抗生素添加对不同演替阶段岩溶生态系统土壤有机质激发效应的影响  

Influence of Antibiotic Addition on Priming Effect of Soil Organic Matter from Different Successional Stages in Karst Ecosystems

作　　者：李强[1,2,3] 汤秦 吴锐[1,2,3] LI Qiang;TANG Qing;WU Rui(Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,P.R.China;Pingguo Guangxi,Karst Ecosystem,National Observation and Research Station/Pingguo Baise,Karst Ecosystem,Guangxi Observation and Research Station,Pingguo 531406 P.R.China;Key Laboratory of Karst Dynamics Ministry of Natural Resources,Guangxi/International Research Center on Karst under the Auspices of United Nations Educational,Scientific and Cultural Organization,Guilin 541004,P.R.China)

机构地区：[1]中国地质科学院岩溶地质研究所,广西桂林541004 [2]广西平果喀斯特生态系统国家野外科学观测研究站/百色平果喀斯特生态系统广西野外科学观测研究站,广西平果531406 [3]自然资源部、广西岩溶动力学重点实验室/联合国教科文组织国际岩溶研究中心,广西桂林541004

出　　处：《生态环境学报》2024年第11期1717-1726,共10页Ecology and Environmental Sciences

基　　金：广西壮族自治区科技重大专项(桂科AA24206020);广西重点研发计划(桂科AB21196065)。

摘　　要：外源有机物添加会改变土壤有机质周转并产生激发效应,而添加抗生素后微生物的基质诱导呼吸则会受到选择性抑制,进而影响土壤有机质矿化过程。利用“空间代替时间”法结合选择性抑制诱导呼吸技术,通过室内实验研究环己酰亚胺和链霉素添加对中国西南岩溶区不同演替阶段生态系统土壤有机质的影响。结果表明:向土壤加入单一或者联合抑制细菌或真菌的抗生素时呈现诱导呼吸量增加的变化规律。尽管链霉素对诱导呼吸抑制作用不显著,但环己酰亚胺能够对以r-策略菌或k-策略菌为主导的土壤产生显著抑制作用。由于不同演替阶段生态系统下的土壤激发效应指数均小于1,表明产生负激发效应,并以表观激发和真实激发的形式显示,进而涉及活性基质的利用以及土壤固有有机质的分解。虽然链霉素和环己酰亚胺对细菌和真菌产生抑制作用,但不能对古菌、病毒和胞外酶产生抑制作用。因此,单独使用链霉素、环己酰亚胺或者同时使用二者时,土壤有机质仍能被微生物利用进而造成官能团相对比例发生变化。该研究结果为揭示土壤有机质负激发效应产生的原因以及明晰土壤有机质化学组分的相对稳定性提供了理论依据。Soil organic matter(SOM),the largest organic carbon reservoir in terrestrial ecosystems,plays an important role in global carbon cycles.The addition of exogenous substances alters the turnover of soil organic matter,and thus produces priming effects.If antibiotics that can inhibit bacteria or fungi are added to the soil as exogenous substances,substrate-induced respiration is selectively inhibited.Although extensive research has been conducted on the factors and mechanisms of the priming effect of soil organic matter,there has been no research on the priming effect on the selective induction of respiration inhibition technology for soil organic matter utilization in karst ecosystems at different successional stages.Therefore,this study used the“space instead of time”method to investigate the influence of cycloheximide and streptomycin on soil organic matter in different successional stages of karst ecosystems in southwestern China.In September 2021,soil samples from primary forests,secondary forests,shrubland,grasslands,and cornfields were collected from Gongcheng Yao Autonomous County in the Guangxi Zhuang Autonomous Region,which has a subtropical monsoon climate.The soil was brown and calcareous.The results showed that the addition of single or combined antibiotics that inhibit bacteria or fungi to the soil induced an increase in respiration rate.Owing to the strong adsorption ability of alkaline streptomycin on the soil particles,its inhibitory effect on induced respiration was not significant.The addition of cycloheximide significantly inhibited soil respiration,which was dominated by r-strategy or k-strategy microorganisms.The soil organic matter priming effect index under different successional stages was less than 1,indicating the occurrence of negative priming effects,which are displayed in the form of apparent priming effects and real priming effects.Although streptomycin and cycloheximide can inhibit bacteria and fungi,they cannot inhibit archaeal,viral,or extracellular enzymes.Therefore,when strept

关 键 词：岩溶 土壤有机质矿化 环己酰亚胺 链霉素 13C核磁共振 

分 类 号：P593[天文地球—地球化学] P599[天文地球—地质学] X142[环境科学与工程—环境科学] X144