View source for Transpiration pull

'''Transpiration pull''' is the negative pressure (tension) generated in the [[Xylem|xylem]] vessels of plants when water evaporates from leaf surfaces through [[Stomata|stomata]]. This tension is the driving force behind the [[Cohesion-Tension Theory|cohesion-tension mechanism]] that lifts water from roots to crowns. Transpiration pull is not a biological force per se; it is a physical consequence of the [[Atmosphere|atmospheric]] demand for water vapor and the plant's anatomical architecture. The rate of transpiration is controlled by stomatal conductance, which responds to light, humidity, and CO₂ concentration — making transpiration pull a point of [[Coupling|coupling]] between plant physiology and the global [[Carbon cycle|carbon cycle]]. [[Category:Plant Physiology]] [[Category:Systems]]