末次冰盛期以来东北地区古植被定量重建及其气候响应  

QUANTITATIVE RECONSTRUCTION OF PALEOVEGETATION HISTORY IN NORTHEAST CHINA AND ITS RESPONSE TO CLIMATE CHANGE SINCE THE LAST GLACIAL MAXIMUM

作　　者：张瑞[1] 李琴[1] 勇心意 于梦晴 ZHANG Rui;LI Qin;YONG Xinyi;YU Mengqing(School of Geography,Liaoning Normal University,Dalian 116029,Liaoning)

机构地区：[1]辽宁师范大学地理科学学院,辽宁大连116029

出　　处：《第四纪研究》2024年第3期805-822,共18页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42177423);辽宁省“兴辽英才计划”项目(批准号:XLYC2203022)共同资助。

摘　　要：植被是陆地生态系统的主体,其演化对全球气候变化及碳循环有着至关重要的影响。重建过去典型增温过程中植被的变化,是评估全球变暖背景下植被响应的关键之一。末次冰盛期(LGM)是末次冰期中距今最近的气候最冷、冰川规模最大的时段。LGM以来,气候经历了从末次冰盛期到全新世的逐渐增温和后续降温过程。本研究综合公开发表的东北地区的69条孢粉序列,通过生物群区化方法定量重建了LGM以来其植被分布格局变化。结果表明,21~12 ka B.P.,森林仅分布在东部边缘山地,该时期森林类型点位比例最低,仅25%,研究区大面积被草原和荒漠占据;12~9 ka B.P.,森林向西、北方向扩张,草原被迫向内蒙古高原地区迁移,森林-草原分界线逐渐向西移动;9~5 ka B.P.,森林成为主要植被类型,在东北地区广泛分布,森林点位比例在6 ka B.P.达到最大值,约65%以上。温带落叶林分布范围与现代相比,最北界向北扩张大约7°~8°。草原仅分布在松嫩平原东部和内蒙古高原北部。全新世大暖期(6±0.5 ka 14C),森林-草原分界线大致分布在现代300 mm年等降水量线附近;5 ka B.P.以来,草原再次扩张。森林向东部边缘山地迁移。森林-草原分界线向东迁移。此外,温带落叶林出现的海拔变化显示,LGM以来其逐渐上升至全新世早中期开始下降,与全球温度变化类似。进一步分析表明,LGM以来,降水或有效湿度可能是控制东北地区森林整体比例变化的主要驱动因素。此外,5 ka B.P.以来,人类活动对植被分布格局的影响是不可忽视的。Vegetation is a major component of terrestrial ecosystems,and its evolution plays a critical role in global climate change and the biogeochemical cycles.Large-scale palaeovegetation reconstruction during warming plays a critical role in improving our understanding of the response of vegetation to climate change and in reducing the uncertainty in predictions of vegetation change under global warming scenarios.The interval since the Last Glacial Maximum(LGM,about 21 ka B.P.)is the most recent glacial-interglacial cycle,during which global temperatures has experienced an overall warming trend from the LGM to the Holocene Thermal Maximum(about 10~6 ka B.P.),which was followed by a cooling trend.In addition,atmospheric CO_(2) has increased significantly since the LGM.Here,we present a quantitative large-scale vegetation reconstructions since the LGM in Northeast China,including Heilongjiang,Jilin,Liaoning provinces,and the northeast part of Inner Mongolia,using 69 selected fossil pollen records analyzed using the biomization method.The results show that from 21 ka to 12 ka(1 ka=1000 cal.a B.P.),forests were limited to the eastern marginal mountains,and the percentage of forested sites reached a minimum,only 25%,whereas steppe and deserts dominating most regions.From 12 ka to 9 ka,forest expanded northwestwards,and steppe migrated to the Inner Mongolian Plateau.The forest-steppe boundary gradually shifted westward.From 9 ka to 5 ka,forest flourished and dominated in Northeast China,the percentage increased with the maximum at 6 ka B.P.,(about 65%more).Temperate deciduous forest(TEDE)shifted northwards 7°~8°in latitude,respectively,relative to today.Steppes were restricted to the east of the Songnen Plain and north of the Inner Mongolian Plateau.The forest-steppe boundary retreated northwestward approximately to the location of the modern 300 mm isohyet during the Holocene warm period(6±0.5 ka 14C).Since 5 ka,steppe gradually shifted eastwards at the expense of the forest,which caused the forest-steppe boundary move

关 键 词：末次冰盛期 生物群区化 植被重建 孢粉 中国东北地区 

分 类 号：P534.631[天文地球—第四纪地质学] Q944.571[天文地球—古生物学与地层学] Q948.112.4[天文地球—地质学]