南京低山丘陵区表土及捕捉器花粉谱的差异探究

选取南京丘陵地区29处样点,分别搜集表土及捕捉器样品,开展两种采样方式下孢粉组合与植被关系研究。结果表明,南京低山丘陵地区花粉类型以松属、栎属、枫杨属、榆属、蔷薇科、菊科、禾本科为主,表土花粉组合较好地反映了现代植被特征。主成分分析可以大致区分人工草坪区、农田区以及森林区的样品。农田区表土花粉浓度最低,每克仅为4 964粒,农田的翻耕以及微生物环境是造成其花粉浓度低的重要原因;森林区花粉浓度(每克29 176粒)及花粉通量(49 358粒/平方厘米/年)均很高。人类活动的增强可能会造成孢粉浓度的下降。在探究本地区历史时期人类活动时,可运用孢粉浓度以及与农作物相关的孢粉类型的变化来分析。所有捕捉器样品的乔木花粉百分比均低于其对应的表土样品,其中以松属尤为明显。

DIFFERENCES OF MODERN POLLEN SPECTRA BETWEEN THE SURFACE SOILS AND THE POLLEN TRAPS IN THE HILLY AREAS OF NANJING,JIANGSU PROVINCE

Here we present results of 29 surface soil samples and 8 trap samples in the hilly areas of Nanjing to compare their possible difference in representation of the surrounding vegetation.The results indicates that main pollen components are Pinus,Quercus,Pterocarya,Ulmus,Rosaceae,Compositae,Gramineae,and the pollen assemblages generally reflect the whole features of modern vegetation.Principal component analysis(PCA)produced a good distribution of samples from different sampling zones,i.e.lawns,farmlands and forested areas.Farmland has the lowest average pollen concentration(4 964.28 grains/g),which may caused by ploughing and the microbial environment.Average pollen concentration and pollen influx are high in the forest(29 176.4 grains/g and 49 358.4 grains/cm2/a respectively).The decrease of pollen concentration may caused by an increase in human activities.When investigating the human activities in this area during historical times,we can perform a comprehensive analysis of pollen concentration and pollen taxa related to agriculture.Proportions of arboreal pollen types in each trap samples are lower than their corresponding surface soil samples,particularly for Pinus.