甘南亚高寒草甸不同坡向土壤微生物群落分布特征

发布时间：2018-03-28 11:20

  本文选题：亚高寒草甸　切入点：坡向　出处：《生态环境学报》2017年11期

【摘要】：为了探究坡向变化对土壤微生物群落分布的影响,采用稀释涂布平板法和最大可能数(MPN)法测定了亚高寒草甸3年间(2014年、2015年和2016年)不同坡向土壤微生物类群及2016年微生物功能群的分布特征,并分析了微生物类群及功能群分布与植物生物量、土壤理化性质等环境因子的关系。结果表明,不同坡向土壤微生物群落分布差异显著(P0.05),由阳坡向阴坡变化时,土壤微生物类群总数整体呈上升趋势。同一坡向土壤细菌数量所占比例最大,放线菌次之,真菌最小;2016年微生物总数较2014年与2015年分别下降了61.75%和68.23%。土壤微生物功能群总数随阳坡向阴坡变化呈现先增加后减少的趋势,氨化细菌数量显著高于固氮菌与硝化细菌数量(P0.05)。相关分析表明,亚高寒草甸坡向梯度上土壤微生物群落分布是多种环境因子共同作用的结果,其中,土壤含水量、全磷和土壤p H值是影响土壤微生物类群分布的主导因子,固氮菌、硝化细菌数量与有机碳含量相关性达到显著水平。综合分析表明,阴坡土壤环境明显优于阳坡,更适宜土壤微生物进行生命活动。
[Abstract]:To explore the effects of slope changes on the distribution of soil microbial communities, The distribution characteristics of soil microbial groups and microbial functional groups in subalpine meadow for three years (2014, 2015 and 2016) were determined by dilution coating plate method and maximum maximum number of MPN method. The relationship between the distribution of microbial groups and functional groups and environmental factors, such as plant biomass, soil physical and chemical properties, was also analyzed. The results showed that the distribution of soil microbial communities in different slope directions was significantly different (P0.05), and the variation from the positive slope to the shady slope was significant. The total number of soil microbes was on the rise. The proportion of bacteria in the same slope was the largest, followed by actinomycetes. The total number of microorganisms in 2016 was 61.75% and 68.23% lower than that in 2014 and 2015, respectively. The total number of soil microbial functional groups increased first and then decreased with the change of the positive slope to the negative slope. The number of ammoniated bacteria was significantly higher than that of nitrogen-fixing bacteria and nitrifying bacteria (P0.050.The correlation analysis showed that the distribution of soil microbial community on the gradient of subalpine meadow slope was the result of various environmental factors, among which, soil water content. Total phosphorus and soil pH were the main factors affecting the distribution of soil microbial groups. The correlation between the amount of nitrogen-fixing bacteria, nitrifying bacteria and the content of organic carbon reached a significant level. The comprehensive analysis showed that the soil environment of shady slope was obviously superior to that of sunny slope. It is more suitable for life activities of soil microbes.
【作者单位】： 西北师范大学地理与环境科学学院;
【基金】：国家自然科学基金项目(31360114;31760135)
【分类号】：S812.2
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本文编号：1676109