# Homogeneous Selection and Dispersal Limitation Drive Phyllosphere Fungal Community Assembly in Constructed Wetland Ecosystems

## TL;DR

This study shows that plant type strongly influences leaf fungi in constructed wetlands, with both environmental factors and chance events shaping fungal communities.

## Contribution

The study integrates fungal community diversity, assembly mechanisms, and network structure in constructed wetlands.

## Key findings

- Plant type significantly influences fungal community diversity and composition.
- Fungal community assembly is jointly driven by selection, dispersal, and drift processes.
- Network analysis identified hub taxa that may be important for community stability.

## Abstract

Wetlands are important ecosystems that help clean water, store carbon, reduce flooding, and provide habitat for wildlife. Many natural wetlands have been lost due to farming and development, and one solution is to create new “constructed wetlands”. In these human-made systems, plants and the tiny organisms living on them play a major role in keeping the ecosystem healthy. Among these organisms, fungi that live on leaves are especially important because they can affect plant growth, disease resistance, and overall ecosystem stability. In this study, we looked at fungi living on the leaves of different plant species in a constructed wetland that was converted from farmland. We found that the type of plant strongly influenced the kinds of fungi present. Both environmental conditions and chance events shaped how fungal communities formed, with neither completely dominating. We also identified a few key fungal species that appear to play central roles in the community and may help maintain stability. Our findings show that choosing certain plants can influence fungal communities, and managing these relationships may help improve the design and success of constructed wetlands for environmental restoration.

Constructed wetlands (CWs) are widely used for ecological restoration, but their microbial assembly mechanisms and ecological functions remain poorly understood, limiting the optimization of restoration strategies. In this study, we investigated foliar fungal communities associated with dominant plant types in a CW converted from farmland by employing high-throughput sequencing. We analyzed community composition, diversity, assembly processes, and co-occurrence network structure to identify potential keystone taxa. Our results showed that plant type significantly influenced fungal community diversity and composition (α < 0.05). Assembly processes were jointly driven by heterogeneous selection (36.48%), dispersal-related processes (35.49%), and drift (24.70%), indicating comparable contributions of deterministic and stochastic processes. Co-occurrence network analysis revealed a modular structure and identified several hub taxa based on topological indices, suggesting their potential importance for network stability. This study provides an integrated perspective that links community diversity, assembly mechanisms, and network structure, providing insights for improving CW vegetation management and microbial regulation strategies. Future studies should explore and validate the functional roles of hub taxa and test the generalizability of these patterns across multiple regions and seasons.