Surface pollen assemblages from different sedimentary environments in the Yinchuan Basin, North China, and their significance for stratigraphic pollen records
Surface pollen assemblages from different sedimentary environments in the Yinchuan Basin, North China, and their significance for stratigraphic pollen records
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DOI：
10.1016/j.quaint.2021.02.015
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发表时间：
2021-02
影响因子：
2.2
通讯作者：
Xinling Li;Mingjian Wei;Shengrui Zhang;M. Cai;Junping Wang
中科院分区：
文献类型：
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作者：
Xinling Li;Mingjian Wei;Shengrui Zhang;M. Cai;Junping Wang
了解花粉的来源、分布和运移机制对于利用化石花粉资料重建植被和气候具有重要意义。对银川盆地不同地貌单元（山地、中央盆地和河流带）的28个地表样品进行了现代花粉组合研究。目的是比较不同沉积环境的花粉组合特征，并确定花粉源区和迁移机制的差异。结果表明：（1）山地和皮埃蒙特冲积扇环境的花粉组合以乔木花粉为主，乔木花粉含量随海拔的降低而降低。皮埃蒙特冲积扇环境中的花粉主要由地表径流搬运，花粉组合兼有山地和当地植被的特点。(2)中央盆地的花粉组合主要由地带性荒漠草原植被产生的花粉。(3)从河流地带的花粉组合占主导地位的长距离的组成部分，从流域的上部。结果表明，银川盆地沉积花粉中乔木花粉成分主要反映了周边山地植被的变化，草本花粉成分反映了荒漠草原植被的变化，而长距离河流搬运花粉成分则反映了上游流域植被的变化。
Understanding the sources areas and transport mechanisms of pollen grains is important for reconstructing vegetation and climate from fossil pollen data. We studied the modern pollen assemblages of 28 surface samples from different geomorphic units (mountains, the central basin, and the riverine zone) in the Yinchuan Basin in China. Our aim was to compare the characteristics of the pollen assemblages from the different sedimentary environments and to determine the differences in pollen source areas and transport mechanisms. The results show that: (1) The pollen assemblages from the mountain and piedmont alluvial fan environments were dominated by trees, with the tree pollen content decreasing with decreasing altitude. The pollen in the piedmont alluvial fan environment was mainly transported by surface runoff, and assemblage combines the characteristics of both the mountain and the local vegetation. (2) The pollen assemblages from the central basin were dominated by pollen produced by the zonal desert-steppe vegetation. (3) The pollen assemblages from the riverine zone were dominated by a long-distance component from within the upper part of the drainage area. The results suggest that in sedimentary pollen records from the Yinchuan Basin, the arboreal pollen component primarily reflects vegetation changes within the surrounding mountains; the herbaceous pollen component is an indicator of changes in desert-steppe vegetation; and the long-distance fluvially-transported pollen component reflects vegetation changes in the upstream drainage area.