塔里木河下游荒漠植被保护酶活性与地下水位变化的关系

在塔里木河下游的不同断面，随着距离河道由近及远、地下水埋深的不断增大，柽柳叶片的MDA含量、SOD活性随着地下水位的下降而逐渐增加，与地下水位呈显著正相关．相关系数分别为0．7464和0．5531；POD活性却随着地下水埋深的不断增大而呈下降趋势，与地下水位呈显著负相关．相关系数为0．5518。根据不同地下水位条件下柽柳叶片的MDA含量和SOD活性所反映出的适宜其生存的合理生态水位、(严重)胁迫水位并将其进行综合比较与分析，初步推断出：在塔里木河下游地下水埋深超过3．12m时．柽柳的生长即开始受到抑制，5m左右的地下水位即对柽柳造成严重胁迫，≥8．83m的地下水位则会危及柽柳的生存。

Relationship of the Protective Enzymes of Desert Vegetations with Water Table in the Lower Reaches of Tarim River

As the distance from the river course in the lower reaches of Tarim River at different planes prolonged and thus made the water table become deep,the MDA content and SOD activity of \%Tamarix ramosissima\% leaves increased with deepened water table showing a significant positive correlation with the water table with the correlation coefficients standing at 0.746 and 0.555 1,respectively,while the POD activity of the leaves declined with deepened water table showing a significant correlation with the water table with the correlation coefficient at -0.551 8.In terms of the optimal and (severely) inhibiting water tables of \%Tamarix ramosissima\% indicated by the MAD contents and SOD activities of \%Tamarix ramosissima\% leaves at different water tables,and their comprehensive comparison and analysis,it was preliminarily inferred that in the lower reaches of Tarim River,\%Tamarix ramosissima\% would be inhibited where the water table reached 3.12 m,severely inhibited where the water table reached 5 m and endangered where the water table reached more than 8.83 m.