柴达木盆地可鲁克湖沉积物表层花粉散布规律及其对区域植被的指示意义

Surface Pollen Distribution and Ecological Significancein Hurleg Lake，Qaidam Basin

中文关键词:  花粉  可鲁克湖  青藏高原  湖泊沉积物  柴达木盆地

英文关键词:Pollen  HurlegLake  Qinghai-XizangPlateau  Lacustrinesediment  QaidamBasin

中文摘要:

      可鲁克湖是柴达木盆地东部荒漠区重要的生态屏障，对全球气候变化响应十分敏感。利用沉积物化石花粉重建湖泊生态系统演变历史及其对全球气候变化响应过程和机制的分析是当前重要的研究方向，本研究系统采集了可鲁克湖沉积物表层样品开展花粉分析。研究结果显示，花粉组合以藜科、禾本科、蒿属、莎草科为主。花粉总浓度在湖泊沉积中心及偏西南区域显著偏高，其中藜科、莎草科、蒿属、白刺属、麻黄属、紫菀属花粉与总浓度变化特征较为一致，而禾本科花粉在湖泊东南部显著富集。湖泊沉积物中的藜科和蒿属花粉较好地指示了柴达木盆地东部灌木 -矮灌木荒漠和荒漠草原整体植被特征，而禾本科和莎草科花粉主要指示湖岸周边隐域性沼泽和河滩草甸植被群落；白刺属花粉对湖泊北岸一级阶地上的白刺群落发育和湖面变化具有较好的指示意义，谷物类禾本科和十字花科花粉能较为灵敏地反映湖泊附近的农耕活动，桦木属和云杉属花粉则主要由风力和河流远距离输入。研究揭示了可鲁克湖水深、水动力条件、湖岸周围植被群落分布以及风力作用是影响花粉散布和沉积的重要影响因素，此项研究也为青藏高原湖泊沉积物花粉组合的精确解译提供了重要数据资料和分析依据。

英文摘要:

      Hurleg Lake is ac riticale cological barrier located in thedesert region of the eastern Qaidam Basin， which is sensitivity to global climate change. The study of modern pollen processes in lake sediments is a prerequisiteforreconstructingtheevolutionaryhistoryoflakeecosystemsandtheirresponsestoenvironmental change. Here，we systematically collected surface sediment samples from Hurleg Lake and conducted pollen analysis，revealing that the pollen assemblages were dominated by Chenopodiaceae，Poaceae， Artemisia，with a notably higher concentration in the sedimentary center of the lake and the southwestern region. Chenopodiaceae and Artemisia pollens were identified as important indicators of the shrub-dwarf shrub desert and desert steppe vegetation in the eastern Qaidam Basin，while Poaceae and Cyperaceae predominantly reflected the azonal marshes and river beach meadows around the lakeshore. Furthermore， Nitraria pollen was found to be a useful indicator of the development of the Nitraria community and lake levelfluctuation on the firstterrace in the northern part ofthe lake bank. Cerealia Poaceae andBrassicaceae pollens were identified as sensitive indicators offarming activities around the lake，while Betula and Picea pollens were primarily transported by wind. It is worth noting that pollen distribution and deposition is significantly influenced by factors such as water depth，hydrodynamic conditions，vegetation community distributionaroundthelake，and windaction.Our study provides important modern process data and a theo-retical basis for the accurate interpretation of pollen assemblages in lake sediments of the Qinghai-Xizang Plateau，contributing to our understanding of vegetation and environmental changes in the Qaidam Basin.