Bacteria and archaea play important roles in soil biogeochemical cycles and the health of terrestrial organisms. They usually coexist in various soil habitats; however, the ecological patterns of bacteria and archaea in the same soil habitats still remain unclear. Here, we compared the community features of the two domains in bulk soils under different vegetation covers. Generally, both bacterial abundance and α-diversity were higher than those of archaea, and the differences were more noticeable in agricultural soils than in non-agricultural saline soils. Compared with bacteria, the archaeal community showed more niche limitation with less widely distributed taxa. Interestingly, similar edaphic factors were correlated with both bacteria and archaea but with opposite effects, of which salinity was the most important driving factor. With the rise of salinity, bacterial α-diversity and abundance decreased, but archaeal diversity increased. Majority of the dominant bacterial taxa showed significantly negative correlation with salinity, such as Alphaproteobacteria, Betaproteobacteria, Acidobacteria and Nitrospirae. In contrast, except Thaumarchaeota, most archaeal predominant taxa from Euryarchaeota, Woesearchaeota and Nanohaloarchaeota were positively related to salinity. Furthermore, network analyses showed that not only bacteria but also considerable archaea-related nodes, edges and potential keystone taxa existed in the networks, especially in saline soils, indicating that archaea also had important positions in microbial co-occurrence networks. These results extended our understanding on the ecological patterns of prokaryotes in terrestrial ecosystems.

细菌和古细菌在土壤生物地球化学循环和陆地生物的健康中起着重要作用。它们通常共存于各种土壤生境中。然而，在同一土壤生境中细菌和古细菌的生态模式仍然不清楚。在这里，我们比较了不同植被覆盖下散装土壤中两个域的群落特征。通常，细菌丰度和α多样性高于古细菌，并且在农业土壤中的差异比在非农业盐渍土中更明显。与细菌相比，古细菌群落显示出更多的生态位限制，分布较不广泛的分类单元。有趣的是，类似的细菌因子与细菌和古细菌都相关，但作用相反，其中盐度是最重要的驱动因子。随着盐度的升高，细菌的α多样性和丰度降低，但古细菌多样性增加。多数优势细菌类群与盐度呈显着负相关，如α变形蛋白细菌，β变形蛋白细菌，酸性细菌和硝化螺旋藻。相比之下，除了Thaumarchaeota以外，大多数来自Euryarchaeota的古细菌占主导地位的类群，Woesearchaeota和Nanohaloarchaeota与盐度呈正相关。此外，网络分析表明，不仅细菌，而且网络中还存在大量古细菌相关的节，边缘和潜在的梯形分类群，特别是在盐渍土中，这表明古细菌在微生物共生网络中也具有重要地位。这些结果扩展了我们对陆地生态系统中原核生物生态模式的理解。