Elevated ground-level O3 negatively influences paddy methanogenic archaeal community

Area of Science:

• Environmental Science
• Microbiology
• Climate Change Research

Background:

• Global climate change impacts ecosystems, yet the effect of elevated ground-level ozone (O3) on rice-paddy methane (CH4) emissions remains unclear.
• Understanding microbial responses to O3 is crucial for predicting CH4 emissions from rice paddies.

Purpose of the Study:

• To investigate the impact of elevated ground-level ozone (O3) on methanogenic archaeal communities in a rice-wheat rotation system.
• To elucidate the mechanisms of microbial response to O3 concerning methane production in paddy fields.

Main Methods:

• Field experiment using the China Ozone Free-Air Concentration Enrichment (O3-FACE) facility.
• Culture-independent and culture-reliant approaches were employed to analyze methanogenic archaeal communities.
• Assessment of methanogenic activity and community composition under elevated O3 conditions.

Main Results:

• Elevated ground-level O3 significantly inhibited methanogenic activity in rice paddies.
• O3 altered the composition of methanogenic archaeal communities, reducing abundance and diversity.
• Dominant methanogen groups, particularly aceticlastic Methanosaeta, were adversely affected, especially during the rice tillering stage.

Conclusions:

• Continuous exposure to elevated ground-level O3 negatively influences paddy methanogenic archaeal communities and their ecological functions.
• These findings highlight a critical feedback loop between O3 pollution and CH4 emissions, impacting global climate change.
• The study contributes to a more comprehensive understanding of paddy ecosystem responses to global environmental changes.