Microbial community structure and function: The effect of silvicultural burning and topographic variability in northern Alberta
Microbial community structure and function: The effect of silvicultural burning and topographic variability in northern Alberta
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DOI：
10.1016/j.soilbio.2009.01.014
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发表时间：
2009-04
影响因子：
9.7
通讯作者：
M. Swallow;S. Quideau;M. D. MacKenzie;B. Kishchuk
中科院分区：
文献类型：
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作者：
M. Swallow;S. Quideau;M. D. MacKenzie;B. Kishchuk
森林地面化学和微生物群落可受到森林土地管理的影响，例如采伐和规定焚烧。在这里，我们使用磷脂脂肪酸（PLFA）和多碳源底物诱导呼吸（MSIR）分析来表征不同造林处理的落叶、混交木和针叶林地面的微生物群落。这些地点只收获茎，保留10%，造林处理包括在场地上均匀分布刀削林，然后燃烧或不燃烧。与未燃烧区相比，燃烧区微生物生物量较低，NO3−浓度较高。然而，燃烧似乎对森林地面微生物群落的结构和功能没有影响。另一方面，在干旱月份（8月采样），森林地面微生物群落的组成似乎受到地形位置的强烈影响，而不是与林分相关的差异。位于高海拔采伐点的微生物群落结构相似，而位于低海拔的针叶林和混交林采伐点的微生物群落结构相似，与落叶林不同。在高海拔地点和低海拔地点之间，森林地面的小气候条件的差异可能会选择一些微生物群而不是其他微生物群。指标分析发现，真菌PLFA生物标志物（20:1ω9c）与海拔较高的地点有很强的相关性，而放线菌生物标志物（10Me19:0）与海拔较低的落叶地点有很强的相关性。在高海拔和低海拔地区观察到的微生物群落结构差异似乎与湿度的季节性模式有关，因为先前在该地区的研究发现，在月降水量较高的时期，海拔没有明显的影响。
Forest floor chemistry and microbial communities can be influenced by forest land management, such as harvesting and prescribed burning. Here, we used phospholipid fatty acid (PLFA) and multiple carbon-source substrate-induced respiration (MSIR) analyses to characterize microbial communities of deciduous, mixedwood and coniferous boreal forest floors with different silvicultural treatments. The sites were stem-only harvested with 10% retention, and silvicultural treatments consisting of slash being evenly distributed on the site and then burned, or not burned. The burned sites exhibited lower microbial biomass and greater NO3−concentrations than the unburned sites. However, burning appeared to have no effect on forest floor microbial community structure or function. On the other hand, during drier months (August sampling), the composition of forest floor microbial communities appeared to be strongly influenced by topographic position rather than stand related differences. Harvested sites located at higher elevations had similar microbial communities, regardless of the overstory composition, while coniferous and mixedwood sites located at lower elevations had similarly structured microbial communities that were distinct from deciduous sites. Differences in microclimatic conditions of the forest floor between higher elevation sites and lower elevations sites may select for some microbial groups over others. Indicator analysis found a strong association of a fungal PLFA biomarker (20:1ω9c), with sites at higher elevation, while a biomarker for actinomycetes (10Me19:0) was strongly associated with deciduous sites at lower elevation. Structural differences in microbial communities observed between sites at higher and lower elevations appear to be linked to seasonal patterns in moisture, as previous studies in this region found no apparent effect of elevation during times of higher monthly precipitation.