二万年来长江中下游自然环境变迁及其发展趋向探讨  

A STUDY OF ENVIRONMENT IN TNE MIDLOWER YANGJZE RIVER VAIIEY SINCE 20000A.B.P

作　　者：徐馨[1] 

机构地区：[1]南京大学

出　　处：《火山地质与矿产》1992年第1期1-11,共11页Volcanology & Mineral Resources

摘　　要：20000～15000a.B.P.间气候最冷,生长喜冷的针叶林和干旱草原植被.在14780±700a.B.P.出现了最低海面(-154m);15000～13500a.B.P.,气候较暖湿,海面上升,生长阔叶混交林;13500～10500a.B.P.,气候有2次温暖和3次较冷,在暖期生长针阔叶混交林.较冷期则出现森林草原和草原.最低的温度比现在低5～7;一万多年来的冰后期,气候变化分为5个新冰期(包括小冰期)和5个新高温期(包括小气候最宜期).最高气温比现在高2～3℃,出现在5000～4000a.B.P.之间;最低温度比现在低3～5℃最高海面在6500～6300a.B.P.,高出现在海面4～5m.在温暖期中生长常绿一落叶阔叶林中亚热带针阔混交林;在较冷期间,生长落叶阔叶林,针叶林或草原草地.在人类影响或自然发展之结果,未来环境变化有可能向干暖气候和高海面演变,或向干冷气候和海面下降转变.这些变化将对长江中下游带来意外的灾难.The environmental changes in Mid-lower Yangtze river valiey since 20000 a.B.P. may be summarized as follows: From 20000 to 15000 a.B.P., the climate was coldest, the vegetation was colder coniferous forests and the droughty steppe plants. The lowest sea level (-154m) appeared in 14780 ± 700a.B.P.. At the 15000~ 13500a.B.P., The climate was warmer and wet, the seaa level raised, the vegetation was broad-leaf mixed forest. During 13500~ 10500a.B.P., the climate were tow warmer and three colder, the vegetation shows that in the warmer periods, with the mixed coniferous and broad-leaf forest, and in the colder periods, with the steppe and forestOsteppe. The lowest temperaature was 5 ~7℃ lower than the present. The Pastglacial period since 10000+a.B.P., the climate changes can be divided into five New glacial period (consist of Little Glacial epoch) and five New period of higher temperature (Consist of Little OPtimun). THe highest temperature 2~ 3℃ higher tham now during 5000~4000a.B.P., the lowest temperature 3~ 5 lower than now, and the highest sea level 4 ~ 5m higher than now, during 6500~ 6300 a.B.P,. The vegetation shows that in the warmer periods with the diphyllus and deciduous broad-leaved mixed forest or the conifer bread-leaved forest of the subtropical zone, and in the colder poriods with the deciduous broad-leaved forest, the coniferous forest, or the grass land. The futural trend of the environmental changes will can be appeared the drid-temperatural climate and the higher sea level, or the drid-colder climate and the lower sea level, in the case of the man's influence or the natural development. These changes will give rise to the abnormality of catastrophe in the Mid-lower Yangtze River valley region.

关 键 词：环境变迁 冰后期 新冰期 新高温期 长江中下游地区 自然环境 

分 类 号：P942.77[天文地球—自然地理学] P343.1