Modern pollen-vegetation relationships and two new pollen-climate indices in the Yarlung Zangbo River basin in southern Tibetan Plateau
Modern pollen-vegetation relationships and two new pollen-climate indices in the Yarlung Zangbo River basin in southern Tibetan Plateau
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DOI：
10.7523/j.issn.2095-6134.2017.06.009
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发表时间：
2017-11
期刊：
影响因子：
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通讯作者：
A. Sun;Dehua Zhang;Ran Dai
中科院分区：
文献类型：
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作者：
A. Sun;Dehua Zhang;Ran Dai
本研究在青藏高原南部雅鲁藏布江流域沿东西向的横断面上沿着采集了70个花粉表面样品。花粉组合和主成分分析结果表明，沿着各植被带具有明显的现代花粉组合特征：1）松林带：松属花粉组合; 2）冷杉-云杉林带：冷杉-松属-云杉属花粉组合; 3）阔叶林/灌丛带：栎-桦-松属花粉组合; 4）高寒草甸带：莎草科-蒿属-菊科花粉组合; 5）高寒草原带：蒿属-莎草科-禾本科花粉组合。我们使用的数据来定义两个新的花粉气候指数，（Pi，Ti），主要花粉类群和亚群之间的比例的基础上。这些指数代表了研究区的年平均降水量（MAP）和年平均温度（MAT），它们密切跟踪整个YLZR流域的降水和温度的区域西-东梯度。我们认为，花粉植被气候指数可能是有用的，为未来的古气候重建化石花粉数据。
This study collected 70 pollen surface samples along an east-west transection in the Yarlung Zangbo River (YLZR) basin in the southern Tibetan Plateau. Pollen assemblage and principle components analysis results show that each vegetation zone along the transection is characterized by distinctive modern pollen assemblages as follows:1) pine forest zone:Pinus pollen assemblage; 2) fir and spruce forest zone:Abies-Pinus-Picea pollen assemblage; 3) broadleaved forest/shrubland zone:Quercus-Betula-Pinus pollen assemblage; 4) alpine meadow zone:Cyperaceae-Artemisia-Compositae pollen assemblage; and 5) alpine steppe zone:Artemisia-Cyperaceae-Poaceae pollen assemblage. We use the data to define two new pollen-climate indices, (Pi, Ti), based on the ratio between major pollen taxon groups and subgroups. The indices represent the mean annual precipitation (MAP) and mean annual temperature (MAT) of the study area, and they closely track the regional west-east gradients in precipitation and temperature across the YLZR basin. We suggest that the pollen-vegetation-climate indices may be useful for future palaeoclimatic reconstructions using fossil pollen data.