration
ii) atmospheric pressure :in low lands there is high atmospheric pressure than in the highlands. the more the atmospheric pressure the more the pressure exerted on the cells of the leaves there4 reducing the rate of transpiration.
iii) humidity:the more the humidity in the atmosphere the less the rate of transpiration. this is due to low diffusion gradient due to accumulation of water vapour on the surface of the leaf
iv) temperature:a rise in temp increases the water vapour holding capacity of air in the air spaces within the spongy mesophyll layer. the water vapor pressure in the intercellular spaces increases causing an increase in diffusion gradient between the intercellular spaces and the environment there4 increasing the rate of transpiration. decrease in temp decreases the water vapor holding capacity in the intercellular spaces there4 diffusion gradient is lowered there4 reducing the rate of transpiration.
