油松小枝在不同水分亏缺下恢复吸水能力的研究

A STUDY ON THE WATER ABSORBING ABILITY OF Pinus tabulaformis Carr.UNDER THE DIFFERENT WATER DEFICIT

本文对生长在呼和浩特地区16年生油松的小枝在不同水分亏缺状况下的恢复吸水能力进行了研究,结果表明:(1)油松小枝随重饱和初始水分亏缺程度增大,重饱和相对饱和含水量下降,恢复吸水能力下降。当重饱和初始水分亏缺等于初始失膨点水分亏缺时,重饱和相对饱和含水量近于1,说明短期内处于初始失膨点水分状况下的树木不受脱水的伤害,能保持其原有吸水能力。(2)油松的重饱和含水量为束缚水含量所对应的重饱和初始水势绝对值Ψ_(ow)和重饱和含水量为初始失膨点含水量所对应的重饱和初始水势绝对值Ψ_(pw)都随树木年生长发育进程变化而变化。在旺盛生长期Ψ_(pw)和Ψ_(pw)的值较小,而在年生长末期其值较大。

The characteristics of the resaturated absorbing water of Pinus tabulaformis aged 16 under the different deficit in Huhhot were studied. The results showed: (1) As the resaturate initial water deficit increased,the resaturate relative water content (RSRWC) of twigs declined, and the water absorbing ability declined. When the resaturate initial water deficit was equal to the water deficit at the initial loss point of the turgor,RSRWC was about equal to 1. It showed that the trees were not damaged in the water condition of the initial losing turgor in the short period and maintained the capability of absorbing water in it. (2) The resaturate initial water potential absolute values of the resaturate relative water content in the bound water(ψ_(bw)) and at the initial loss point of the turgor(ψ_(pw)) differed in the different growth period, ψ_(bw) and ψ_(pw) were the less in the thrive growth period, but were greater in the ripe growth period.