三树种P－V曲线水分参数的比较研究

应用Ｐ－Ｖ技术研究了野外条件下海红、山杏和沙枣三个树种的水分参数（ψｓ＾ｓａｔ，ψｓ＾ｔｌｐ，ＲＯＷＣｔｌｐ，ＲＷＣｔｌｐ和ＡＷＣ）及其季节变化规律。探讨了树种对干旱胁迫的适应性反应。结果表明：树木各水分参数的季节变化规律与气候条件，尤其是水分条件相关，并与树木长期适应当地气候条件而形成的物候节律有关。嫩枝生长阶段是树木抗旱性最弱的时期，随着干旱锻炼过程的进行及小枝木质化程度的提高，树木的抗旱性不

A Comparative Study on Water Parameters of Three Species of Trees by Using P-V Curve

The water parameters and their seasonal changes of Malus micromalus,Prunusameniaca var ansu and Elacagnus angustifolia are studied by using P-V technique under field condition. The adaptive responses of the tested trees are explored under drought stress condition. The results show that the regular patterns of the seasonal change of water parameters for thesespecies are related to climate conditions,especially the water element,and the phenologilcal char-acteristics formed by adapting to the climate condition over a long period.Within growing sea-son,the weakest point of drought tolerance of these species is in spring and early summer whenyoung branches and leaves are growing,The drought tolerance becomes stronger with droughthardening and branches maturating. The idex of drought tolerance fluctuates during the growingseason. The value of and drotight tolerance index can be used as an indicator for judging thedrought tolerance of the three species.