西天山北坡过去千年以来的植被与气候变化  

VEGETATION AND CLIMATE CHANGE ON THE NORTHERN SLOPE OF WEST TIANSHAN MOUNTAIN IN THE PAST MILLENNIUM

作　　者：黄健 姚付龙 HUANG Jian;YAO Fu Long(College of Biological and Geographical Sciences Institute of Resource and Ecology,Yili Normal University,Yining835000)

机构地区：[1]伊犁师范大学生物与地理科学学院资源与生态研究所,新疆伊宁8835000

出　　处：《地层学杂志》2022年第3期306-315,共10页Journal of Stratigraphy

基　　金：国家自然科学基金(41961013);自治区自然科学基金(2019D01C338)共同资助。

摘　　要：西天山北坡地处西风带,对气候变化响应敏感。因缺乏高分辨率古气候记录,学界对该地区千年以来气候变化过程的认识尚不清晰,中世纪暖期与小冰期的水热组合模式争议较大。为提升对上述问题的认识,本文以西天山北坡昭苏盆地千年以来的泥炭沉积物为研究材料,通过对其精准定年及高分辨率孢粉研究,重建了该区域千年以来的植被与气候变化过程,结果表明:(1)千年以来西天山北坡气候变化过程依次为暖干、暖湿、冷湿。1046—1146AD期间,桦木属含量处于峰值,A/C值较低,气候以暖干为主;1146—1288AD为中世纪暖期,云杉属含量与A/C值开始增加, PCA axis 2得分偏负,气候转向暖湿;1288—1476 AD为中世纪暖期向小冰期过渡时期,桦木属含量减少, PCA axis 2得分出现正值,气温开始降低,环境向冷湿转变;1476—1606 AD为小冰期阶段, A/C值与喜冷的云杉属含量均达到峰值,气候向冷湿进一步发展。(2)西天山北坡千年以来气候变化过程并不稳定,气候波动频繁,湿度持续增加,泥炭沉积物记录了以暖湿为主的中世纪暖期及冷湿的小冰期,这可能是由太阳辐射强度减弱、西风环流加强及温室气体含量增加导致。The norther slope of West Tianshan Mountain is located in the westerly zone and sensitive to climate change. Due to the lack of high-resolution paleoclimate records, the understanding of the climate changes in the region for thousands of years is not clear, and hydrothermal combination mode of the Medieval Warm Period and the Little Ice Period are controversial. In order to improve the understanding of the above problems, this paper took the peat sediments of Zhaosu basin on the north slope of West Tianshan Mountain as the research material, and reconstructed the process of vegetation and climate change in the region since the Millennium through accurate dating and high-resolution palynological analysis. The results show that:(1) the climate on the northern slope of West Tianshan Mountain has changed from warm dry through warm wet to cold wet since the millennium. During 1046-1146 AD, the content of Betula was at the peak, the A/C value was low, and the climate was mainly warm and dry;The period of 1146-1288 AD was a warm period in the Medieval Warm Period, the Picea and A/C values began to increase, PCA axis 2 score is negative, and the climate turned to warm and humid;1288-1476 AD was the transitional period from the Medieval Warm Period to the Little Ice Period. The content of Betula decreased, the PCA axis 2 score was positive, the temperature began to decrease, and the environment changed to cold and wet;1476-1606 AD was the stage of Little Ice Age. Both A/C value and the content of Picea reaches the peak, suggesting the climate developed further to cold and wet.(2) The climate change process on the north slope of West Tianshan Mountain has been unstable for thousands of years, with frequent climate fluctuations and continuous increase of humidity. Peat sediments record the Medieval Warm Period dominated by warm wet and the Little Ice Period is characterized by cold wet, which may be due to the weakening of solar radiation intensity, strengthening of westerly circulation and increase of greenhouse gas conten

关 键 词：泥炭 过去千年 孢粉 中世纪暖期 小冰期 天山 

分 类 号：P534.63[天文地球—第四纪地质学]