科尔沁沙地巴克窑地区近150年的环境演变*

在沉积和花粉分析的基础上,对科尔沁沙地东南部巴克窑地区过去150年的植被和环境演变进行了重建。巴克窑等湖泡的诞生时间是在上个世纪前期,约1837年前后。这个时间也正是科尔沁沙地东南部地区首次大规模人口移入和垦荒年代。突然增加的人类活动导致了沙丘植被的迅速破坏,而植被减少和沙丘活化引起区域水文循环的重新调整,即原来通过植物蒸腾作用输出的水量明显减弱,致使地下潜水位上升,形成一系列湖泡。以后,沙地系统的演化主要是在人类活动、气候和系统内部反馈机制的共同作用下完成的。

ENVIRONMENTAL CHANGE IN THE LAST 150 YEARSIN BAKEYAO, SOUTHEASTERN HORQIN SANDLAND,NORTHEAST CHINA

Desertification in North and Northeast China has become a commonly concerned problem among environmental scientists. The desertification in the Maowushu and Horqin Sandlands of Inner Mongolia Autonomous Region is the most serious in the country. In order to investigate the past human impact on sand dune mobilization and land degradation, we collected two sediment cores in Bakeyao Lake, Southeastern Horqin Sandland, and analyzed the pollen and algae spore from one of them. The result shows that the little lake was formed in 1837, when the first migrates from Shandong and Hebei Provinces arrived in the study area for agriculture production. The original sand dune vegetation was greatly destroyed by the early settlers, and a series of little lakes were formed owing to the reduced plant evapotranspiration. The later changes of the lake and sand land system were controlled by the interaction among human activities, climates and the initial intervention. Since the early ninetieth, human activities have been the dominating factor in the sand land environmental changes. The feedback process within the sand land system may have been of importance.