Korea Polar Research Institute, Incheon, 21990, Republic of Korea.
International Arctic Research Center, University of Alaska, Fairbanks, Alaska, USA.
Sci Rep. 2018 Jan 11;8(1):504. doi: 10.1038/s41598-017-18777-x.
Understating the microbial communities and ecological processes that influence their structure in permafrost soils is crucial for predicting the consequences of climate change. In this study we investigated the bacterial and archaeal communities along depth profiles of four soil cores collected across Alaska. The bacterial and archaeal diversity (amplicon sequencing) overall decreased along the soil depth but the depth-wise pattern of their abundances (qPCR) varied by sites. The community structure of bacteria and archaea displayed site-specific pattern, with a greater role of soil geochemical characteristics rather than soil depth. In particular, we found significant positive correlations between methane trapped in cores and relative abundance of methanogenic archaeal genera, indicating a strong association between microbial activity and methane production in subsurface soils. We observed that bacterial phylogenetic community assembly tended to be more clustered in surface soils than in deeper soils. Analyses of phylogenetic community turnover among depth profiles across cores indicated that the relative influence of deterministic and stochastic processes was mainly determined by soil properties rather than depth. Overall, our findings emphasize that the vertical distributions of bacterial and archaeal communities in permafrost soils are to a large extent determined by the variation in site-specific soil properties.
了解影响永久冻土土壤中微生物群落结构的生态过程对于预测气候变化的后果至关重要。在这项研究中，我们调查了沿阿拉斯加四个土壤芯深度剖面采集的细菌和古菌群落。细菌和古菌的多样性（扩增子测序）总体上随土壤深度的增加而降低，但它们丰度的深度模式（qPCR）因地点而异。细菌和古菌群落结构表现出特定地点的模式，土壤地球化学特征的作用大于土壤深度。特别是，我们发现核心中捕获的甲烷与产甲烷古菌属的相对丰度之间存在显著正相关，表明微生物活动与地下土壤中甲烷的产生之间存在强烈关联。我们观察到，细菌系统发育群落组装在表层土壤中比在深层土壤中更趋于聚类。对核心之间深度剖面的系统发育群落周转率的分析表明，确定性和随机性过程的相对影响主要由土壤性质决定，而不是深度。总的来说，我们的研究结果强调了永久冻土土壤中细菌和古菌群落的垂直分布在很大程度上取决于特定地点土壤性质的变化。
