两种母岩发育森林土壤微生物生物量碳代谢的差异性  

Analysis of the Differences and Causes in Microbial Biomass Carbon Metabolism Characteristics of Forest Soils Developed from Two Types of Rocks

作　　者：付瑞桐 万翔宇 杨馨逸 李德军[2,3] 胡培雷[2,3] 段鹏鹏 张玉玲 FU Ruitong;WAN Xiangyu;YANG Xinyi;LI Dejun;HU Peilei;DUAN Pengpeng;ZHANG Yuling(College of Land and Environment,Shenyang Agricultural University,Shenyang 110866,China;Key Laboratory of Agro-Ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China;Guangxi Key Laboratory of Karst Ecological Processes and Services,Huanjiang Observation and Research Station for Karst Ecosystems,Chinese Academy of Science,Huanjiang 547100,Guangxi,China)

机构地区：[1]沈阳农业大学土地与环境学院,沈阳110866 [2]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125 [3]广西自治区重点实验室,中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《土壤学报》2024年第5期1432-1443,共12页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(U21A2007,U22A20560,42107381);广西优良用材林资源培育重点实验室课题项目(22-B-01-04)资助。

摘　　要：针对不同母岩发育土壤的微生物生物量碳代谢特征及驱动因子不明确的科学问题,以石灰岩和碎屑岩两种母岩发育的森林土壤为研究对象,利用18O-H2O标记测定微生物生长速率、微生物呼吸速率、微生物生物量碳利用效率(CUE)以及微生物周转时间,并结合土壤理化性质、土壤有机质矿物保护特性和土壤酶活性以及微生物生物量和群落组成,明确岩性对森林土壤微生物生物量碳代谢的影响机制。结果表明:石灰岩发育土壤的pH和0.05mm~0.002 mm粒径含量高于碎屑岩发育土壤,而有机碳(SOC)、全氮(TN)、可溶性碳(DOC)、C︰P和N︰P却低于碎屑岩发育土壤(P<0.05);石灰岩发育土壤交换性钙镁(Ca+Mg)和游离态铁铝((Fe+Al)d)含量高于碎屑岩发育土壤,但非晶态铁铝((Fe+Al)o)含量则低于碎屑岩发育土壤;石灰岩发育土壤碳氮磷循环、相关酶活性均显著低于碎屑岩发育土壤(P<0.05);石灰岩发育土壤微生物生物量磷(MBP)高于碎屑岩发育土壤,但微生物生物量碳(MBC)、真菌细菌比(F︰B)和革兰氏阳性菌阴性菌比(G+︰G-)则显著低于碎屑岩发育土壤(P<0.05);石灰岩发育土壤微生物生长速率和周转速率显著高于碎屑岩发育土壤(P<0.05),但微生物呼吸速率和CUE在两种土壤之间差异并不显著。土壤微生物生长速率和微生物周转速率均与土壤pH、(Ca+Mg)︰(Fe+Al)o、(Ca+Mg)︰SOC、(Fe+Al)d︰SOC和革兰氏阴性细菌呈显著正相关(P<0.05),而与DOC、铁铝结合态有机碳、酶活性、MBC︰MBN、F︰B和G+︰G-比呈显著负相关(P<0.05)。此外,土壤CUE与MBC和MBC︰MBN呈显著负相关(P<0.05);微生物呼吸速率仅与酚氧化酶活性呈显著负相关(P<0.05)。两种岩石发育的森林土壤微生物生物量碳代谢受生物和非生物因素的控制,这一研究结果为解释不同母岩发育森林土壤有机碳库的差异提供参考。【Objective】Microbial biomass carbon(C)metabolism is vital in the formation and stabilization of organic C in soil,constituting a critical parameter in the models of terrestrial ecosystems.Yet,the variances in the microbial C metabolism indices in soils developed from different lithological origins remain undefined.【Method】To address the scientific gap in the characteristics and driving factors of microbial biomass C metabolism in soils developed from different rocks,we sampled forest soils developed from limestone and clastic rocks as research objects.Using 18O-H2O labeling,we measured the microbial growth rate,respiration rate,carbon use efficiency(CUE),and turnover time.Combined with soil physicochemical properties,soil organic matter mineral protection characteristics,soil enzyme activity,and microbial biomass and community composition,we clarified the influencing mechanism of lithology on forest soil microbial biomass C metabolism.【Result】The findings indicate that the pH and the 0.002~0.05 mm particle content in limestone-derived soils surpass those in clastic rock-derived soils,whereas soil organic carbon(SOC),total nitrogen(TN),dissolved organic carbon(DOC),C:P and N:P ratios were lower in limestone-derived soils(P<0.05).The limestone-developed soils had a higher content of exchangeable calcium and magnesium(Ca/Mg)and free iron and aluminum((Fe+Al)d)than the clastic rock-developed soils,but the content of amorphous iron and aluminum((Fe+Al)o)was lower than that in the clastic rock-developed soils.Furthermore,the enzyme activity related to C,N,and P cycling in limestone-developed soils was significantly lower than that in clastic rock-developed soils(P<0.05).In addition,the microbial biomass phosphorus(MBP)in limestone-developed soils was higher than that in clastic rock-developed soils,but microbial biomass carbon(MBC),fungi:bacteria ratio(F:B),and Gram-positive to Gram-negative bacteria ratio(G+:G-)were significantly lower than those in clastic rock-developed soils(P<0.05).The microbial growth

关 键 词：石灰岩 碎屑岩 森林土壤 微生物生物量碳代谢 磷脂脂肪酸 酶 有机质 

分 类 号：S154.1[农业科学—土壤学]