江苏宜兴龙池山现代植被表土孢粉的初步研究

PRELIMINARY STUDY ON SURFACE POLLEN FLORA IN THE LONGCHI MOUNTAIN NATURE RESERVE,YIXING,JIANGSU PROVINCE

江苏宜兴龙池山森林自然保护区表土花粉分析结果表明,表土孢粉植物群主要以栎属(Quercus)、松属(Pinus)、青冈属(Cyclobalanopsis)、栲属(Castanopsis)/柯属(Lithocarpus)、栗属(Castanea)占优势的木本植物组成,混生有枫香属(Liquidambar)、杨梅属(Myrica)、冬青属(Ilex)、女贞属(Ligustrum)、紫树属(Nyssa)、盐肤木属(Rhus)、黄连木属(Pistacia)等亚热带常见植物类型。研究区不同海拔高度的表土孢粉组合特征基本反映了当地现今的植物构成、植被面貌及其垂直分布规律。结合长江三角洲及其周边地区其他代表性表土花粉资料,首次提出以常绿阔叶木本植物与落叶阔叶木本植物含量之比(E/D),并结合重要优势、标志木本植物科属,初步识别和确立各地带性森林植被的表土花粉指标,为这一地区开展第四纪古植被和古气候等孢粉研究提供参考性依据。

This paper analyzes the pollen and spores of eight moss samples collected from the Longchi Mountain Nature Reserve, Yixing, Jiangsu Province. The surface pollen flora is dominated by Quercus, Pinus, Cyclobalanopsis, Castanopsis/ Lithocarpus and Castanea, mixed with Liquidambar, Myrica, Ilex, Nyssa, Rhus, Ulmus, Juglans, Betula and Pterocary, etc. Herbaceous pollen and fern spores are common, mainly represented by Poaceae, Artemisia as well as Polypodiaceae type, respectively. Two pollen zones with an altitude boundary of 200m above sea level are recognized based on the variations of some important taxa. Our results show that the pollen flora generally reflects the main components and distribution along the Longchi hill of the current zonal evergreen broad-leaved forests, though there are some discrepancies. In addition, we integrate the pollen flora with other representative surface pollen data from the Yangtze River Delta to propose several pollen signal proxies for better identifying the subtropical evergreen forest type, the mixed deciduous-evergreen broad-leaved forest pattern and the human-disturbed deciduous broad-leaved forest type. The results will provide important and improved information for the study of Quaternary paleovegetation and paleoclimate in the Yangtze River Delta areas.