模拟氮沉降对杨树人工林土壤微生物群落结构的影响  

Effects of elevated nitrogen deposition on microbial community structure in poplar plantation

作　　者：赵超[1] 张文文[1] 阮宏华[1] 徐长柏 曹国华 

机构地区：[1]南京林业大学生物与环境学院,南京210037 [2]江苏省东台市国营林场,江苏东台224200

出　　处：《生态学杂志》2015年第2期360-366,共7页Chinese Journal of Ecology

基　　金：国家重点基础研究发展计划项目(2012CB416904);江苏高校优势学科建设工程项目(PAPD);江苏高校协同创新计划项目资助

摘　　要：在杨树人工林中,采用随机区组设计、野外定位模拟氮沉降试验,研究氮沉降对土壤微生物群落结构的影响。设计5个氮沉降水平,分别为：空白对照N0（0 kg·hm-2·a-1）、低氮N1（50 kg·hm-2·a-1）、中氮N2（100 kg·hm-2·a-1）、高氮N3（150 kg·hm-2·a-1）、超高氮N4（300 kg·hm-2·a-1）。从2012年5月开始在生长季（5-10月）每月进行施氮处理。施氮2年后,运用磷脂脂肪酸（PLFA）方法对0-10 cm土层中的微生物群落结构进行了测定。结果表明,施氮处理未改变微生物PLFAs总量水平,但使细菌和革兰氏阳性细菌PLFAs含量上升;中氮处理使真菌PLFAs含量显著下降,其他水平的氮处理对其影响则不显著;中氮、高氮和超高氮处理使丛枝菌根真菌和原生动物的PLFAs含量减少。除低氮处理外,其他施氮处理样地中的土壤微生物结构都发生了改变。这些结果表明,短期氮沉降会影响杨树人工林土壤微生物群落结构,并最终可能对生态系统功能产生影响。Soil microbial communities may respond to anthropogenic increases in ecosystem nitro-gen （N） availability, and the microbial response may ultimately feed back on ecosystem carbonand N dynamics. We examined the effects of nitrogen deposition on soil microbial communitystructure composition in a Chinese poplar plantation subject to simulated nitrogen deposition fortwo years at Dongtai Forest Farm of Jiangsu Province, China. Nitrogen loadings were designed at5 levels as NO （control）, low-N （50 kg · hm-2 · a-l）, mdeium-N （100 kg ·hm-2 · a-1）,high-N （ 150 kg · hm-2·a -1 ）, ultra high-N （300 kg · hm-2 · a-2 ）, respectively. Nitrogen addi-tion was carried out within the forest monthly during May and August in 2012-2013. Soil sampleswere collected at 0-10 cm depths in October 2013. Soil microbial community structm＇e composi-tion was measured using phospholipid fatty acid （PLFA） analysis. Nitrogen additions did notchange the total content of PLFAs but increased the amount of bacterial and gram-positive bacte-rial PLFAs. The content of fungal PLFAs did not change significantly, except under the mediumlevel N addition. Nitrogen additions of medium, high, ultrahigh levels decreased the amount ofarbuscular mycorrhizal fungal and protistic PLFAs. Principal component analysis （PCA） ofmicrobial PLFA data showed that microbial community structure were changed in all N-addedplots except the low-N trreatment. Our findings indicated that soil community structure can beinfluenced by short-term N additions in the poplar plantation.

关 键 词：氮沉降 土壤微生物群落 磷脂脂肪酸 杨树人工林 

分 类 号：S714.3[农业科学—林学]