森林次生演替过程中有机质层和矿质层土壤微生物残体的变化  

Variation of Microbial Residues during Forest Secondary Succession in Topsoil and Subsoil

作　　者：邵鹏帅 解宏图[2] 鲍雪莲[2] 梁超[2] SHAO Pengshuai;XIE Hongtu;BAO Xuelian;LIANG Chao(Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta,Binzhou University,Binzhou,Shandong 256603,China;Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]滨州学院山东省黄河三角洲生态环境重点实验室,山东滨州256603 [2]中国科学院沈阳应用生态研究所,沈阳110016

出　　处：《土壤学报》2021年第4期1050-1059,共10页Acta Pedologica Sinica

基　　金：中国地质调查局地质调查项目(DD20190305);国家自然科学基金重点项目(31930070)资助。

摘　　要：微生物对土壤有机质(SOM)转化和形成具有重要作用,然而微生物残体对SOM贡献的评估仍是目前的热点。以长白山5个森林次生演替序列(20 a、80 a、120 a、200 a和≥300 a)和2个土壤深度(0~5 cm有机质层和5~15 cm矿质层)为对象,利用氨基糖和中红外光谱技术,探究森林次生演替过程中微生物残体变化及其对土壤有机碳(SOC)的贡献。森林次生演替序列80~200 a显著增加了有机质层和矿质层微生物残体含量及其对SOC的贡献,而在演替300 a均显著降低。森林演替80~200 a有机质层和矿质层土壤芳香族碳组分/多糖较低,有利于微生物生物量碳(MBC)产生和微生物碳利用(高的MBC/SOC),促进微生物残体积累及其对SOC的贡献;而演替300 a芳香族碳组分/多糖较高,抑制MBC产生和微生物碳利用,导致微生物残体及其对SOC贡献的下降。SOC含量差异导致不同土壤深度微生物残体含量的变化,有机质层高的SOC产生高的MBC,进而刺激微生物残体积累;此外,有机质层难利用SOM组分高于矿质层,导致真菌残体对SOC的贡献比例下降,而细菌残体的贡献增加。【Objective】Soil microbes are an important factor driving turnover of soil organic matter(SOM),through participating in SOM formation,linking aboveground and underground ecosystems in evolution process,and influencing the structure and function of ecosystems.However,it is still a hard nut to evaluate the contribution of soil microbes(especially microbial residues)to SOM,and a hotspot of research in this aspect,due to limitation in technology.In this study,efforts were dedicated to examining(1)how forest secondary succession influences the content of microbial residues and its contribution to soil organic carbon(SOC);(2)how soil depth affects content of microbial residues and its contribution to SOC;and(3)how fungal and bacterial residues regulate the contribution of microbial residues to SOC.【Method】To explore changes in the content of microbial residues and contribution of microbial residues to SOC,soil samples were collected from the topsoil(0-5 cm)and subsoil(5-15 cm)in five plots of secondary forests with different age or succession(i.e.20 years,80 years,120 years,200 years and≥300 years)in the Changbai Mountain National Nature Reserve,Jilin,Northeast China for analysis of amino sugars,including glucosamine,galactoamine,and muramic acid,as biomarkers for microbial residues.Based on the analysis,contents of fungal and bacterial residues were worked out.Besides,soil organic matter in the sample was analyzed for composition(i.e.aromatic C,aliphatic C and polysaccharides)with fourier transform mid-IR spectroscopy.【Result】Our study showed significant increases in content of microbial residues and contribution of the residues to SOC in both topsoil and subsoil during the period of 80-200 years of the succession,whereas a reverse trend was found after 300 years.Path analysis showed that content of microbial residues was positively related to microbial biomass carbon(MBC)in the two soil layers during the succession,indicating that changes in MBC influence the accumulation of microbial residues.In the soi

关 键 词：森林次生演替 土壤深度 微生物残体 土壤有机碳 微生物生物量碳 

分 类 号：Q938.1[生物学—微生物学]