近2400 a以来达里诺尔湖区域环境演变及其气候响应  

Environment Evolution and Its Response to Climate Change in the Dalai Nur Lake Area in the Last 2 400 Years

作　　者：刘晶晶 张生[1] 李文宝[1] 史小红[1] 徐琼 甄志磊[1] LIU Jing-jing;ZHANG Sheng;LI Wen-bao;SHI Xiao-hong;XU Qiong;ZHEN Zhi-lei(Inner Mongolia Key Laboratory of Water Resources Protection and Utilization,Inner Mongolia Agricultural University,Hohhot 010018.Inner Mongolia,China)

机构地区：[1]内蒙古农业大学水资源保护与利用自治区重点实验室

出　　处：《干旱区研究》2019年第5期1092-1101,共10页Arid Zone Research

基　　金：国家自然科学基金项目(51669021,51469025,51569019);内蒙古自治区自然科学基金项目(2016MS0552)资助

摘　　要：本文以东亚夏季风北部边缘的达里诺尔湖(以下简称"达里湖")为研究对象,通过沉积物岩芯的采集与测试分析,利用正构烷烃及相关指标讨论达里湖区域近2 400 a以来的环境演变及其气候响应。结果显示:达里湖沉积物中正构烷烃的碳数分布为C17~C33。其中,以C25为主峰的单峰形分布约占总样品量的57%;以C19、C25为主峰的双峰形分布约占30%;以C25、C27为主峰的双峰形分布约占13%。正构烷烃的指标参数变化显示,近2 400 a以来达里湖区域环境演变不仅与全球气候事件具有明显的一致性,而且受东亚夏季风降水变化及湖区冷暖变化的影响。将其变化分为6个阶段,其中阶段1、3、5(75 a BP至今、985~600 a BP、2 180~1 550 a BP)为暖湿气候阶段,该阶段湖区有效湿度高,木本植物占据优势,水生植物生长茂盛,湖泊营养状态较好;阶段2、4、6(600~75 a BP、1 550~985 a BP、2 355~2 180 a BP)为冷干气候阶段,该阶段菌藻类繁殖较快,草本植物比例增加,湖泊初级生产力较低。整体上,近2 400 a以来达里湖区域的气候变化由暖湿向冷干转变。In this paper,the Dalai Nur Lake(named DL-1)located in the northern marginal zone of the East Asian summer monsoon was taken as the research object.Through collecting,testing and analyzing the sediment core samples,the environmental evolution and its response to climate change in the Dalai Nur Lake area in the last 2 400 years were discussed using n-alkanes and related indicators.The results showed that the carbon number distribution of n-alkanes in the sediment of Dalai Nur Lake varied in a range of C17-C33.In which the curve of C25 distribution was unimodal and its proportion accounted for 57%of the total samples;the curves of C19 and C25 distribution were bimodal and their proportion accounted for 30%;the curves of C25 and C27 distribution were bimodal and their proportion accounted for 13%.The change of the index parameters of n-alkanes revealed that the environmental evolution in the Dalai Nur Lake region was not only consistent with the global climate events,but also affected by the changes of precipitation in East Asian summer monsoon and of cold-warm events in the lake region over the past 2 400 years.The climate change could be divided into six stages.Stages 1,3 and 5(75 a BP present,985-600 a BP and 2 180-1 550 a BP)were the warm-humid climatic stages.At these stages,the effective humidity in the lake area was high,woody plants were dominant,aquatic plants grew vigorously,and the nutrient status of the lake was fine.Stages 2,4 and 6(600-75 a BP,1 550-985 a BP and 2 355-2 180 a BP)were the cold-dry climatic stages.At these stages,bacterial algal reproduction was fast,the proportion of herbaceous plants increased,and the primary productivity of the lake was lower.Overall,climate change in the Dalai Nur Lake area changed from warmhumid pattern to cold-dry pattern over the past 2 400 years.

关 键 词：生物标志物 正构烷烃 环境演变 全新世 达里诺尔湖 内蒙古 

分 类 号：X52[环境科学与工程—环境工程]