摘要
厘清喀斯特地区表土孢粉与现代植被的关系是解译地层孢粉的基础,是恢复古环境的前提。文章通过分析广西环江喀斯特观测站的24个表土和苔藓样品,探讨其表土孢粉与现代植被的对应关系。结果表明:(1)共鉴定出49科/属孢粉类型,花粉组合中针叶类占优势,含量为32.49%~78.65%,其中以松属为主;其次为草本(9.41%~53.43%),以禾本科、菊科和玉蜀黍属为主;阔叶乔灌木类最低,含量为2.94%~33.49%,以豆科、大戟科、木兰科和桑科为主。表土花粉组合基本能反映环江站周围植被的总体特征;(2)草本花粉在玉米地含量最高(53.43%),主要以玉蜀黍属为主;次生林、草地、人工恢复林及桑林的蕨类孢子含量较高,分别达53.91%、49.00%、48.88%和46.04%;(3)主成分分析可较好区分草地、人工恢复林、构树林、次生林和玉米地,但桑林并不能很好地被区分,可能与采样时间及其花粉保存条件等有关;(4)孢粉浓度大小依次为人工恢复林>桑林>玉米地>次生林>草地>构树林,这可能与植被组成、土层扰动及孢粉保存条件等有较大关系。
This study takes topsoil pollen samples from different land use methods/vegetation types at the Huanjiang Observation and Research Station for Karst Ecosystems,Chinese Academy of Sciences(hereinafter referred to as the Huanjiang Station)as its research object.The Huanjiang Station is located in the southern part of Huanjiang Maonan Autonomous county,Hechi City,Guangxi and represents typical karst peak-cluster depression ecosystem in China.It is situated in the subtropical monsoon climate zone,with a mild climate and abundant rainfall throughout the county.The forest communities are primarily composed of evergreen broadleaf forests,followed by some deciduous broadleaf and mixed evergreen coniferous and broadleaf forests.This study aims to explore the characteristics of topsoil pollen assemblages under different land use methods/vegetation types at the Huanjiang Station.It seeks to establish a correlation between topsoil pollen and modern vegetation to provide theoretical references for ecological restoration,Quaternary paleoenvironmental and paleoclimate reconstruction,and historical research on human interference activities in the study area and comparable karst regions.All 24 topsoil and moss samples were prepared at the Key Laboratory of Environment Change and Resources Use in Beibu Gulf(Nanning Normal University),Ministry of Education.Standard conventional acid-base methods were then used to extract the pollen.About 30 g of dry topsoil samples and about 3 g of dry moss samples were weighted.HCL was added to dissolve calcareous minerals,and HF was used to digest silica,followed by several rinses with distilled water.Finally,a 7-μm nylon sieve was employed to remove unwanted small particles,and the pollen was collected to a 5-ml centrifuge tube.A tablet containing Lycopodium spores(10,315 grains per tablet)was added to each sample to calculate pollen concentration.The percentage of each pollen taxon is based solely on the total terrestrial pollen sum,whereas the percentage of spores is calculated from the combined sum of both pollen and spores.Pollen and spores were identified with the use of a Leica DM4000 B microscope at 200/400x magnification.More than 300 pollen grains of per sample were counted.The program Tilia(Version 1.7.16)was used to construct the pollen diagrams.Principal Component Analysis(PCA)was applied to the data pollen percentage with the use of Canoco(Versions 5.0)software.The results show:(1)A total of 49 pollen taxa(genera or family)were identified from 24 topsoil(or moss)samples collected at Huanjiang Station.Among these,25 taxa belonged to trees and shrubs,mainly including Pinus,Cupressaceae/Taxodiaceae,Fabaceae,Euphorbiaceae,Magnoliaceae,and Moraceae.Pinus had the highest content,averaging 56.8%and reaching a maximum of 87.62%.Additionally,20 taxa were Herbaceous,mainly Poaceae,Asteraceae,and Araceae.Fern spores were mainly from Nephrolepis,Dicranopteris,and Pteris.Freshwater algae(Concentricystis)spores were also present in the samples.(2)There was a large variation in the concentration of topsoil pollen among different land use methods/vegetation types in the depression of Huanjiang Station.The lowest pollen concentration was 4,131 grains·g^(−1) in topsoil samples from secondary growth forest,while the highest was 416,781 grains·g^(−1) in planted restoration forest.The average pollen concentration was relatively low,at 54,432 grains·g^(−1).A significant difference was observed between the average concentrations of topsoil samples(27,371 grains·g^(−1))and moss samples(189,738 grains·g^(−1)).Among all samples,Pinus pollen had the highest concentration,reaching 19,232 grains·g^(−1),followed by Asteraceae(2,280 grains·g^(−1)),Poaceae(1,535 grains·g^(−1)),and Euphorbiaceae(1,461 grains·g^(−1)).In addition,fren spore concentration was relatively high,with an average of 6,353 spores·g^(−1).(3)PCA results showed that the pollen assemblage was well separated and heterogeneous,allowing for rough classification.Among different land use methods/vegetation types,corn fields corresponded clearly with Zea,and coniferous woodland corresponded clearly with Moraceae,enabling effective differentiation.Secondary growth forest and planted restoration forest were relatively well grouped.The conclusion are as follows:(1)The topsoil pollen composition corresponds well with the vegetation types of each land use method/vegetation type,and the combined topsoil pollen assemblage can basically reflect the overall characteristics of vegetation surrounding the depression.(2)PCA analysis can effectively distinguish grassland,planted restoration forest,coniferous woodland,secondary growth forest,and cornfields,indicating that topsoil pollen from different land use methods/vegetation types exhibits clear differentiation.However,mulberry forests cannot be well distinguished,which may be related to the timing of Morus sampling and pollen preservation conditions.(3)Pollen concentrations of different land use methods/vegetation types follow the order:planted restoration forest>mulberry forest>cornfield>secondary growth forest>grassland>coniferous woodland.This pattern may be closely related to vegetation composition,soil disturbance,and pollen preservation conditions.
作者
郝秀东
陆雅娴
欧阳绪红
李立学
秦琳娟
韦嘉胜
王艾岚
黄琳倩
林春雨
HAO Xiudong;LU Yaxian;OUYANG Xuhong;LI Lixue;QIN Linjuan;WEI Jiasheng;WANG Ailan;HUANG Linqian;LIN Chunyu(Key Laboratory of Beibu Gulf Environment Change and Resource Utilization,Nanning Normal University,Ministry of Education,Nanning,Guangxi 530001,China;Guangxi Key Laboratory of Earth Surface Processes and Intelligent Simulation,Nanning Normal University,Nanning,Guangxi 530001,China;Key Laboratory of Karst Dynamics,MNR&GZAR/Institute of Karst Geology,CAGS,Guilin,Guangxi 541004,China;State Key Laboratory of Modern Paleontology and Stratigraphy,Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,Nanjing,Jiangsu 210008,China;Guangxi Academy of Science,Guangxi Mangrove Research Center,Guangxi Key Laboratory of Mangrove Conservation and Utilization,Beihai,Guangxi 536000,China)
出处
《中国岩溶》
北大核心
2025年第5期1036-1048,共13页
Carsologica Sinica
基金
国家自然科学基金项目(U20A2048,42001076)
广西自然科学基金(2023GXNSFBA026263,2025GXNSFAA069308)
中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室开放基金(223109)
广西岩溶动力学重大科技创新基地开放基金项目(KDL&Guangxi202204)
广西红树林保护与利用重点实验室开放基金项目(GKLMC-201902)。
关键词
表土孢粉组合
环江站
喀斯特
土地利用方式
植被类型
topsoil pollen assemblage
Huanjiang Station
karst
land use methods
vegetation types
