生态学报2017，Vol.37Issue(24)：8254-8263,10.DOI:10.5846/stxb201701080064
氮沉降对温带森林土壤甲烷氧化菌的影响
Effects of nitrogen addition on methanotrophs in temperate forest soil
摘要
Abstract
Several studies have shown that increasing nitrogen deposition affects methane uptake in the forest ecosystems;however,the microbial mechanisms underlying this phenomenon remain unclear.In the present study,the seasonal variation in methanotroph abundance and community structure in a temperate forest receiving long-term differential nitrogenous compound addition treatments (45 kg N hm-2 a 1 using (NH4) 2SO4,NH4Cl,and KNO3) in Changbai mountains,were investigated by using real-time PCR,cloning,and sequencing.Methanotroph pmoA gene abundances were similar among all fertilized and control plots in summer (1.54× 106-3.20× 106 copies g-1 dry soil);however,in fall,it was significantly lower in the (NH4)2SO4 treatment (4.61× 105±2.61× 105copies g-1 dry soil) than that in the control plots (4.03×106±1.2× 106 copies g-1 dry soil).In both summer and fall,the methanotroph community was dominated by Type Ⅰ methanotrophs,consisting of Methylobacter-group (Type Ⅰ) and Methylococcus-group (Type Ⅰ),with the relative abundance varying from 70.6％-85.4％.The dominant clade of Type Ⅰ methanotroph,Methylobacter-group (Type Ⅰ) showed no significant variance among all treatments in summer,but were present in significantly lower proportions in the (NH4)2SO4(52.7％±6.5％) and NH4Cl (56.1％±8.9％) treatments than in the control in fall.In contrast,Methylococcus-group (Type Ⅰ) showed an increasing trend in the (NH4) 2SO4 and NH4Cl treatments compared to that in the control plots in fall.Overall,these results suggested that the addition of NH4+-N fertilizers could inhibit the growth of methane oxidizing bacteria,and change their community composition.The inhibition effect became more obvious in fall than in summer,owing to the interactive effects of soil moisture and temperature in summer,whereas NO3--N addition showed no significant effect on the abundance and community composition of methanotrophs.These results were consistent with the previous observation that ammonium-based fertilizer addition reduced methane uptake from temperate forest soil in fall rather than in summer,and provided insights into the microbial mechanisms driving methane uptake in temperate forests under long-term nitrogen addition treatments.关键词
甲烷氧化菌/pmoA基因/森林土壤/氮沉降Key words
methanotrophs/pmoA gene/forest soil/nitrogen deposition引用本文复制引用
张丹丹,莫柳莹,陈新,张丽梅,徐星凯..氮沉降对温带森林土壤甲烷氧化菌的影响[J].生态学报,2017,37(24):8254-8263,10.基金项目
国家自然科学基金项目(41203053,41275166) （41203053,41275166）
