Urban soil health improves with green infrastructure and reduced pathogen risks

Area of Science:

• Environmental Science
• Soil Science
• Microbiology

Background:

• Urban land-use change impacts soil microbial communities, affecting ecosystem function and public health.
• The consequences of converting cropland to urban green infrastructure on soil ecology and health are not well understood.

Purpose of the Study:

• To investigate the effects of afforestation, constructed wetlands, and urban infrastructure on soil bacterial diversity, community assembly, and pathogen risk.
• To compare these effects over a three-year period (2019-2023) against initial cropland conditions.

Main Methods:

• Utilized full-length 16S rRNA sequencing to analyze bacterial diversity and community structure.
• Employed enzyme activity assays and network analysis to assess microbial community assembly and interactions.
• Calculated a composite pathogen risk index to quantify health-related risks.

Main Results:

• Green infrastructure (constructed wetlands, afforestation) significantly enhanced bacterial diversity and community stability compared to cropland.
• Constructed wetlands showed increased bacterial richness and phylogenetic diversity, with the lowest pathogen risk index (0.312, a 50.94% reduction).
• Croplands exhibited higher pathogen retention and more complex, fragmented microbial interaction networks, while green infrastructure promoted simpler, stable interactions.

Conclusions:

• Urban green infrastructure plays a crucial role in reducing soil-borne pathogen risks.
• Afforestation and constructed wetlands foster greater microbial diversity and community stability, contributing to improved urban ecosystem health.
• Findings provide actionable insights for sustainable land management and urban public health strategies.