毛乌素沙地生态环境失调的研究

柳湾林分布区定位观测试验和室内实验、１４Ｃ测年、孢粉分析研究结果表明，毛乌素沙地生态环境失调的决定性因素是地质构造和地势，它决定了该地区干旱气候条件和丰富的沙源。第四纪以来的３００多万年间，气候干湿相间出现，总趋势向干旱发展，全新世以来更加明显。植被随气候变化演替，森林草原植物群落逐渐被旱生灌木植物群落代替，保持脆弱的生态平衡。干旱导致地下水位下降、水质恶化是沙区生态环境失调的主导因子，人为破坏生物群落使生态环境失调加速也是不可忽视的因素

STUDY ON THE ECO ENVIRONMENT OF MU US SANDY LAND

The results of site fixed observation,lab experiment, 14 C dating, and sporo pollen analysis show that the determinant factor leading to ecological disturbance of Mu Us Sandy Land is geological structure and terrain which determines dry climate and abundant sand source in this area. During more than 300 years since Quaternary, the climate fluctuated between humidity and drought, and towarded to a general trend of drought, especially since Holocene. The vegetation succession from forest and grassland community to xerophilous shrub community takes place with the climate change. The falling of groundwater level and the deterioration of water quality due to drought are the leading factors of ecological environment disturbance in sandy area. The disturbance of human activities to ecological environment can not also be disregarded. The destruction to biological community due to human activities has accelerated the processes of ecological environment change.