塔克拉玛干沙漠不同立地条件下咸水滴溉苗木的生长差异

Analysis of Growth Differences of Seedlings Irrigated with High Degree of Mineralization Water

为了开发利用塔克拉玛干沙漠地下高矿化度咸水进行沙漠公路绿化,2003年在肖塘进行了高矿化度地下咸水灌溉实验。实验点选择在流动沙丘和丘间平地上,按照荒漠林土覆沙厚度差异和坡向不同,选择了9种不同的立地条件的实验点。样地中栽植梭梭、柽柳、盐穗木等3种植物。实验结果如下:(1)立地条件对植物生长的影响主要是通过其对水分和太阳辐射的差异分布而引起的;(2)不同植物种对于高矿化度的咸水灌溉适应性不同,适应性因土壤母质条件的差异而变化;(3)植物生长的不同阶段,生长限制因子不同,在成活时期水分因子是其限制因子,而在生长时期中,在水分满足的条件下,地表太阳辐射能量是其限制因子。

In order to explore and use high mineralization degree ground water in Taklimakan Desert for the instruction of the shelter forest along Tarim desert highway, in 2003 we had done some experiments on drop irrigation with high degree mineralization salt water about 28 g/L in Xiaotang in the north fringe of Taklimakan desert. According to the depth of covering sand layer in the upper desert forest soil in inter-dune area and the slope orientation of shifting sandy soil on sand dunes, nine sites were chosen for experiment. Such five kinds of seedlings as Haloxylon ammodendron, Tamarix hispida, Halostashys caspica were planted in every site. We noted the total amount of survival seedlings in each site from May to August by the cycle of 10 days and measured the seedling growth from July to October by the cycle of 10 days. The results is as follow: (1)The effect of different sites on the seedling growth primarily results from sites' different distribution to soil humidity and ground solar radiation; (2)The seedlings' adaptation to irrigation with high degree of mineralization salt water about 28 g/L vary among different plants and between shifting sandy soil and desert forest soil; (3) The limit factor to seedling growth isn't the same at the different stage of plant growth: at the early (survival ) stage, soil humidity is the limit factor, but at the growth stage, if soil humidity is enough ground solar radiation becomes the limit factor.