Comparative Analysis of Microbial Functional Diversity Between Rhizosphere and Bulk Soil Across Three Ecological Zones: Lowland, Riparian, and Sedge Habitats

Abstract

The functional diversity of microbial communities plays a crucial role in nutrient cycling and ecosystem dynamics in wetlands. In this study, we investigated the microbial communities in the rhizosphere (soil zone adjacent to plant roots) and bulk soil of three wetland vegetation types: sedge (J. acutus), riparian, and lowland (Typha-dominated). Random samples were collected from eight bulk soil and five rhizosphere sites per vegetation type. DNA extraction, shotgun library preparation, next-generation sequencing, functional profiling using funprofiler, canonical correspondence analysis (CCA), beta diversity analysis, and chemical/physical analysis were conducted. Our results revealed significant differences in functional diversity between bulk soil and rhizosphere (P-value = 0.01 vs. 0.32), suggesting distinct microbial communities associated with root systems, possibly influenced by vegetation type. The riparian vegetation exhibited the most dispersed functional diversity, likely attributed to its diverse plant species. Interestingly, the lowland bulk soil displayed greater functional diversity compared to its rhizosphere, while the rhizosphere showed less dispersed functional diversity, possibly due to the uniformity of vegetation in this area. These findings enhance our understanding of wetland microbial ecosystems, highlighting the influence of vegetation type and soil properties on microbial functional diversity.