# Vegetation-mediated assembly of rhizosphere fungal communities and their ecological drivers in constructed wetland systems

## TL;DR

This study explores how different plants in constructed wetlands influence the fungal communities in their roots, and how soil properties and ecological processes shape these communities.

## Contribution

The study reveals the combined effects of vegetation, soil properties, and ecological processes on rhizosphere fungal community assembly in constructed wetlands.

## Key findings

- Vegetation types significantly influence the diversity and composition of rhizosphere fungal communities.
- Soil properties like pH, salinity, and nutrient levels strongly correlate with fungal community structure.
- Stochastic processes and dispersal limitation are key drivers of fungal community assembly in constructed wetlands.

## Abstract

Constructed wetlands (CWs) are widely applied for restoring degraded wetland ecosystems and enhancing pollutant removal. Rhizosphere fungal communities play a crucial role in these ecosystems by mediating nutrient cycling and pollutant degradation.

This study examined the diversity patterns and assembly mechanisms of rhizosphere fungal communities across seven different CW types with distinct vegetation compositions within a farmland-to-wetland conversion system.

We identified 6,243 operational taxonomic units (OTUs), with sequencing coverage exceeding 98% across all vegetation types. Significant differences in phylogenetic diversity were observed between vegetation types. The dominant fungal classes were Sordariomycetes and Glomeromycetes, with ternary plot analysis indicating that different plant species selectively enriched distinct fungal lineages. Soil physicochemical properties, including pH, salinity, organic matter content, total potassium, and available phosphorus, showed significant variation across the different vegetation types. These soil factors were strongly correlated with the composition and diversity of rhizosphere fungal communities. Beta nearest taxon index (β MNTD) analysis indicated that both deterministic and stochastic processes contributed to community assembly, with stochastic processes exerting a stronger influence. The iCAMP model revealed that dispersal limitation was the primary factor influencing community assembly (57.13%), followed by homogeneous selection (20.53%) and drift processes (19.91%). Mantel tests showed that key environmental factors at key as soil nutrient levels, enzyme activities, and plant biomass was significantly associated with specific fungal lineages and community structure.

These findings provide new insights into ecological processes that govern rhizosphere fungal community assembly in CWs, thereby advancing the evaluation of wetland restoration effectiveness and informing microbial management strategies to optimize ecosystem services and pollutant removal in CW systems.