Rewiring biogeochemical interactions: How interbasin water transfers shape DOM-Microbe dynamics

Area of Science:

• Environmental Science
• Ecology
• Biogeochemistry

Background:

• Interbasin water transfers (IBTs) are large-scale projects altering inland hydrology and biogeochemical cycles.
• The impact of IBTs on dissolved organic matter (DOM) and microbial communities remains poorly understood.

Purpose of the Study:

• To investigate how IBTs rewire DOM-microbe coupling in hydrologically altered ecosystems.
• To elucidate the mechanisms driving these changes using advanced analytical techniques.

Main Methods:

• Utilized Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) for DOM characterization.
• Employed high-throughput sequencing to analyze microbial community composition.
• Applied network analysis to understand DOM-microbe interactions.

Main Results:

• IBTs altered DOM composition and microbial communities, increasing labile DOM by 70% in receiving waters.
• Receiving waters showed higher abundances of Cyanobacteriota and Actinomycetota.
• Rare microbial taxa played a significant role in DOM-microbe coupling, which was enhanced in IBT-receiving waters.

Conclusions:

• DOM molecular traits are key drivers of microbial community structure and DOM-microbe coupling under IBTs.
• IBTs significantly rewired DOM-microbe interactions, impacting biogeochemical cycling.
• Findings advance understanding of ecosystem responses to large-scale hydrological engineering.