模拟氮沉降和隔离降雨对杉木林土壤微生物功能基因丰度的影响  

Effects of simulated nitrogen deposition and precipitation exclusion on soil microbial functional gene abundance in a Chinese fir forest

作　　者：邱旖婷 宋鸽 金圣圣 李晓杰[1] 吕茂奎[1,2] 谢锦升 郑勇[1] QIU Yiting;SONG Ge;JIN Shengsheng;LI Xiaojie;LÜMaokui;XIE Jinsheng;ZHENG Yong(Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350117;Sanming Forest Ecosystem National Observation and Research Station,Fujian 365002)

机构地区：[1]福建师范大学湿润亚热带生态地理过程教育部重点实验室,福州350117 [2]福建三明森林生态系统国家野外科学观测研究站,福建365002

出　　处：《环境科学学报》2024年第6期375-383,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.31971447,32001169)。

摘　　要：全球环境变化因子氮沉降、干旱深刻影响森林生态系统生物多样性和生态功能,但两者交互作用如何影响森林土壤微生物的功能基因丰度鲜有报道.本研究聚焦亚热带杉木人工林,通过设置对照、氮添加处理(40 kg·hm^(-2)·a^(-1))、隔离降雨处理(隔离50%穿透雨)、氮添加与隔离降雨处理等实验处理,利用高通量定量PCR技术,研究了土壤中碳、氮和磷循环微生物相关功能基因丰度的季节变化及其影响因子.研究发现,氮添加和隔离降雨对碳、氮、磷循环相关功能基因丰度无显著影响,而季节变化显著影响这些功能基因的丰度.除硝化功能基因丰度外,其余碳、氮、磷循环功能基因丰度均在冬季高于夏季.相关性分析表明,土壤总磷含量与反硝化基因丰度呈显著正相关,与其他功能基因丰度之间呈显著负相关,表明土壤总磷可能是影响杉木林土壤微生物潜在功能的关键因子.本研究综合分析了模拟氮沉降和隔离降雨交互作用下,杉木林土壤碳氮磷元素转化相关微生物功能基因变化,为全球变化下亚热带人工林的可持续经营提供理论指导.Global environmental change,such as nitrogen(N)deposition and drought,profoundly affect biodiversity and ecological functionality in forest ecosystems,however,the combined effects of N addition and drought on the abundance of microbial functional genes in forest soils remain largely unclear.The current study was conducted in a Chinese fir plantation in subtropical regions,utilizing Soil samples collected from an experiment with four treatments:control,nitrogen addition(N,40 kg·hm^(-2)·a^(-1)),precipitation exclusion(PE,50%precipitation was excluded),and combined N and PE(PEN).The abundances of microbial functional genes involving in carbon,nitrogen and phosphorus cycling in forest soils were examined using quantitative PCR.We found that although both N addition and PE had no significant effect on the abundance of microbial functional genes,seasonal change had significant effects on the abundance of these genes,with generally higher abundance detecting in winter than in summer,except for nitrification functional genes.Moreover,correlation analysis showed that the abundance of denitrification genes was significantly and positively correlated with soil total phosphorus(TP).In contrast,the abundances of most other C,N and P cycling functional genes were negatively correlated to soil TP,underscring the vital role of soil TP in influencing potential microbial functionality in subtropical forest soils.This study provide a comprehensive evaluation of the interactive effects of N addition and precipitation exclusion on the abundance of soil C,N,P cycling associated microbial functional genes,which would have critical implications for the sustainable management of Chinese fir plantations in subtropical regions under future global change scenarios.

关 键 词：氮添加 隔离降雨 碳循环 氮循环 磷循环 功能基因 

分 类 号：X53[环境科学与工程—环境工程]