13:45 〜 14:00
[BCG04-01] Microbial mechanism for the diverse responses of methane dynamics to nitrogen enrichment in soil ecosystems
★Invited Papers
キーワード：Microbial community, Methane oxidation, Meta-analysis
Nitrogen (N) serves as a critical limiting factor in numerous soil ecosystems, exerting a substantial influence on the global carbon cycle. Recent studies indicate an increase in nitrogen availability across soil ecosystems, driven by accelerated N mineralization, N deposition, and N fertilization. While extensive research has explored the implications of these changes on primary production and N2O emissions, there is a notable gap in synthesizing information concerning methane (CH4) dynamics, the second most potent greenhouse gas with an unresolved global budget.
This study aims to contribute a novel perspective on the impacts of N enrichment on soil microbes responsible for mediating CH4 oxidation and production by employing a comprehensive approach encompassing global meta-analysis, manipulation experiments, and field observations. Our meta-analysis revealed a diverse range of responses in CH4 oxidation following nitrogen additions, with a near-zero response ratio. Notably, nitrogen additions are found to enhance CH4 oxidation in rice paddies and landfill sites, whereas an opposing trend is observed in tundra, forests, and dry farms.
Our manipulation experiment in dry tundra demonstrates a significant reduction in CH4 oxidation with NO3- additions, while a parallel experiment in rice paddies shows varied responses linked to soil chemical properties such as total nitrogen content. Microbial community analysis further suggests that nitrogen additions alter the relative abundances of different types of methanotrophs, contributing to the diverse responses in CH4 oxidation following nitrogen additions. We hypothesize that microbial composition and activity, along with interactions among different functional groups, may play a pivotal role in determining the responses in CH4 dynamics induced by nitrogen enrichment in soil ecosystems. The findings offer valuable insights into the intricate interplay between nitrogen availability, microbial communities, and methane dynamics, ultimately contributing to a more comprehensive understanding of how ecosystems respond to nitrogen enrichment.
This study aims to contribute a novel perspective on the impacts of N enrichment on soil microbes responsible for mediating CH4 oxidation and production by employing a comprehensive approach encompassing global meta-analysis, manipulation experiments, and field observations. Our meta-analysis revealed a diverse range of responses in CH4 oxidation following nitrogen additions, with a near-zero response ratio. Notably, nitrogen additions are found to enhance CH4 oxidation in rice paddies and landfill sites, whereas an opposing trend is observed in tundra, forests, and dry farms.
Our manipulation experiment in dry tundra demonstrates a significant reduction in CH4 oxidation with NO3- additions, while a parallel experiment in rice paddies shows varied responses linked to soil chemical properties such as total nitrogen content. Microbial community analysis further suggests that nitrogen additions alter the relative abundances of different types of methanotrophs, contributing to the diverse responses in CH4 oxidation following nitrogen additions. We hypothesize that microbial composition and activity, along with interactions among different functional groups, may play a pivotal role in determining the responses in CH4 dynamics induced by nitrogen enrichment in soil ecosystems. The findings offer valuable insights into the intricate interplay between nitrogen availability, microbial communities, and methane dynamics, ultimately contributing to a more comprehensive understanding of how ecosystems respond to nitrogen enrichment.