不同利用方式下沙地土壤凝结水变化规律野外试验分析

Field Test on Change Law of Sandy Soil Condensation Water in Different Lands

根据大量野外实测资料,研究位于科尔沁沙地南缘的不同利用方式下4个样地(受破坏的沙质草场D1、紧牧的优势沙生草甸子地C3、紧牧半流动沙地A3、紧牧固定沙地F3)在植被生长期内(5—9月)的裸地土壤凝结水变化规律。结果表明:①主凝结现象均发生在日落至次日日出期间,而日出至日落期间均发生主蒸发现象;②连通的MLS测出的凝结量均大于不连通的MLS测出的凝结量;③A3和F3的旬平均凝结量均大于C3和D1的旬平均凝结量,即沙地的凝结量大于草地的凝结量;④研究区4个样地5—9月的月平均凝结量分别为:1.04 mm、0.84 mm、0.63 mm,0.61 mm、0.59 mm,凝结量总体呈下降趋势。研究成果对沙地的生态保护具有一定的指导作用。

The change law of soil condensation water was studied in four sample fields in southern Horqin Sand Land during the vegetation growth stage （May to September）. The four sample fields are D1 destroyed sandy pasture, C3--enclosed superior sandy meadow, A3 enclosed semi-shifting sand land, and F3--enclosed fixed sand land. The results show： ①most soil water condensation occurred during period from sunset to sunrise of the next day, and most evaporation occurred during period from sunrise to sunset; ②the condensation water in connected MLS （micro-lysimeter） is more than that in not-connected MLS; ③ the average condensation of ten days in A3 and F3 is larger than that in C3 and D1; ④the monthly average condensation amount in the four sample fields from May to September is： 1.04 mm, 0.84 mm, 0.63 mm, 0.61 mm, and 0. 59 mm, showing a general descending trend. The research results have certain guiding role in sandy land ecological protection.