Long-term experimental warming alters nitrogen-cycling communities but site factors remain the primary drivers of community structure in high arctic tundra soils
Long-term experimental warming alters nitrogen-cycling communities but site factors remain the primary drivers of community structure in high arctic tundra soils
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DOI：
10.1038/ismej.2008.52
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
Jennifer K. M. Walker;K. Egger;G. Henry
中科院分区：
文献类型：
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作者：
Jennifer K. M. Walker;K. Egger;G. Henry
预计下世纪北极气温将大幅上升。北极苔原的实验性变暖已被证明可以提高植物生产力，引起群落变化，也可能改变微生物群落结构。因此，本研究的目的是确定是否实验变暖引起的变化，在土壤微生物群落的频率，相对丰度和/或丰富ofnosZ和nifH基因型的测量。五个地点在高北极沿海低地进行了为期13年的变暖实验，使用开顶室（OTCs）。网站不同的优势植物群落，土壤母质和/或水分制度。从每个站点的四个重复OTC和环境地块中采集六个土芯，并细分为上部和下部样品。通过双向聚类分析以图形方式评估末端限制性片段的频率和相对丰度的差异，并使用排列多变量方差分析（ANOVA）进行统计学检验。使用因子ANOVA比较基因型丰富度。基因型频率，相对丰度和基因型丰富度bothnosZ和nifH社区显着不同的网站，并通过OTC治疗和/或深度在一些网站。表现出最明显的治疗效果的网站是一个潮湿的莎草草甸，在那里的群落结构和基因型丰富度bothnosZ和nifH受到变暖的显着影响。虽然变暖是一个重要的因素，影响这些社区在一些网站在这个高北极低地，总的来说，网站因素是社区结构的主要决定因素。
Arctic air temperatures are expected to rise significantly over the next century. Experimental warming of arctic tundra has been shown to increase plant productivity and cause community shifts and may also alter microbial community structure. Hence, the objective of this study was to determine whether experimental warming caused shifts in soil microbial communities by measuring changes in the frequency, relative abundance and/or richness ofnosZ andnifH genotypes. Five sites at a high arctic coastal lowland were subjected to a 13-year warming experiment using open-top chambers (OTCs). Sites differed by dominant plant community, soil parent material and/or moisture regimen. Six soil cores were collected from each of four replicate OTC and ambient plots at each site and subdivided into upper and lower samples. Differences in frequency and relative abundance of terminal restriction fragments were assessed graphically by two-way cluster analysis and tested statistically with permutational multivariate analysis of variance (ANOVA). Genotypic richness was compared using factorial ANOVA. The genotype frequency, relative abundance and genotype richness of bothnosZ andnifH communities differed significantly by site, and by OTC treatment and/or depth at some sites. The site that showed the most pronounced treatment effect was a wet sedge meadow, where community structure and genotype richness of bothnosZ andnifH were significantly affected by warming. Although warming was an important factor affecting these communities at some sites at this high arctic lowland, overall, site factors were the main determinants of community structure.