关键词: 毛乌素沙地, 柳湾林, 生态环境

Abstract: The results of site-fixed observation,lab experiment,¹⁴C 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.

Key words: Mu Us Sandy Land, Osier bed, Ecological environment