Moisture, salinity and pH co-driving spatial heterogeneity of Verrucomicrobial populations in Xilin River landscape

Abstract:

[Objective] In this paper, our main goal was to clarify the spatial heterogeneity and environmental driver of Verrucomicrobial populations from different landscape components in Xilin River basin. [Methods] Based on the difference of habitat and microtopography, we selected the landscape components of aquatic riverbed center, riverbed edge and oxbow lakebed, hygric low floodplain and high floodplain, xeric low terrace and high terrace. Then we employed 16S rRNA gene high-throughput sequencing to study the landscape heterogeneity of soil Verrucomicrobial populations from different landscape components. We also explored environmental variables driving landscape heterogeneity of soil Verrucomicrobial populations combining with environmental variables (e.g. soil moisture). [Results] Spatial distribution of Verrucomicrobial populations showed convergent characteristics within landscape components and divergent characteristics between landscape components. The members of Chthoniobacter from Spartobacteria class and Prosthecobacter from Verrucomicrobiae class were mainly distributed in the aquatic riverbed center (RC), showing significant positive correlation with sand particle (P<0.05). Those of Opitutae class were mainly distributed in hygric floodplain, showing positive correlation with pH (P<0.05 or P>0.05). DA101_soil_group members of Spartobacteria class were mainly distributed in the xeric terrace, showing significant positive correlation with salinity and nutrients (P<0.01). Variation partitioning analyses of single, two groups and three groups of environmental variables showed that moisture, salinity and pH explained 24.7% & 21.4%, 24.3% & 22.7% and 23.1% & 20.8% of landscape heterogeneity of Verrucomicrobial populations, respectively. [Conclusion] Verrucomicrobial populations demonstrated landscape heterogeneity in Xilin River basin. Members of Chthoniobacter and Prosthecobacter were indicators of the riverbed center landscape component, DA101_soil_group was the indicator of the terrace landscape components. The combination of moisture, salinity with pH co-drove the landscape heterogeneity of Verrucomicrobial populations.