应用PLFA法分析氮沉降对缙云山马尾松林土壤微生物群落结构的影响

发布时间：2018-04-23 01:36

本文选题：氮沉降 + 土壤微生物　；参考：《环境科学》2016年09期

【摘要】：氮沉降虽可提升林地生产力却会给环境造成压力,而土壤微生物对环境变化敏感.通过野外模拟试验,探讨不同氮沉降量对马尾松土壤微生物群落的影响,探索该区域马尾松土壤微生物群落与土壤温湿度、氮沉降浓度的关系,为深入研究氮沉降对马尾松林土壤生态系统的影响提供参考.2014年5月~2015年6月在缙云山马尾松林设置3个氮添加水平和一个无氮添加的对照处理:低氮[N20,20 g·(m~2·a)~(-1)]、中氮[N40,40 g·(m~2·a)~(-1)]、高氮[N60,60 g·(m~2·a)~(-1)]和对照[N0,0g·(m~2·a)~(-1)],采用磷脂脂肪酸(PLFA)标记法和ACE(automated soil CO_2 exchange station,UK)自动土壤呼吸监测系统分别对土壤微生物群落结构、土壤温度和土壤湿度进行分析测定.结果表明:1季节变化对土壤细菌、真菌、放线菌及总PLFA量有显著影响(P0.05),各类型均在春季最高,冬季最低.在不同季节,土壤微生物量对氮沉降的响应趋势不同,总体而言,春季和秋季氮沉降抑制了土壤微生物量,夏季和冬季氮沉降促进了土壤微生物量.2氮沉降对土壤微生物群落结构有显著影响(P0.05),在春季和夏季,低、中氮沉降使土壤微生物丰富度指数和多样性降低,使均匀度指数升高;在秋季和冬季,低氮和中氮则使丰富度指数、多样性指数及均匀度指数升高.高氮沉降使4个季节土壤微生物丰富度指数、多样性指数和均匀度指数降低.3相关性分析表明,氮沉降浓度与细菌呈极显著负相关(P0.01),与总PLFA呈显著负相关(P0.05);土壤温度与放线菌呈极显著负相关;土壤湿度与细菌和总PLFA呈极显著正相关.综上所述,缙云山马尾松林土壤微生物群落结构主要受土壤湿度和氮沉降的影响,受土壤温度影响较小.
[Abstract]:Although nitrogen deposition can increase the productivity of forest land, it will put pressure on the environment, and soil microorganism is sensitive to environmental change. The effects of different nitrogen deposition on soil microbial communities of Pinus massoniana were studied through field simulation experiments, and the relationship between soil microbial communities and soil temperature, humidity and concentration of nitrogen deposition in this area was explored. In order to study the effect of nitrogen deposition on soil ecosystem of Pinus massoniana forest, from May 2014 to June 2015, three levels of nitrogen addition and one control treatment without nitrogen addition were set up in Pinus massoniana forest from May 2014 to June 2015: low nitrogen [N2020 g / m ~ (2 a) ~ (-1)], medium nitrogen The microbial community structure of soil was studied by ACE(automated soil CO_2 exchange (ACE(automated soil exchange station UKK) automatic soil respiration monitoring system (ACE(automated soil CO_2 exchange station UKK), [N40C 40 g / m ~ (2 a) ~ (-1)], N ~ (60 ~ (60) g / m ~ (-1)) and control [N _ 0 ~ (0 g) ~ (2) A ~ (1) ~ (-1))], and the results were as follows: (1) the soil microbial community structure was determined by ACE(automated soil CO_2 exchange station (UKK) automatic soil respiration monitoring system, and the results were compared with those of the control. Soil temperature and soil moisture were analyzed and measured. The results showed that the seasonal variation of 1 / 1 had a significant effect on soil bacteria, fungi, actinomycetes and total PLFA contents, and all types were highest in spring and lowest in winter. In different seasons, the response of soil microbial biomass to nitrogen deposition was different. In general, nitrogen deposition inhibited soil microbial biomass in spring and autumn. Nitrogen deposition in summer and winter promoted soil microbial biomass .2 nitrogen deposition significantly affected soil microbial community structure. In spring and summer, low nitrogen deposition reduced soil microbial richness index and diversity, and increased evenness index. In autumn and winter, low and medium nitrogen increased the richness index, diversity index and evenness index. Soil microbial richness index, diversity index and evenness index decreased by 3. 3 correlation analysis with high nitrogen deposition. There was a very significant negative correlation between soil temperature and actinomycetes, and a very significant positive correlation between soil moisture and bacteria and total PLFA. To sum up, the soil microbial community structure of Pinus massoniana forest in Jinyun Mountain was mainly affected by soil moisture and nitrogen deposition, but not by soil temperature.
【作者单位】：西南大学资源环境学院三峡库区生态环境教育部重点实验室;四川沃尔宜环保科技有限公司;
【分类号】：X172

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