摘要
本文对昆明滇池草2孔四万年以来的沉积物进行孢粉分析,得出4个孢粉组合带,它们是:Ⅰ组合带(ca.47600—11800yr B,P.),以针叶树种为主,总花粉沉积率很低。其中又划分4个亚带。Ⅱ组合带(ca.11800—6900yr B.P.),阔叶植物成分增加和冷杉花粉逐渐消失。Ⅲ组合带(ca.6900—3800yr B.P.),常绿阔叶成分达到最大值,铁杉花粉逐渐消失,总花粉沉积率最高。Ⅳ组合带(3800yr B.P.至今),各类植物花粉沉积率均大大地减少,光面单缝孢增多。植被的变化,反映了气候从凉湿到暖湿而后又趋向温干的过程。
This paper presents results of pollen analysis on sediments of core Cao 2 from Dianchi Lake.Four pollen zones are defined,namely zone I,which is further divided into four sub— zones,zoneⅡ,zoneⅢand zone Ⅳ.Zone Ⅰ(ca.47600—11800 yrs B.P.)is characterized by low land pollen sedimentation rates and constant presence of Abies pollen.In zoneⅡ(ca. 11800—6900 yrs B.P.)broad-leaved tree pollen increases and Abies pollen gradually disap- pears.In zone Ⅲ(ca.6900—3800 yrs B.P.)evergreen broad-leaved-tree pollen and total land pollen influx reach their maximum values while,Tsuga pollen decreases.Zone Ⅳ shows a great decreases in pollen influx of various pollea types and a increase in Monolete psdate spores.In the past 40000 years vegetation in this area trend changes from a dominantion of coniferous tree to an evergreen broad-leaved forest,co-existing or mixing deciduous broad- leaved forest and coniferous forest.In the past 3800 years,due to climate changes and/or human activities,the vegetation cover in this area has been greatly reduced.The above vegeta- tion changes indicate a climate change process from cool and humid,to warm and humid and finally to mild and dry.
基金
国家自然科学基金
关键词
滇池
古植被
气候演变
Dianchi Lake
Late Pleistocene
Holocene
Pollen analysis
