How Do Desert Plants Conserve Water?
Photosynthesis and Transpiration Plants make energy through photosynthesis, using sunlight and carbon dioxide from the air. To obtain carbon dioxide, the leaves must open their stomata, microscopic pores that allow the gas to diffuse into the leaf. Stomata increase the surface area of the leaf, causing evaporation of water that the plant must replace in order to keep leaves from wilting. Thus, photosynthesis is a tradeoff: the more food the plant makes, the greater its water requirements. Specializations of Desert Plants In the desert, water is a precious resource, so desert plants must minimize water loss in order to stay alive. Most desert plants have small, thick leaves, so their surface area is smaller than that of plants in a moist environment. They often have a thick waxy coating over the leaves, which minimizes water loss from anywhere but the stomata. Guard cells open and close the stomata, responding to potassium levels in the leaf, carbon dioxide levels, and their own interna
