荒漠植物红砂水势与土壤水分的关系研究

Study on the the relationship between water potential and soil moisture of Reaumuria soongorica in desert plants

通过对内蒙古阿拉善盟额济纳旗三个典型红砂群落的红砂水势日变化及其土壤水势和土壤含水率的测定,分析红砂水势与土壤水势和土壤含水率之间的关系。结果表明:不同样地的红砂,叶水势存在差异。最高水势值出现在早晨和黎明前后,为-14.69Mpa和-14.26Mpa。最低水势值出现在正午前后,为-18.52Mpa。红砂的叶水势值早晚变化不明显,说明红砂的生存条件受到严重的水分胁迫。不同样地红砂的叶水势随着土壤含水率的降低而降低。三个样地的红砂水势与土壤水势差异性显著,均表现为:Ⅰ号样地、Ⅱ号样地>Ⅲ号样地。

Through the analysis of the diurnal variation of water potential of the Reaumuria soongorica and the soil water potential and soil water moisture content of three typical the R. soongoriea communities of Inner Mongolia Alashan Ejina. The relationship between the water potential of R. soongorica and the soil water potential and soil water moisture content was analyzed. The results showed that the R. soongorica in different plots, the leaf water potential was different. Meanwhile the highest water potential value appeared in the morning and before dawn, about --14.69Mpa and --14.26Mpa. And the lowest potential value appeared at noon, about --18.52Mpa. The change of leaf water potential value of R. soongorica was not obvious in the morning and evening, which showed that the survival condition of R. soongorica was seriously affected by water stress. The leaf water poten tial decreased with the decrease of soil water moisture content in different plots. Three plots of R. soongorica wa ter potential and soil water potential were significantly different, and all the samples are as follows： I sample plots and II sample plots 〉 III sample plots.