长白山区湿地表土植硅体特征及其环境意义

Phytolith characteristics and their significance of environment in surface soils from wetlands of Changbai Shan area

湿地在全球环境变化中扮演着十分重要的角色,湿地表土中的植硅体分析是恢复第四纪古环境的重要途径。文中选取长白山区的桦南到哈尼一线的6处湿地表土,并采用PCA和CA分析植硅体组合的环境指示意义,结果显示:温度因子是造成长白山不同湿地表土植硅体组合差异的第1环境因子,且植硅体的种类和含量与采样点上覆植被、湿度与海拔等环境条件都存在相关性。结合方差分析和植硅体大小变化趋势分析曲线可以看出,不同表土中符合方差分析条件的植硅体类型的大小随着温度的升高而增大。总体来看,长白山区6处湿地中,植硅体类型基本相同,但温暖指数和植硅体的大小差异较显著,说明植硅体大小及其组合对温度都有较敏感的响应。

Wetlands play an important role in the global environmental change, and phytolith analy- sis in surface soil of wetlands is a basis for reconstructing the palaeoenvironment in the Quaternary. In this paper, surface soil phytoliths were analyzed in six wetlands from Huanan to Hani in Changbai Shan area. The results show that the phytolith assemblages in all wetlands surface soil samples except for Shalan are similar. Elongate, crenate, rondel and point-shaped phytoliths are dominant, which reveals the cold cli- mate. PCA and cluster analysis are used to find the environmental significance of the phytoliths assembla- ges in different wetlands surface soils. The results indicate that temperature is the chief factor to control the otherness of phytoliths assemblages in wetlands in Changbai Shan area, at the same time, the types and percentages of phytoliths are closely related to the plants, humidity and elevation in the sample sites. Combining difference analysis with the change trend analysis in phytolith dimension, we can find that the width and length of bicrenate, polycrenate and crenate sinuate as well as the length of elongate psilate, the length of ridge and the height in rondel hipped and width of the point-shaped phytoliths exist significant difference and increase with the temperature. In sum, the phytolith morphotypes in all the sites are simi- lar, but differences in the warm index and the size of the phytoliths are obvious. The result reveals that the phytolith assemblages and the size are sensitive to temperature change.