Pollen analysis of sediments from the foothill of the Purple Mountain in Nanjing

Based on pollen analysis of 17 samples of surface lake sediments from Xuanwu Lake and Qianhu Lake from the foothill of the Purple Moutain in Nanjing, pollen assemblages are established to reveal the relationship between surface pollen flora as well as modern vegetation and to provide a modern reference for Quaternary pollen analysis of lacustrine sediments. The results show that apart from abundant human-induced woody taxa, Pinus and Quercus are the dominant elements in the pollen assemblages, and other important pollen taxa such as Liquidambar, Castanea?Castanopsis?Lithocarpus, Anacardiaceae occur frequently. The pollen spectrum generally indicates the coniferous and mixed evergreen-deciduous broad-leaved forest in the surrounding mountains and hills, consistent with the present vegetation of northern subtropical forest. In addition, herbs such as Poaceae and Artemisia and lake wetland plants such as Hydrocharis and Cyepraceae are abundant. The dominant types of trees from different samples in Xuanwu Lake and Qianhu Lake are highly consistent; each sample is ather stable in contents; and both are little affected by sampling location. By comparing with existing modern pollen data of topsoil in forests in Nanjing area, we found that the pollen assemblages of the surface lake sediments are characterized by stable percentages of dominant taxa with little influences of local habitats, suggesting their advantages of reflecting regional vegetation. In order to improve the representativeness and reliability of the relationship between regional vegetation and pollen assemblages, this paper highly suggests that surface lake sediments should be preferred to use for pollen analysis in Quaternary pollen interpretation. This paper yields new data and provides necessary modern basis for Quaternary palynological investigation in terms of pollen-vegetation relationship in the lower reaches of the Yangtze River, especially in Nanjing area.

Project Supported:

Clc Number: