松辽盆地南缘第四纪环境特征——以四平-双辽地区为例

四平-双辽地区处于中国北方农牧业交错地带，也是全球第四纪古环境变化较敏感地区.在深入论述孢粉特征及生态背景、古气候特征、环境变迁规律的基础上.根据孢粉组合特征，划分了森林草原、疏林草原、草原3个生态背景；总结了第四纪以来气候环境具周期性变化的特点；指出了松辽盆地南缘第四纪生态环境历经3次沙地扩展和2次收缩变迁过程；提出了近代生态变化既有自然因素，也有人为因素的新认识，并提出了防止沙漠化趋势的有关措施.

QUATERNARY ENVIRONMENT CHARACTERISTICS IN THE SOUTHERN MARGIN OF SONG-LIAO BASIN: A case study of Siping-Suangliao area

The Siping-Shuangliao area,situated in the overlapping zone of agriculture and livestock husbandry in North China,is one of the sensitive regions to global paleoenvironmental changes during Quaternary. With discussion on the sporopollen characteristics,ecologic background,paleoclimate and environmental changes,three kinds of ecologic background,i.e. forest-steppe,veld and grassland,are recognized on the basis of sporopollen characteristics. The climate and environment have periodically changed since Quaternary. The Quaternary ecologic environment on the southern margin of Song-Liao basin Ires undergone a process with three times of sandy ground expansion and twice contraction. The modern ecologic changes are caused by both natural and artificial factors.