The rate of transpiration 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|
Plants living in different habitats have adaptations to resist extremes of these factors.
What conditions will decrease the rate of transpiration?