CO_(2)浓度升高对土壤碳降解酶活性和有机碳的影响  

Effects of elevated CO_(2) concentration on soil carbon degrading enzyme activity and soil organic carbon

作　　者：樊陈启 陈骥[2] 张怡晅 项兴佳 张锋 FAN Chenqi;CHEN Ji;ZHANG Yixuan;XIANG Xinjia;ZHANG Feng(School of Resource and Environmental Engineering,Anhui University,Hefei 230601,China;State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi′an 710075,China;Xi Shuang Ban Na Tropical Botanical Garden,Chinese Academy of Sciences,Mengla 666303,China)

机构地区：[1]安徽大学资源与环境工程学院,合肥230601 [2]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710075 [3]中国科学院西双版纳热带植物园,勐腊666303

出　　处：《生态学报》2025年第7期3192-3203,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(U2102221)。

摘　　要：二氧化碳(CO_(2))浓度的升高影响了土壤微生物过程,微生物分泌的胞外酶又会介导土壤生物化学反应,从而影响土壤碳循环。然而,当前尚不清楚当CO_(2)浓度升高时,土壤胞外酶中的碳降解酶活性和土壤碳含量将如何变化。基于2002—2021年全球野外实验数据,通过整合分析法探讨了CO_(2)浓度升高对酶活性和土壤有机碳的影响,并进一步分析了酶活性变化与土壤有机碳之间的关系。结果表明:(1)CO_(2)浓度升高使纤维素酶和木质素酶的活性分别提高了12.51%和9.88%,有机碳含量增加了8.04%。(2)有机碳含量变化与木质素酶活性变化呈现正相关(P<0.01),但与纤维素酶活性变化无显著相关。(3)模型选择分析表明,实验方法显著影响两种酶的活性,特别是FACE实验。此外,土壤有机氮含量和年均降雨量对木质素酶活性的提高也具有显著影响。由此得出结论:CO_(2)浓度升高使碳降解酶活性增强;外界环境因素以及实验因素对酶活性的增强也有一定的刺激作用,而有机碳含量的增加可能与木质素酶的“酶锁”作用有关。总之,CO_(2)浓度升高增加了土壤有机碳量,促进土壤碳循环;此外,土壤氮含量、实验方法、年平均降雨量以及CO_(2)浓度增量的影响也不能忽视。Elevated atmospheric carbon dioxide(eCO_(2))concentrations are affecting soil microbial processes.Extracellular enzymes secreted by microorganisms will mediate soil biochemical reactions,thus affecting soil carbon cycling.However,it is not clear how the soil carbon degrading enzyme activity included in soil extracellular enzymes and soil carbon content change when CO_(2) concentration increases.In this paper,global field experimental data(2002—2021)were collected,and the effects of elevating CO_(2) concentration on enzyme activity and soil organic carbon were investigated by meta-analysis,and the relationship between enzyme activity and soil organic carbon was further studied.The results showed that:(1)the activity of cellulase and ligninase under eCO_(2) treatment was increased by 12.51%and 9.88%,respectively.The organic carbon content was increased by 8.04%.(2)The change of organic carbon content was significantly positively correlated with the change of ligninase activity(P<0.01),but not significantly correlated with the change of cellulase activity.(3)Model selection analysis showed that the experimental method had a significant impact in activity of the two enzymes,in particular the FACE experiment;Soil organic nitrogen content and mean annual precipitation had significant effects on ligninase activity enhancement.It is concluded that the activity of carbon degrading enzyme is enhanced with eCO_(2).External environmental factors and experimental factors also stimulated the enhancement of enzyme activity,and the increase of organic carbon content may be related to the“enzyme locking”effect of ligninase.In conclusion,eCO_(2) increased soil organic carbon content and promoted soil carbon cycle.In addition,the effects of soil nitrogen content,experimental methods,mean annual precipitation and the elevation of atmospheric carbon dioxide concentration can not be ignored.

关 键 词：CO_(2)浓度升高 纤维素酶 木质素酶 土壤有机碳 碳-气候反馈 

分 类 号：S154.2[农业科学—土壤学]