Microbial Community Functional Potential and Composition Are Shaped by Hydrologic Connectivity in Riverine Floodplain...

Area of Science:

• Environmental microbiology
• Soil science
• Ecosystem ecology

Background:

• Riverine floodplains are vital ecosystems facing threats from human activities.
• Microbial communities in floodplain soils are crucial for biogeochemical processes.
• The link between microbial communities and hydrologic connectivity remains poorly understood.

Purpose of the Study:

• To investigate the relationship between soil microbial communities and hydrologic connectivity in riverine floodplains.
• To determine how land management and topography influence microbial community structure and function.
• To understand the impact of hydrologic connectivity on biogeochemical processes mediated by soil microbes.

Main Methods:

• Metagenomic analysis of microbial communities in three distinct floodplain soils.
• Assessment of long-term hydrologic connectivity gradients.
• Analysis of soil properties including organic matter and nitrogen content.

Main Results:

• Microbial communities varied significantly along a hydrologic connectivity gradient.
• Strictly anaerobic taxa and pathways increased with hydrologic connectivity and flooding frequency.
• Aerobic taxa and pathways decreased with increased connectivity; genetic potential for organic matter metabolism declined.

Conclusions:

• Soil microbial community structure in riverine floodplains can be understood along a hydrologic connectivity gradient.
• Flooding frequency, soil organic matter, and soil nitrogen are key drivers shaping these microbial communities.
• Findings are crucial for managing and restoring microbially mediated biogeochemical processes in floodplain wetlands.