塔克拉玛干沙漠不同矿化度水灌溉造林试验研究

Experimental Study on Afforestation Irrigated with Saltwater with Different Mineralizations in the Taklimakan Desert

为了开发利用塔里木沙漠公路沿线的地下咸水进行防护林建设,在塔克拉玛干沙漠北缘开展了不同矿化度水灌溉造林试验。在流动风沙土和荒漠林土两种类型的土壤上,各设计6个灌溉水矿化度梯度:2g/L、5g/L、10g/L、15g/L、20g/L、28g/L,选择了4种耐盐植物:梭梭柴、头状沙拐枣、盐穗木、沙枣,研究不同类型土壤上灌溉水矿化度对植物生长的影响。结果表明:(1)随着灌溉水矿化度的增加,植物成活率下降,除2g/L水灌溉的植物生长量略低于5～10g/L外,生长量也基本随灌溉水矿化度的增加而减小;(2)土壤类型对植物的生长也有较大影响,流动风沙土中植物的成活率和生长量总体上高于荒漠林土中植物的成活率和生长量;(3)从四种植物之间的对比来看,梭梭柴适应能力最好,盐穗木和头状沙拐枣次之,沙枣适应能力最差。

In order to exploit and utilize salty groundwater with different mineralizations in the Taklimakan Desert for afforesting the shelter-forests along the Tarim Desert Highway, the experiment of afforestation with salty groundwater irrigation is carried out in the north marginal zone of the Taklimakan Desert. Six experimental afforesting plots are distributed in the regions with mobile aeolian sand soil and desert forest soil, and the forests composed of Haloxylon ammodendron, Calligonum caputmedusea Schrenk, Halostachys caspica and Elaeagnus angustifolia are irrigated with salty groundwater with mineralizations of 2g /L,5 g/L,10 g/L,15 g/L,20 g/L and 28 g/L every 10 days in April, May, September and October, every 15 days in June, July and August, and every 30 days in November, respectively. The volume of irrigation water is 1 250 m3/hm2 · time. The result are as follows: (1)The survival rate of plants is decreased with the increase of mineralization of irrigation water, and the growth of plants is also decreased with the increase of mineralization of irrigation water except the growth of plants irrigated with groundwater with mineralization of 2g/L is slightly lower than that irrigated with groundwater with mineralization of 5-10g/L; (2)Soils affect strongly the growth of plants. Generally, the survival rate and growth of plants planted in mobile aeolian sand soil are higher than that in desert forest soil; (3)The comparison reveals that the adaptability of Haloxylon ammodendron is the highest, then that of Halostachys caspica and Calligonum caputmedusea Schrenk, and that of Elaeagnus angustifolia is the poorest.