| 云南鹤庆古湖晚更新世的孢粉记录及其古气候学意义 |
| |
| 引用本文： | 羊向东,王苏民,童国榜,吴敬禄,蒋雪中.云南鹤庆古湖晚更新世的孢粉记录及其古气候学意义[J].第四纪研究,1998,18(4):335-343. |
| |
| 作者姓名： | 羊向东 王苏民 童国榜 吴敬禄 蒋雪中 |
| |
| 作者单位： | [1]中国科学院南京地理与湖泊研究怕湖泊沉积与环境开放实 [2]地质矿产部水文地质工程地质 |
| |
| 基金项目： | 中国科学院重大项目!KZ951-Al-402-04，国家自然科学基金!49572131 |
| |
| 摘 要： | 本文通过鹤庆古湖沉积物的孢粉记录对该区晚更新世的古植被和古气候进行了恢复。该区末次间冰期和末次冰期内部气候波动性特点与深海氧同位素记录有着较好的可比性，反映在全球变化的背景上，气候的不稳定性同样在本区有明显的响应。而且不同季风区气候资料对比也表明，本区冷湿和暖干的气候组合具有明显的区域特征，末次冰期该区夏季锋面降水增多，而间冰期则与之相反。造成这种区域环境效应的原因，与西南季风区大气环流的复杂性、云贵高原的地貌部位以及由青藏高原地表反照率引起的热力学和动力学过程有关。
|
| 关 键 词： | 鹤庆古湖 孢粉记录 气候不稳定性 古季风气候 |
| 收稿时间： | 1998-08-05 |
| 修稿时间： | 1998-08-18 |
THE LATE PLEISTOCENE POLLEN RECORD IN THE LAKE SEDIMENTS FROM ANCIENT HEQING LAKE AND ITS SIGNIFICANCE FOR PALAEOCLIMATE |
| |
| Yang Xiangdong, Wang Sumin,Wu Jinglu, Jiang Xuezhong.THE LATE PLEISTOCENE POLLEN RECORD IN THE LAKE SEDIMENTS FROM ANCIENT HEQING LAKE AND ITS SIGNIFICANCE FOR PALAEOCLIMATE[J].Quaternary Sciences,1998,18(4):335-343. |
| |
| Authors: | Yang Xiangdong Wang Sumin Wu Jinglu Jiang Xuezhong |
| |
| Institution: | 1. Lake Sedimentation and Environment Laboratory, Nanjing Institute of Geography and Limnology Chinese Academy of Sciences, Nanjing 210008;
2. Instrtute of Hydrogeology and Engineering Geology, Ministry of Geology and Mineral Research, Zhengding 050803 |
| |
| Abstract: | The palaeo-vegetation succession and palaeoclimate of Late Pleistocene have been feconstructed from the pollen record of the lake sediments from ancient Heqing Lake.This region sits at the edge of northwestern subtropical high pressure, dominated by the south branch of westlie in winter and by the warm-wet airmass from Bengal Bay in summer. As a result, this area is characterized by cool-dry climate in winter,temperate-wet climate in summer, and small annual temperature deviation. The Heqing core has a depth of 168m, located in the center of the basin. A total 362 samples from 39.0～3.0m of the core are analyzed, and the time interval for each sample is 359a.Total 5 large change stages have been divided for the pollen record of the past 0.136 MaB. P.: （1） The pollen concentration of 0.136～0.130 MaB. P. was low dominated by Picea and Pinus, suggesting the climate was cool and humid. （2） The climate in 0.130 MaB.P. ～73 400 aB.P. was warm and dry, and the mixed coniferous and deciduous broadleaved forest was developed, dominated by Pinus and Quercus,with two cold-wet pulses of increasing percentage of Picea and Tsuga. （3） In 73 400～44 200 aB.P. the coniferous and broadleaved forest containing dark coniferous trees grew, suggesting a temperature decent and increased humidity, in which the pine forest was developed and the climate turned warm and dry in the middle part. （4） The pine forest alternated with sclerophyllous oaks forest in 44 200 ～ 27 200aB. P.,indicating the climate has experienced from tempefate-drier to cool-wetter, then to temperate-drier. （5） The mixed mountainous coniferous and broadleaved forest dominated by Tsuga, Picea and sclerophyllous oaks appeared in 27 200～15 500aB.P.,showing the climate was cold and wet with a warm-dry fluctuation in Last Glaciation Maximum. The warm species increased from 15 500aB.P. and the temperature beganto rise in the Late Glaciation.The climate in this region have experienced a whole climatic cycle from Last Interglaciation to Glaciation, with the climate fluctuation of different time scale. The result could be compared well with the oxygen isotope record from the deep sea.Indiating that the climate of this area in Late Pleistocene is clearly controlled by the global climate change, and there do exist some dynamic linkage from the behavior of the climatic instability which has been shown in deep sea and in Greenland ice core.The comparative study of the climate data from different monsoon regions show that the increased humidity associated well with decreased temperature. This kind of regional climate features could be resulted from the complexity of atmospheric circulation in the southwest monsoon are4 the plateau geomorphology and the change in the albedo of Qinghai-Xizang Plateau. In LGM, the winter hardiness and hydrophilous cohiferous species and deciduous broadleaved species increased,suggesting the distinct descent of temperature in winter and increase of front precipitaion in summer. It may suggest that the weakening or regression of the south branch of westlie and the enhancement of the albedo of Qnghai-Xizang Plateau and a stable cold high pressure can give rise to the intrusion of the cold airmass from the north, even in the summer season. The frequent intrusion of the cold airmass matched with the penetration of southwest monsoon have led to large scale summer monsoon front precipitation. In Last Interglaciation, the increase of the percentage of Pinus,Quercus imply that the winter temperature was not low and the summer is warm and dry, when the strengthened westlie and the obstruction of the Plateau has protected the stUdy region from cold airmass in winter. In addition, in thermoclimathem the warm pool effect of Qinghai-Xizang Plateau has caused the further strengthening and expand to the northwest of the SAT high pressure, correspondingly, the precipitatin became less than that of today. |
| |
| Keywords: | ancient Heqing Lake pollen record climatic change palaeomonsoon |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《第四纪研究》浏览原始摘要信息 |
| 点击此处可从《第四纪研究》下载免费的PDF全文 |
|
