云南亚热带常绿阔叶林土壤微生物量对大气氮沉降的响应  

Responses of Soil Microbial Biomass to Atmospheric Nitrogen Deposition in a Subtropical Evergreen Broad-leaved Forest of Yunnan Province

作　　者：李茂楠 刘宪斌 杨亚丽 张宝 段恩省 杨应忠 LI Mao-nan;LIU Xian-bin;YANG Ya-li(School of Chemistry,Biology and Environment,Yuxi Normal University,Yuxi,Yunnan 653100;Institute of Biology and Environmental Engineering,Yuxi Normal University,Yuxi,Yunnan 653100)

机构地区：[1]玉溪师范学院化学生物与环境学院,云南玉溪653100 [2]玉溪师范学院生物与环境工程研究院,云南玉溪653100

出　　处：《安徽农业科学》2024年第1期39-44,50,共7页Journal of Anhui Agricultural Sciences

基　　金：云南省教育厅大学生创新创业训练计划项目(2021A024);云南省教育厅大学生创新创业训练计划项目(202111390011)。

摘　　要：以玉溪市城区生态植物园中结构和功能保护较好的次生常绿阔叶林为研究地点,分别设置0、1、5、10、15和30 g/(m^(2)·a)共6个氮浓度试验处理,采用林冠下喷雾的方式处理2年,采集0~10 cm表层土壤测定土壤全碳和全氮含量、活性有机碳含量及其转化率、微生物量碳和氮含量。研究结果表明:中高浓度大气氮沉降明显增加了土壤全碳和全氮含量,降低了活性有机碳含量及其转化率,减少了微生物量碳和氮含量,说明中高浓度大气氮沉降能够影响亚热带常绿阔叶林土壤碳循环和氮循环进程,增加土壤碳库和氮库,改变土壤碳组分,延缓土壤碳转化过程,减少土壤微生物总量。数据相关分析结果表明:土壤全碳含量与大气氮沉降浓度呈多项式关系,即土壤全碳含量随大气氮沉降浓度升高而增加,在10 g/(m^(2)·a)N水平达到最大值[(31.05±1.94)g/kg],之后随着大气氮沉降浓度的继续升高而降低;土壤全氮含量与大气氮沉降浓度呈线性正相关关系,即土壤全氮含量随着大气氮沉降浓度持续升高而不断增加;土壤活性有机碳含量及其转化率、微生物量碳和氮含量与大气氮沉降浓度呈线性负相关关系,即随着大气氮沉降浓度持续升高而不断降低。In this study,the secondary evergreen broad-leaved forest with structure and function protected well in the Ecological Botanical Garden of Yuxi City Center was taken as the study site;six nitrogen concentrations of 0,1,5,10,15 and 30 g/(m^(2)·a)N were employed as the experimental treatments,respectively;spray under the forest canopy was adopted for two years,and the 0-10 cm topsoil was collected to determine the soil total organic carbon,total nitrogen,labile organic carbon and its turnover rate,microbial biomass carbon and nitrogen.The study results showed that atmospheric nitrogen deposition with the medium and high concentrations apparently increased the content of soil total carbon and nitrogen,decreased the content and turnover rate of labile organic carbon,and reduced the content of microbial biomass carbon and nitrogen,indicating that atmospheric nitrogen deposition with the medium and high concentrations could affect the process of soil carbon cycle and nitrogen cycle,expand the carrying capacity of soil carbon and nitrogen,change soil carbon components,delay the conversion process of soil carbon,and reduce the amount of soil microbial biomass of subtropical evergreen broad-leaved forests.The correlation results of data analyses showed that a polynomial relationship between soil total carbon and atmospheric nitrogen deposition concentrations occurred,i.e.,soil total carbon increased with the rise of atmospheric nitrogen deposition concentration,reached the maximum value at the 10 g/(m^(2)·a)N level[i.e.,(31.05±1.94)g/kg],and then decreased with the continuing rise of atmospheric nitrogen deposition concentration;a positive linear correlation between soil total nitrogen and atmospheric nitrogen deposition concentration occurred,i.e.,soil total nitrogen increased with the rise of atmospheric nitrogen deposition concentration;and soil labile organic carbon and its turnover rate,the content of microbial biomass carbon and nitrogen,respectively,showed a negative linear correlation with atmospheric nitrogen

关 键 词：大气氮沉降 土壤微生物量碳 土壤微生物量氮 土壤全碳 云南亚热带常绿阔叶林 

分 类 号：X172[环境科学与工程—环境科学]