松嫩沙地晚更新世以来的孢粉记录及古植被古气候

松嫩沙地的形成演化经历了一个漫长的地质历史过程, 孢粉记录反映出这个地区从晚更新世以来植被曾被发生过多次更替, 经历了半荒漠(半荒漠草原)→疏林草原→干草原的演替, 气候经过多次冷暖-干湿波动, 沙漠化也经历了多次扩张和收缩。与中国北方其它沙漠化土地一样, 气候变干是松嫩沙地形成和扩张的决定因素, 而人类的各种活动对这一地区的土地沙漠化起着诱发和促进作用

THE SPORO POLLEN RECORDS AND VEGETATION AND CLIMATE HISTORY IN SONGNEN SANDY LAND SINCE EPIPLEISTOCENE

Located on the semiarid-semihumid fringe in the north of China, the Songnen sandy land has plenty of precipitation comparing with other desertified lands of China. Therefore its environment is sensitive to change. The formation and development of Songnen sandy land have a long geologic and historic processes. The sporo-pollen records of this region indicate that the vegetation in this area has a succession of semidesert(semidesert grassland) →grassland→sparse woods grassland→dry grassland, and the climate has been changing between cold(dry) and warm(wet), along with which the desertified land expanded or reduced since Epipleistocene. Similar to other desertified lands of North China, the Songnen sandy land formed under the dry-cold climate and the desertification was induced and aggravated by human activities.