模拟氮沉降对杨树人工林土壤微生物群落碳源利用类型的影响

发布时间：2018-05-05 19:25

本文选题：氮沉降 + 土壤微生物　；参考：《南京林业大学学报(自然科学版)》2017年05期

【摘要】：【目的】探究氮沉降对杨树人工林土壤微生物群落特征的影响。【方法】以江苏省东台地区沿海杨树人工林为对象,采用Biolog ECO微平板技术,设置4种氮添加水平:N0(0 kg/(hm~2·a))、N1(50 kg/(hm~2·a))、N2(100 kg/(hm~2·a))、N3(150 kg/(hm~2·a))模拟不同浓度氮沉降,经过2 a生长季(5—10月)处理,测定杨树林土壤微生物群落碳源利用变化情况。【结果】N2处理可以增强杨树人工林土壤微生物对碳源的代谢能力,氮添加浓度过高则会产生抑制作用;土壤中微生物对胺类和酚类利用程度表现出较大差异,其中,酚类在高浓度氮处理(N3)时利用程度最高,胺类在低浓度氮(N1)条件下利用程度最高;硝态氮和平均颜色变化率(AWCD)、Shannon多样性均具有显著正相关性(P0.05),微生物代谢水平及其结构变化受到硝态氮影响较大。主成分分析表明,PC1和PC2可以表示施氮对微生物群落代谢多样性产生的差异,其中,PC1的方差贡献率最大,碳水化合物、酚类呈负相关(碳源相关系数分别为-0.869、-0.780),氨基酸、羧酸呈正相关(碳源相关系数分别为0.702、0.821),是起主要分异作用的碳源;PC2涵盖了聚合物和胺类两种碳源大类,其中聚合物呈负相关(相关系数为-0.688),胺类呈正相关(相关系数为0.802)。【结论】氮添加会导致杨树人工林土壤微生物群落对碳源利用类型改变,土壤中硝态氮含量与微生物生长代谢及功能多样性呈显著正相关;六大类碳源中碳水化合物、羧酸是影响土壤微生物群落功能多样性的主要碳源。
[Abstract]:[objective] to investigate the effect of nitrogen deposition on soil microbial community characteristics of poplar plantation. [methods] A Biolog ECO microplate technique was used to study poplar plantation in Dongtai area, Jiangsu Province. Four kinds of nitrogen addition levels N _ 0 ~ 0 kg/(hm~2 a ~ (1) ~ (1) ~ (50 kg/(hm~2 / a) N _ 2 ~ (2 +) ~ (100) kg/(hm~2 ~ (150) kg/(hm~2 a ~ (1) were set up to simulate nitrogen deposition at different concentrations, and were treated during the 2-year growth season (~ (5 ~ 10) months). [results] nitrogen treatment could enhance the metabolic ability of soil microorganisms to carbon source in poplar plantation. The degree of utilization of amines and phenols in soil showed great difference, among which, the utilization degree of phenols was the highest in the treatment of high concentration nitrogen (N _ 3), and the highest in the condition of low concentration N _ (1). There was a significant positive correlation between the diversity of NO3-N and the average color change rate and Shannon diversity. The microbial metabolic level and its structural changes were greatly affected by NO3-N. Principal component analysis (PCA) showed that the difference of nitrogen application on the metabolic diversity of microbial communities could be indicated by PC1 and PC2. The variance contribution rate of PC1 was the largest, the carbohydrates and phenols were negatively correlated (the correlation coefficient of carbon source was -0.869- 0.780), amino acid, amino acid and carbohydrate, respectively. Carboxylic acid has a positive correlation (the correlation coefficient of carbon source is 0.702 / 0.821, respectively). PC2, a major carbon source, covers two kinds of carbon sources, polymer and amine. Among them, there was a negative correlation between polymer and amine (the correlation coefficient was -0.688, and the correlation coefficient was 0.802). [conclusion] nitrogen addition could result in the change of soil microbial community of poplar plantation. The content of nitrate in soil was positively correlated with microbial growth metabolism and functional diversity and carboxylic acid was the main carbon source affecting the functional diversity of soil microbial community.
【作者单位】：南方现代林业协同创新中心南京林业大学生物与环境学院;
【基金】：国家重点基础研究发展计划(2012CB416904) 江苏省基础研究计划(自然科学基金)青年基金项目(BK20130973) 江苏高校优势学科建设工程资助项目(PAPD)
【分类号】：S714.3

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