广西西北喀斯特不同植被不同土层的土壤颗粒有机质  

Soil particulate organic matter of different soil horizons with different vegetation in karst areas of northwestern Guangxi

作　　者：江周 何寻阳[2,3] 韦映雪 胡乐宁[1,4] 冯书珍 JIANG Zhou;HE Xunyang;WEI Yingxue;HU Lening;FENG Shuzhen(School of Environment and Resource,Guangxi Normal University,Guilin,Guangxi 541000,China;Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha,Hunan 410125,China;Huanjiang Observation and Research Station for Karst Ecosystems,Chinese Academy of Sciences,Huanjiang,Guangxi 547100,China;Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection,Guilin,Guangxi 541000,China;Medical College of Guangxi University of Science and Technology,Liuzhou,Guangxi 545006,China)

机构地区：[1]广西师范大学环境与资源学院,广西桂林541000 [2]中国科学院亚热带农业生态研究所,湖南长沙410125 [3]中国科学院环江喀斯特生态系统观测研究站,广西环江547100 [4]珍稀濒危动植物生态与环境保护教育部重点实验室,广西桂林514000 [5]广西科技大学医学院,广西柳州545006

出　　处：《湖南农业大学学报（自然科学版）》2020年第2期198-205,252,共9页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：国家重点研发计划项目(2016YFC0502404);国家自然科学基金项目(31870503、41671298)。

摘　　要：以广西西北喀斯特地区不同植被(草丛、灌丛、原生林)生态系统表层(0~10 cm)及深层(70~100 cm)土壤为研究对象,采用热裂解–气相–质谱(Pyr–TMAH–GC/MS)技术,研究不同植被表层与深层土壤颗粒有机质(POM)的变化特征。结果表明:表层土壤的pH值、有机碳、总氮、总磷、碱解氮、速效磷和速效钾含量均随植被的正向演替呈上升趋势;草丛表层土壤的有机碳、总磷和碱解氮含量均显著高于深层土壤的(P<0.05);灌丛表层土壤的有机碳、总氮、总磷、碱解氮、速效磷和速效钾含量均显著高于深层土壤的(P<0.05),灌丛表层土壤的pH值和总钾含量显著低于深层土壤的(P<0.05);原生林表层土壤的总磷、速效磷和速效钾含量显著高于深层土壤的(P<0.05);随着植被的正向演替,土壤POM总量呈增加趋势,表层土壤POM总量显著高于深层土壤的;土壤POM热裂解产物类型主要有木质素类、酚类、芳烃、多环芳烃及脂类化合物,木质素类化合物仅存在于表层土壤,稠环芳烃(此处指除萘和茚外的多环芳烃)占比则随植被的正向演替呈下降趋势;植被显著影响POM总量和POM热裂解产物中对羟基苯基、稠环芳烃、脂肪酸、正构烯烃、萘、氰的占比,土层深度显著影响POM总量和POM热裂解产物中对羟基苯基、愈创木基、丁香酚基、茚、脂肪酸、酮、苯、烷基苯、酚类和氰的占比,植被与土层的交互作用显著影响POM热裂解产物中对羟基苯基、萜烯和脂肪酸的占比;POM总量与有机碳、总氮、总磷、碱解氮、速效钾和速效磷含量呈显著正相关,与容重和总钾含量呈显著负相关,稠环芳烃与有机碳、总氮、总磷、碱解氮、速效磷和速效钾含量呈显著负相关,且碱解氮和pH值显著影响POM化合物组成。可见,在喀斯特地区,土壤POM含量能反映土壤中潜在活性养分含量,可作为喀斯特地区评价不同植被恢复对土壤有机质库及土Taking the surface(0-10 cm) and deep(70-100 cm) soils from different vegetation ecosystem, i.e. tussock, shrub and primary forest as the research object in the karst area of northwestern Guangxi, China. Using pyrolysis gas chromatography-mass spectrometry(Py-GC-MS/MS) technique, we investigated the changing characteristics of soil particulate organic matter(POM) with different vegetation. The results showed that the p H value and the contents of organic carbon, total nitrogen, total phosphorus, alkali-decomposed nitrogen, available phosphorus and available potassium of surface soil all increased with the positive succession of vegetation;the contents of organic carbon, total phosphorus and alkali-hydrolyzed nitrogen of surface soil in the tussock were significantly higher than those of deep soil(P<0.05);the contents of organic carbon, total nitrogen, total phosphorus, alkali-decomposed nitrogen, available phosphorus and available potassium of surface soil in the shrub were significantly higher than those of deep soil(P<0.05), and the pH value and content of total potassium of surface soil in the shrub were significantly lower than those of deep soil(P<0.05);the contents of total phosphorus, available phosphorus and available potassium of surface soil in the primary forest were significantly higher than those of deep soil(P<0.05);along with the positive succession of vegetation, the total soil POM content increased, and the total POM content of surface soil was significantly higher than that of deep soil;the types of soil POM thermal cracking compounds mainly included lignin compounds, phenols, aromatics, polyaromatics and soil lipids, lignin compounds only existed in surface soil, and the proportion of polyaromatics(except naphthalene and indene) was a downward trend along with the positive succession of vegetation;vegetation significantly affected the total POM content and the proportions of p-hydroxyphenyl, polyaromatics, fatty acids, n-alkenes, naphthalene and cyanogens in POM thermal cracking components, soil

关 键 词：土壤颗粒有机质 植被 土层深度 土壤理化性质 热裂解气相质谱 喀斯特 广西西北 

分 类 号：S158.3[农业科学—土壤学]