When plants close their stomata what is effected

The rate of gaseous exchange

Explanation:

In plants gaseous exchange occurs mainly in leaves and to a lesser extent in roots and stems. In leaves, the structures involved in gaseous exchange are the stomata. During the day, carbon dioxide from the atmosphere diffuses into the large air spaces of the spongy mesophyll through the stomata. Excess oxygen diffuses from the leaf down a concentration gradient through the stomata into the atmosphere.