猪野泽全新世湖泊沉积地层孢粉组合对比及孢粉传播意义

A COMPARATIVE STUDY OF POLLEN ASSEMBLAGES IN HOLOCENE LACUSTRINE SEDIMENTS OF ZHUYE LAKE AND ITS PALEOCLIMATOLOGICAL SIGNIFICANCE FOR POLLEN TRANSMISSION

湖泊沉积物中孢粉组合因受花粉传播过程以及湖泊水动力条件影响,湖盆不同位置沉积物中孢粉组合存在差异。已有研究表明湖泊表层沉积物中孢粉组合存在差异,但是就古气候研究来讲,湖盆不同位置沉积地层中的孢粉组合对比更有益于古环境重建。猪野泽是近年来全新世研究的热点区域,该湖盆现有多个剖面分布于湖盆不同位置,为同一湖盆不同位置地层孢粉组合对比提供了条件,而其他湖泊因受钻孔或剖面数量及位置的限制很难展开上述研究。研究在原有SJC、QTH02和QTL03孢粉剖面的基础上,增加了SKJ、JTL剖面全新世孢粉组合结果,来探讨全新世千年尺度上湖盆内部孢粉传播动力学特性。SJC剖面全新世孢粉组合反映流域植被变化;QTL03、QTH02剖面沉积环境相对稳定,但孢粉组合仍不可避免地受到流域性花粉的影响;SKJ、JTL剖面远离入湖区,其孢粉组合反映全新世湖泊周围植被特征。因此,在解释千年尺度孢粉组合的古环境意义时,应充分考虑湖盆内部花粉的再分配和传播过程。

Affected by propagation process and hydrodynamic conditions, the pollen assemblages in the di- verse parts of a lake surface are different, as previous studies show. Therefore, comparison of the pollen assemblages in lake sediments, which come from different parts of the lake basin, will be useful to the re- construction of the paleoenvironmental pattern and paleoclimate studies. So far, some sections located in different parts of the Zhuye Lake have become a hot spot for comparative study of pollen assemblages on paleoclimate. This paper not only focuses on sections SJC.QTH02 and QTL03, but also on sections SKJ and JTL for Holocene pollen assemblages. We also discussed in this paper the transmission dynamics and characteristics of pollen in a millennial scale. It is found that the pollen assemblages of section SJC can re flect basin-wide changes in vegetation in Holocene; the sedimentary environment of sections QTL03 and QTH02, however, is relatively stable, but pollen assemblages will still be affected by basin-wide pollen; pollen assemblages in the sections of SKJ and JTL reflect vegetation around the lake in Holocene. As the conclusion, we should carefully consider the redistribution and propagation of pollen while pollen assembla- ges are adopted for environmental interpretation in a millennial scale.