Grain-size characteristics and environmental significance of Sphagnum Mire at Qizimei Mountains in Western Hubei Province
LI Ze1,2， LIU Tao1,2,3， LI Tingting1,2,3， WANG Zhengxiang1,2,3， LEI Yun4， PENG Zonglin5
1.Faculty of Resources and Environmental Sciences， Hubei University， Wuhan 430062；2.Hubei Key Laboratory of Regional Development and Environmental Response， Wuhan 430062；3.Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources， Wuhan 430062；4.School of Life Sciences， Central China Normal University， Wuhan 430079；5.Hubei Qizimeishan National Nature Reserve， Xuanen， Hubei 445500
摘要以鄂西七姊妹山泥炭藓湿地QZMS钻孔沉积物为研究对象，通过AMS14C测年、岩性特征与沉积物粒度综合分析，探讨了鄂西南山地13 000 cal. a BP以来的沉积环境变迁.研究结果显示：QZMS钻孔沉积物粒度组成主要以细粉砂和中粉砂为主，频率分布曲线均为单峰分布，由下至上，峰度由宽到窄，偏度从近于对称到正偏，揭示了搬运动力和沉积环境的演变过程；综合分析结果表明研究区沉积环境演化可分为4个阶段：1) 12.9～11.6 cal. ka BP，气候波动频率高，但幅度较小，水动力条件相对较弱；2) 11.6～10.2 cal. ka BP为晚更新世向全新世的过渡阶段，水动力条件持续较弱，环境相对稳定；3) 10.2～7.7 cal. ka BP早全新世，气候变得暖湿，水动力条件较前一阶段有所增强，泥炭藓湿地开始形成；4) 7.7～2.0 cal. ka BP气候暖湿，水动力条件达到最强，峰度和偏度波动频率低，但幅度增大，为沼泽湿地环境.研究表明七姊妹山泥炭藓湿地沉积物的粒度粗细与区域内水文条件和物源的变化密切相关，借助粒度组成和参数特征，可反演该区域的沉积环境演变，揭示泥炭藓湿地发育形成的过程，为该地区泥炭藓湿地的保护和气候环境变化研究提供科学参考.
Abstract：Taking the QZMS core sediments of Sphagnum wetlands at Qizimei Mountains in Western Hubei Province as the research object， the climate change of southwest mountainous region of Hubei since 13 000 cal. a BP is discussed through the comprehensive analysis of AMS14C dating， lithologic characteristics and grain-size of the sediments. The research has shown that the grain composition of QZMS core sediments are mainly composed of fine silt and silt. The frequency distribution curves are unimodal， and from bottom to top， the kurtosis is from wide to narrow with the skewness from nearly symmetric to positive-skewed， which reflected the evolution of handing dynamics and sedimentary environment. The synthetical analysis results indicate that the evolution of sedimentary environment in the study area can be divided into four stages： 1) 12.9～11.6 cal. ka BP， the climate had a high frequency of wave but low amplitude， and the hydrodynamic condition was relatively weak. 2) 11.6～10.2 cal. ka BP， the transition stage of late Pleistocene to Holocene， the hydrodynamic condition stayed weak and the environment was stable. 3) 10.2～7.7 cal. ka BP， compared with the previous stage， the temperature was gradually increased， and the hydrodynamic condition became stronger， the climate was becoming warm and wet. 4) 7.7～2.0 cal. ka BP， the climate was warm and wet as well as relatively stable. The hydrodynamic condition became the strongest with low fluctuation frequency while high amplitude of the kurtosis and skewness. The result means that the grain-size of Sphagnum wetlands at Qizimei Mountains was closely related to the hydrodynamic condition and the change of the source. By virtue of the grain-size composition and parameters distribution characteristics， the evolution of sedimentary environment is able to be rebuilt， revealing the developmental process of the Sphagnum wetlands and providing scientific reference for study on the protection of wetlands and climate change in this region.
李 泽,刘 韬,李亭亭,汪正祥,雷 耘,彭宗林. 鄂西七姊妹山泥炭藓湿地沉积物粒度特征及其环境意义探讨[J]. 华中师范大学学报(自然科学版), 2017, 51(5): 680-689.
LI Ze,LIU Tao,LI Tingting,WANG Zhengxiang,LEI Yun,PENG Zonglin. Grain-size characteristics and environmental significance of Sphagnum Mire at Qizimei Mountains in Western Hubei Province. journal1, 2017, 51(5): 680-689.
2017, Vol. 51 
