图2. 主要植被类型低温抗性、干旱抗性和水力效率之间多元权衡的概念图。高(低)水力效率和低(高)低温抗性相关联, 但主动修复可影响该权衡, 低温还可影响植物的冷冻疲劳; 高(低)水力效率与低(高)干旱抗性相关联, 几乎不存在同时高水力效率和高干旱抗性的植物, 但具有低水力效率和低干旱抗性的植物; 干旱胁迫可增加低温抗性(不同时), 反之亦然, 干旱和低温同时发生增加水力导度丢失量, 但两者对水力系统的影响并不相关。

Fig. 2. A conceptual diagram of multiple trade-offs among low-temperature resistance, drought resistance and hydraulic efficiency of the major vegetation types in the world. High (low) hydraulic efficiency is associated with weak (strong) low-temperature resistance, but the capacity of positive refilling embolism may influence the trade-off between hydraulic efficiency and low-temperature resistance, and low-temperature also affects the plant’s frost fatigue. High (low) hydraulic efficiency is associated with weak (strong) drought resistance, but many species have both low hydraulic efficiency and drought resistance rather than high hydraulic efficiency and drought resistance. Drought stress may increase low-temperature resistance (asynchronous), and vice versa; concomitant drought and low-temperature stresses aggravate the loss of hydraulic conductance, but there are no related impacts of drought and low-temperature stresses on the hydraulic system.