罗文磊^1,,
常洁¹,
孙伟伟¹,
曹艳敏²,
宁栋梁¹,
张恩楼^1,,
1. 中国科学院南京地理与湖泊研究所, 湖泊与环境国家重点实验室, 江苏 南京 210008
2. 中南民族大学资源与环境学院, 湖北 武汉 430074

基金项目: 国家重点研究发展计划项目"全球变化及应对"（批准号：2016YFA0600502）、科技基础性工作专项项目（批准号：2014FY110400）和国家自然科学基金项目（批准号：41572337和41702183）共同资助


详细信息

作者简介: 罗文磊, 男, 27岁, 工程师, 自然地理学专业, E-mail:wlluo@niglas.ac.cn

通讯作者: 张恩楼, E-mail:elzhang@niglas.ac.cn

中图分类号: P532;Q913;P941.78

收稿日期:2018-03-22
修回日期:2018-05-18
刊出日期:2018-07-30

A 8000-year climate and environmental record inferred from subfossil chironomids from Chenghai Lake, Southwestern China

Luo Wenlei^1,,
Chang Jie¹,
Sun Weiwei¹,
Cao Yanmin²,
Ning Dongliang¹,
Zhang Enlou^1,,
1. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, Jiangsu
2. College of Resources and Environmental Science, South-Central University for Nationalities, Wuhan 430074, Hubei


More Information

Corresponding author: Zhang Enlou,E-mail:elzhang@niglas.ac.cn

MSC: P532;Q913;P941.78

--> Received Date: 22 March 2018
Revised Date: 18 May 2018
Publish Date: 30 July 2018


摘要
摘要:季风气候是影响地区古环境变化的主要因素。文章通过程海长556cm岩芯的沉积摇蚊亚化石、粒度、TOC、TN和TOC/TN记录，探讨了季风气候影响下程海地区约7660cal.a B.P.以来的降水变化情况。结果表明，沉积物中摇蚊属种以Procladius Skuse、Chironomus plumosus、Tanytarsus mendax和Microchironomus tener为主。约7660~2800cal.a B.P.时期流域受印度季风影响强烈，气候暖湿、降水量大，湖泊生产力水平较高；约2800cal.a B.P.以来程海流域降水量逐渐减少，湖泊生产力水平降低。Procladius Skuse与T.mendax的组合关系反映了程海在约6850~6500cal.a B.P.、约5500~5000cal.a B.P.、约4150~3700cal.a B.P.、约2800~2300cal.a B.P.和约1400~1100cal.a B.P.这5个时期由于印度季风减弱，发生了短暂性的干旱事件，研究表明季风因素驱动下的程海摇蚊亚化石组合主要受流域降水侵蚀因素的影响。
关键词: 程海/
摇蚊/
湖泊沉积/
古降水/
气候变化

Abstract:A robust, well-dated and good resolution record of changes in the Asian summer monsoon is crucial for understanding the potential forcing factors and their environmental effects. Lake Chenghai(26°27'~26°38'N, 100°38'~100°41'E) is located on the Yunnan Plateau, about 46km southeast of Yongsheng County in Yunnan Province. The lake surface area is about 77km², the maximum depth is about 35m, with a mean of 20m, and the area of the catchment is 318km². The lake basin is surrounded on three sides by mountains, and the south is relatively low and flat. This lake is hydrologically recharged by precipitation, surface runoff, and groundwater at present. Mean annual precipitation is about 740mm, with more than 90% falling in the wet season from June to September, reflecting the influence of the Indian summer monsoon(ISM). In this study, we analysed the subfossil chironomids, grain size distribution, total organic carbon(TOC), total nitrogen(TN) and C/N in a 556-cm long sediment core(26°33'29.4″N, 100°39'6.7″E) retrieved from Lake Chenghai in the Yunnan Plateau, China. Several ordination analyses were performed using the CANOCO version 4.5 program package to explore the changes in subfossil chironomid species assemblages over the past in Chenghai Lake and to determine which variable (s) (grain size fraction < 4μm, Tsuga(%), TOC, TN) explained a significant proportion of the temporal variation in the chironomid assemblages. The results provide a continuous 7660-year precipitation record of the Indian summer monsoon(ISM). Chironomids assemblages are dominated by Procladius Skuse, Chironomus plumosus, Tanytarsus mendax and Microchironomus tener. The results indicate that from 7660cal.a B.P. precipitation around Lake Chenghai catchment gradually increased until 2800cal.a B.P., and then decreased in the last 2800 years. In addition, at least five centennial-scale droughts occurred at about 6850~6500cal.a B.P., 5500~5000cal.a B.P., 4150~3700cal.a B.P., 2800~2300cal.a B.P., and 1400~1100cal.a B.P. Our findings suggest that subfossil chironomids is primarily controlled by variations in precipitation through the catchment erosion process on a centennial time scale.
Key words:Lake Chenghai/
chironomids/
lake sediment/
paleo-precipitation/
climatic variation



PDF全文下载地址:

http://www.dsjyj.com.cn/data/article/export-pdf?id=dsjyj_11503