Land-use types shape soil microbial compositions under rapid urbanization in the Xiong'an New Area, China

Abstract For urban planning and infrastructural projects, considerable attention has been paid to the relationship between soil biota, especially protists, and edaphic conditions in various land-use types having different plant species in the Xiong'an New Area of China. To elucidate this relationship, we assessed edaphic variables and soil biota compositions and compared them among 5 habitat types: human-made forests, crop cultivations, arid rivers, Baiyangdian (BYD) Lake, and around oil wells. In all, 12 experimental plots from terrestrial and aquatic ecosystems were assessed using high-throughput sequencing of environmental DNA, targeting the V3–V4 region of the 16S rRNA gene, internal transcribed spacer 1, and V4 region of the 18S rRNA gene for bacteria, fungi, and protists, respectively. The abundance of bacterial and protist communities was higher than fungi, possibly because fungi prefer acidic soil conditions and likely have greater susceptibility to anthropogenic activities. Across all experimental plots, land-use types contributed the most to the β-diversity of soil biota, followed by soil moisture. Diversity and richness were significantly higher at aquatic habitats than at terrestrial habitats. Predictive metagenomic analysis of trophic groups predicted relatively high frequency of functional genes from bacterial metabolism pathways (carbohydrate and amino acid); contrary to expectation, phototrophic protists, but not fungal symbionts and protistan consumers, were the dominant group at the BYD Lake. Geographical coordinates showed significant (P