Coupled N and P cycling as driven by microbial taxa and interactions

Area of Science:

• Ecology
• Microbiology
• Environmental Science

Background:

• The coupled cycling of nitrogen (N) and phosphorus (P) is crucial for ecosystem function.
• Understanding the microbial players and interactions in N-P coupling and decoupling is limited.
• This study investigates microbial communities in a unique natural laboratory exhibiting both coupled and decoupled N-P cycling.

Purpose of the Study:

• To identify specific microbial taxa (bacteria and fungi) involved in N-P coupling and decoupling.
• To explore the interactions between these microbial taxa and their relationship with N-P cycling variables.
• To elucidate the roles of microbial communities in promoting or hindering N-P coupling in forest ecosystems.

Main Methods:

• Utilized amplicon sequencing to analyze bacterial, fungal, and phoD-harboring communities.
• Correlated microbial community data with N and P cycling variables in coupled and decoupled sites.
• Constructed microbial interaction networks to compare coupled and decoupled taxa.

Main Results:

• Identified 14 phyla and 68 genera as 'coupled taxa' correlated with both N and P cycling.
• Discovered specific coupled taxa (e.g., Nitrospirota, Candidatus Koribacter) enriched in coupled sites, promoting N-P coupling.
• Found that coupled microbial networks exhibit more positive interactions, while decoupled networks show more negative interactions, influencing N-P dynamics.

Conclusions:

• Coupled microbial taxa, through individual action and synergistic interactions, enhance N-P coupling.
• Decoupled microbial taxa, through individual action and antagonistic interactions, facilitate N-P decoupling.
• These findings provide insights for managing nutrient cycling in forest ecosystems facing environmental change.