Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
School of Ecology and Environmental Sciences & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming, 650091, China.
Environ Sci Pollut Res Int. 2019 Oct;26(28):29127-29137. doi: 10.1007/s11356-019-06109-7. Epub 2019 Aug 7.
Archaea play a vital role in Earth's geochemical cycles, but the factors that drive their distribution between sediments and water-level-fluctuating zones in the East Dongting Lake (EDL) wetland are poorly understood. Here, we used Illumina MiSeq to investigate the variation in the soil archaeal community structure and diversity among sediments and four water-level-fluctuating zones (mudflat, sedge, sedge-Phragmites, and Phragmites) in the EDL wetland. Diverse archaeal assemblages were found in our study, Crenarchaeota, Euryarchaeota, and ammonia-oxidizing and methanogenic subset were the dominant groups, and all their abundances shifted from sediment to water-level-fluctuating zones. The principal coordinates analysis and cluster analysis showed that the overall archaeal community structure was separated into two clusters: cluster I contained nine samples from sediment, mudflat, and sedge zones, whereas cluster II contained six samples from sedge-Phragmites and Phragmites zones. Archaeal diversity was significantly highest in sediment and lowest in Phragmites zone soils. The Mantel test showed that the variation in archaeal community structure was significantly positively correlated with soil water content and pH. The relative abundances of Crenarchaeota and Nitrososphaerales decreased with soil water content, while Euryarchaeota and Methanomicrobiales increased with soil water content. The relative abundance of Methanomicrobiales significantly decreased with pH (R = 0.34-0.48). Chao 1, observed operational taxonomic units, Shannon index, and Simpson index all correlated significantly positively with water content (R = 0.40-0.60), while Shannon and Simpson indexes both correlated significantly negatively with pH (R = 0.20-0.37). Our results demonstrated that the variations in the archaeal community structure were markedly driven by soil water content and pH in the EDL wetland. Our findings suggested that archaeal communities shifted among sediment and four water-level-fluctuating zones, highlighting that the spatiotemporal heterogeneity of greenhouse gas flux in small scale should be taken into account for accurate prediction of greenhouse gas emissions in the Dongting Lake area, especially on the background of climate change and human activities.
古菌在地球的地球化学循环中起着至关重要的作用，但在东洞庭湖（EDL）湿地中，驱动它们在沉积物和水位波动区之间分布的因素还了解甚少。在这里，我们使用 Illumina MiSeq 来研究 EDL 湿地沉积物和四个水位波动区（泥滩、莎草、莎草-芦苇和芦苇）之间土壤古菌群落结构和多样性的变化。我们的研究发现了多样的古菌组合，广古菌门、泉古菌门和氨氧化菌和产甲烷菌亚群是主要群体，它们的丰度都从沉积物转移到了水位波动区。主坐标分析和聚类分析表明，整个古菌群落结构分为两个群集：群集 I 包含来自沉积物、泥滩和莎草区的 9 个样本，而群集 II 包含来自莎草-芦苇和芦苇区的 6 个样本。古菌多样性在沉积物中最高，在芦苇区土壤中最低。Mantel 检验表明，古菌群落结构的变化与土壤含水量和 pH 值呈显著正相关。广古菌门和硝化螺旋菌的相对丰度随着土壤含水量的增加而降低，而泉古菌门和甲烷微菌门的相对丰度随着土壤含水量的增加而增加。甲烷微菌门的相对丰度与 pH 值呈显著负相关（R = 0.34-0.48）。Chao1、观察到的操作分类单元、香农指数和辛普森指数均与含水量呈显著正相关（R = 0.40-0.60），而香农指数和辛普森指数均与 pH 值呈显著负相关（R = 0.20-0.37）。我们的结果表明，古菌群落结构的变化主要受到 EDL 湿地土壤含水量和 pH 值的驱动。我们的研究结果表明，古菌群落在沉积物和四个水位波动区之间发生了转移，这突出表明，在小规模下，温室气体通量的时空异质性应该被考虑在内，以便更准确地预测洞庭湖地区的温室气体排放，尤其是在气候变化和人类活动的背景下。
