云贵高原石漠化与古气候演变分析

Analysis of Paleoclimatic Evolution and Rocky Desertification in Yunnan-Guizhou Plateau

中国南方喀斯特地区石漠化分布广泛,其中云贵高原分布最为集中,石漠化程度最为强烈。对云贵高原地区4.5ka.B.P.的石笋、孢粉和气候记录进行分析发现,云贵高原地区在4500～1000a.B.P.期间经历了3个干旱期与2个湿润期,3个干旱期分别是4500～3400、3100～2650、2000～1000a.B.P.。1000a.B.P.以来,气候的干湿振幅有越来越大的变化趋势。干旱期由于生态退化和人类活动的不断增强,造成地表覆被不断破坏,基岩逐渐裸露;转入湿润期后,越来越多的降水造成更多的水土流失,使石漠化逐渐出现,范围不断扩大,程度不断加深。

Rocky desertification is widely spread in south China Karst district,especially on the Yunnan-Guizhou plateau,the degree of rocky desertification is the most intense.From the sporopollen,stalagmite and climate records,it was found that there are three continued arid periods：4 500-3 400,3 100-2 600,2 000-1 000a.B.P.Since 1 000a.B.P.,the aridity was more intense during arid times,and the humidity was also more intense during humidity.The blankets on the earth＇s surface were destroied gradually during arid period for the ecological degradation and human activities,and the bed rock emerged gradually.The water loss and soil erosion became more serious during humid period,and the range of the rocky desertification expanded gradually,the degree became more deepen.