The ecological significance of long‐distance water transport: short‐term regulation, long‐term acclimation and the hydraulic costs of stature across plant life forms

作者：Maurizio Mencuccini · 发表于：Plant Cell & Environment · 年份：2003 · DOI：10.1046/j.1365-3040.2003.00991.x · 被引用次数：355 · 研究领域：Plant Water Relations and Carbon Dynamics、Tree-ring climate responses、Soil and Unsaturated Flow

ABSTRACT Plant hydraulic conductance, namely the rate of water flow inside plants per unit time and unit pressure difference, varies largely from plant to plant and under different environmental conditions. Herein the main factors affecting: (a) the scaling between whole‐plant hydraulic conductance and leaf area; (b) the relationship between gas exchange at the leaf level and leaf‐specific xylem hydraulic conductance; (c) the short‐term physiological regulation of plant hydraulic conductance under conditions of ample soil water, and (d) the long‐term structural acclimation of xylem hydraulic conductance to changes in environmental conditions are reviewed. It is shown that plant hydraulic conductance is a highly plastic character that varies as a result of multiple processes acting at several time scales. Across species ranging from coniferous and broad‐leaved trees to shrubs, crop and herbaceous species, and desert subshrubs, hydraulic conductance scaled linearly with leaf area, as expected from first principles. Despite considerable convergence in the scaling of hydraulic properties, significant differences were apparent across life forms that underlie their different abilities to conduct gas exchange at the leaf level. A simple model of carbon allocation between leaves and support tissues explained the observed patterns and correctly predicted the inverse relationships with plant height. Therefore, stature appears as a fundamental factor affecting gas exchange across plant ...