Factors affecting transpiration

The rate of is affected by several factors. These include:

The table below explains how factors increase the rate of transpiration:

Factor	Change in factor that increases transpiration rate	Explanation
Temperature	Increase	Increases molecular movement so that more water molecules evaporate from cell surfaces and the rate of diffusion of water molecules from the leaf is increased
Humidity	Decrease	Reduces the concentration of water molecules outside the leaf; diffusion of water from the leaf increases
Air movement	Increase	Removes water vapour from leaf surfaces; more water diffuses from the leaf
Light intensity	Increase	Increases the rate of photosynthesis; stomata open so that water diffuses out of the leaf

Factor	Temperature
Change in factor that increases transpiration rate	Increase
Explanation	Increases molecular movement so that more water molecules evaporate from cell surfaces and the rate of diffusion of water molecules from the leaf is increased

Factor	Humidity
Change in factor that increases transpiration rate	Decrease
Explanation	Reduces the concentration of water molecules outside the leaf; diffusion of water from the leaf increases

Factor	Air movement
Change in factor that increases transpiration rate	Increase
Explanation	Removes water vapour from leaf surfaces; more water diffuses from the leaf

Factor	Light intensity
Change in factor that increases transpiration rate	Increase
Explanation	Increases the rate of photosynthesis; stomata open so that water diffuses out of the leaf

Plants living in different habitats have adaptations to resist extremes of these factors.

Question

What conditions will decrease the rate of transpiration?