模拟氮沉降对轿子雪山急尖长苞冷杉林土壤微生物碳源代谢多样性的影响  

Effects of simulated nitrogen deposition on soil microbial carbon source metabolic diversity of Abies georgei Orr var.smithii forest in Jiaozi Snow Mountain

作　　者：彭湖淞 袁吉有 PENG Hu-song;YUAN Ji-you(Institute of International Rivers and Ecological Security,Yunnan University,Kunming 650000,China;School of Ecology and Environment,Yunnan University,Kunming 650000,China)

机构地区：[1]云南大学国际河流与生态安全研究院,云南昆明650000 [2]云南大学生态与环境学院,云南昆明650000

出　　处：《环境生态学》2025年第1期89-100,共12页Environmental Ecology

基　　金：国家自然科学基金项目(41867009)资助。

摘　　要：土壤微生物碳源代谢对自然界物质循环和能量流动有着至关重要的作用,而人类活动导致大气中含氮化合物越来越多,可能导致土壤微生物底物利用能力有一定的变化。本研究在轿子雪山急尖长苞冷杉林(Abies georgei Orr var.smithii)开展3年的模拟氮沉降实验,采用(NH_(4))_(2)SO_(4)、NaNO_(3)、NH_(4)NO_(3)3种N添加源,每种N源分4种处理,从低至高记为CK[control 0 kg/(hm^(2)·a)]、低N[Low-N 5 kg/(hm^(2)·a)]、中N[Medium-N 15 kg/(hm^(2)·a)]、高N[High-N 30 kg/(hm^(2)·a)],借助Biolog-Eco微平板技术,探究氮沉降下土壤微生物的代谢活性变化以及对不同碳源的利用程度大小。结果表明:与对照相比,1)氮添加降低了土壤pH、全磷、速效磷含量,增加了土壤全氮、有机碳含量,对土壤温度及含水量基本无影响,且土壤理化性质的改变与土壤微生物碳源代谢有一定的相关关系。2)氮添加均显著降低了土壤微生物碳源代谢活性。3)不同氮添加显著降低了微生物对糖类、羧酸、氨基酸、胺类碳源代谢利用率。4)不同氮处理均显著降低了土壤微生物碳源利用的丰富度指数,对土壤微生物碳源利用的均匀度指数影响不显著,对土壤微生物碳源利用的Shannon多样性指数影响不一。综上所述,3年的氮添加降低了轿子雪山急尖长苞冷杉林土壤微生物对碳源的代谢多样性,且土壤微生物碳源代谢与氮沉降下土壤理化性质的改变有着密切关系。研究结果可为进一步研究高海拔寒温性针叶林生态系统土壤有机质分解及转化提供参考。Soil microbial carbon source metabolism plays a crucial role in the natural material cycle and energy flow,and the increasing nitrogen compounds caused by human activities in the atmosphere may lead to certain changes in the utilization capacity of soil microbial substrates.In this study,a three-year simulated nitrogen deposition experiment was carried out in Abies georgei Orr var.smithii forest in Jiaozi Snow Mountain.Three N addition sources,(NH_(4))_(2)SO_(4),NaNO_(3),and NH_(4)NO_(3),were used.Each N source was divided into four treatments,from low to high,marked as CK[control 0 kg/(hm^(2)·a)],low N[Low-N 5 kg/(hm^(2)·a)],medium N[Medium-N 15 kg/(hm^(2)·a)],and high N[High-N 30 kg/(hm^(2)·a)].With the help of Biolog-Eco microplate technology,the changes of metabolic activity and the utilization of different carbon sources of soil microorganisms under nitrogen deposition were explored.The results showed that:Compared with the control,1)nitrogen addition decreased soil pH,total phosphorus and available phosphorus content,increased soil total nitrogen and organic carbon content,had no effect on soil temperature and water content,and the change of soil physical and chemical properties was related to soil microbial carbon source metabolism.2)Nitrogen addition reduced the metabolic activity of soil microbial carbon source significantly.3)Different nitrogen additions significantly reduced the metabolic utilization of carbohydrates,carboxylic acids,amino acids,and amines by microorganisms.4)Different nitrogen treatments significantly reduced the richness index of soil microbial carbon source utilization,had no significant effect on the evenness index of soil microbial carbon source utilization,and had different effects on the Shannon diversity index of soil microbial carbon source utilization.In summary,three years of nitrogen addition reduced the metabolic diversity of soil microorganisms on carbon sources in Abies georgei Orr var.smithii forest in Jiaozi Snow Mountain,and the metabolism of soil microbial carbon

关 键 词：氮沉降 碳源利用多样性 土壤理化性质 轿子雪山 急尖长苞冷杉林 

分 类 号：S714.3[农业科学—林学]