华北平原冬小麦田土壤胞外/内酶活性对长期CO_(2)浓度升高的响应  

Response of soil extracellular/intracellular enzyme activity to long⁃term elevated CO_(2)in a winter wheat field of North China Plain

作　　者：张馨月 白家韶 韩雪[1] 许吟隆[1] ZHANG Xinyue;BAI Jiashao;HAN Xue;XU Yinlong(Institute of Environment and Sustainable Development in Agriculture,Chinese Academy of Agricultural Sciences,Beijing 100081,China)

机构地区：[1]中国农业科学院农业环境与可持续发展研究所,北京100081

出　　处：《生态学报》2023年第20期8504-8505,8506-8515,共12页Acta Ecologica Sinica

基　　金：国家重点研发计划课题项目(2019YFA0607403);国家自然基金青年基金项目(31901174)。

摘　　要：针对农田胞外和胞内酶活性响应CO_(2)浓度升高认识不足的现状,依托华北平原冬小麦种植区北京昌平试验站长期开放式CO_(2)富集平台,设置常规和升高两组CO_(2)浓度处理,研究冬小麦田土壤胞外和胞内酶活性的变化及影响因素。结果表明:CO_(2)浓度升高促进胞外碳获取酶活性,不影响胞外氮获取酶活性以及全部胞内酶活性。通过量化碳、氮获取酶的胞外胞内比发现,CO_(2)浓度升高在冬小麦成熟期增强了碳获取酶胞外胞内比,但降低了氮获取酶胞外胞内比。胞外碳、氮获取酶活性都与土壤pH值呈负相关;而胞内碳获取酶活性与土壤含水量正相关,胞内氮获取酶活性与微生物生物量负相关。CO_(2)浓度升高导致上述大部分酶活性变化驱动因素的作用消失,仅存在土壤全氮与胞内碳获取酶活性负相关。研究结果强调了对胞内酶开展研究的重要性,为理解土壤过程对全球变化因素的响应提供了新见解。Currently,there is still a lack of sufficient studies on the responses of soil enzymes to climate change in the agroecosystem.In an attempt to address this research gap,we investigated the variation of soil extracellular and intracellular enzyme activities and its driving factors under long⁃term elevated CO_(2)treatment in a winter wheat farmland from North China Plain.Our study was conducted at the free air CO_(2)enrichment experiment of Changping,Beijing.The planted winter wheat was exposed to ambient and elevated levels of CO_(2)(400μmol/mol vs 550μmol/mol),respectively.We collected the surface soil samples from four different growth stages during the winter wheat growing season.Our results showed that the elevated CO_(2)treatment significantly improved activities of extracellular carbon acquiring enzyme.However,activities of extracellular nitrogen acquiring enzyme and both intracellular carbon and nitrogen acquiring enzyme were not affected by the elevated CO_(2)treatment.In addition,we also quantified the ratio of extracellular to intracellular enzyme activity which previous studies did not pay enough attention to this before.Based on the statistical results,the elevated CO_(2)treatment increased the ratio of extracellular to intracellular carbon acquiring enzyme activity but decreased the ratio of extracellular to intracellular nitrogen acquiring enzyme activity at the maturity stage of winter wheat.According to Pearson correlation analysis,both extracellular carbon and nitrogen acquiring enzyme activities negatively correlated with soil pH value.The influencing factors of intracellular enzyme activity were different from that of extracellular enzyme activity.To be specific,the intracellular carbon acquiring enzyme activity positively correlated with soil water content while intracellular nitrogen acquiring enzyme activity negatively correlated with microbial biomass carbon.Nevertheless,the effect of above influencing factors was unable to be detected under the elevated CO_(2)treatment.Only intracellula

关 键 词：CO_(2)浓度上升 华北平原 冬小麦田 胞外酶 胞内酶 

分 类 号：S512.11[农业科学—作物学]