Gas exchange is the movement of gases between a plant and its surrounding environment. Plants absorb carbon dioxide (CO₂) for photosynthesis and release oxygen (O₂) as a byproduct. They also consume oxygen and release carbon dioxide during respiration, which occurs continuously in living tissues.
Most gas exchange occurs through stomata, microscopic pores in the epidermis of leaves and stems. When stomata open, carbon dioxide enters the plant while oxygen and water vapour exit. The rate of gas exchange is influenced by factors such as light intensity, temperature, humidity, air movement, carbon dioxide concentration, and stomatal opening.
Gas exchange is closely linked to water use because carbon dioxide uptake and water loss occur through the same stomatal pathways. Plants must balance the need for carbon dioxide to support photosynthesis against the need to conserve water, particularly during drought, heat, or other environmental stresses.
See Also
