关键词: 科尔沁沙地, 土地沙漠化, 成因, 发展趋势

Abstract: Viewed from the results of investigations and expertiment analysis to Horqin sandy land,it is evident that the initial age of the desertification in the area can be at least traced back to early-middle Pleistocene,and its evolutional processes not only have the positive changes from non-desert to desertification environment but also have the reverse changes from desertification environment to non-desertification one,and two directional changes have alternately occurred in time since then,The bioclimatic zone in the area undertook a series of the alternations from arid.cold and windy steppe,desert steppe to warm-wet or warm,cool and wetter forest steppe,sparse woods steppe,The changes of the desertification and bioclimatic belt are concordant with global climatic changes and the horizontal bioclimatic zone alternations of North China caused by winter-summer monsoon activities.It is therefore obvious that the trend of the desertification in the area will depend mainly on that of global climatic changes today.

Key words: Horqin sandy land, Desertification, Desertification cause and trend