Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou 310058, China.
Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Sci Total Environ. 2019 Mar 25;658:723-731. doi: 10.1016/j.scitotenv.2018.12.144. Epub 2018 Dec 14.
Archaea play crucial roles in geochemical cycles and influence the emission of greenhouse gases in acidic soils. However, little is known about the distribution pattern of total archaeal diversity and community composition with increasing elevation, especially in acidic agricultural ecosystems. Terraces, characterized by vertical climate changes and unique hydrological properties, are "natural experiments" to explore the spatial distribution of microorganisms along elevation in paddy soils. Here we investigated the diversity and structure of soil archaeal communities in nine increasingly elevated acidic paddy soils of the Yunhe terrace, China. Archaeal communities were dominated by Methanomicrobia of Euryarchaeota (38.5%), Group 1.1a-associated cluster (SAGSCG-1) of Thaumarchaeota (22.0%) and Subgroup-6 (previously described as crenarchaeotal group 1.3b) of Bathyarchaeota (17.8%). The archaeal phylotype richness decreased with increasing elevation. Both the species richness and phylogenetic diversity of the archaeal communities were significantly negatively correlated with soil available phosphorus (AP) content according to linear regression analyses. The archaeal communities differed greatly between soils of increasing elevation, and were roughly clustered into three groups, mostly in relation to AP contents. A variation partitioning analysis further confirmed that edaphic factors including the content of AP (17.1%), nitrate (7.83%), soil organic carbon (4.69%), dissolved organic carbon (4.22%) and soil pH (4.07%) shaped the archaeal community. The variation of soil properties were probably induced by elevation. The co-occurrence network indicated a modular structure of the archaeal community. Overall, our results emphasized that soil AP content was the best predictor of archaeal diversity and community structure, and the impacts of elevation on soil archaeal communities were not diminished by long-term rice cultivation, although minor compared with the effects of soil properties.
古菌在地球化学循环中发挥着关键作用，并影响酸性土壤中温室气体的排放。然而，人们对总古菌多样性和群落组成随海拔升高的分布模式知之甚少，特别是在酸性农业生态系统中。梯田具有垂直气候变化和独特的水文特性，是探索稻田土壤中微生物沿海拔空间分布的“自然实验”。在这里，我们研究了中国云和梯田 9 个逐渐升高的酸性稻田土壤中土壤古菌群落的多样性和结构。古菌群落主要由广古菌门的甲烷微菌（38.5%）、泉古菌门的 Group 1.1a 相关聚类（SAGSCG-1）（22.0%）和广古菌门的亚群 6（先前描述为古菌 1.3b 亚群）（17.8%）组成。古菌的种型丰富度随海拔升高而降低。线性回归分析表明，古菌群落的物种丰富度和系统发育多样性与土壤有效磷（AP）含量呈显著负相关。随着海拔的升高，土壤中的古菌群落差异很大，大致可分为 3 组，主要与 AP 含量有关。变分分配分析进一步证实，土壤特性（包括 AP 含量（17.1%）、硝酸盐（7.83%）、土壤有机碳（4.69%）、溶解有机碳（4.22%）和土壤 pH 值（4.07%）等土壤因素影响了古菌群落。土壤性质的变化可能是由海拔引起的。共生网络表明古菌群落具有模块结构。总的来说，我们的研究结果强调了土壤 AP 含量是古菌多样性和群落结构的最佳预测因子，尽管与土壤特性的影响相比，海拔对土壤古菌群落的影响较小，但长期水稻种植并没有减弱这种影响。
