are a result of seasonal variations in methane-consuming and methane-producing microbial communities
Wetland ecosystems are the most important and prolific natural methane (CH4) sources. CH4 is constantly flowing in and out of these regions (flux), and that flow periodically fluctuates. Methanogens (methane producers) and methanotrophs (methane consumers) are microorganisms that influence CH4 fluxes in wetlands. The mutual or symbiotic relationship of methanogens to methanotrophs is not clear. Biologists and atmospheric scientists see a critical opportunity to explore methanogen and methanotroph population co-occurrence patterns and their influences on natural CH4 fluxes.
Prof. Jiwen GE and his team members representing the Laboratory of Basin Hydrology and Wetland Eco-Restoration, the Wuhan/Hubei Key Laboratory of Wetland Evolution and Ecological Restoration, and the Wuhan/Institution of Ecology and Environmental Sciences, of the China University of Geosciences, Wuhan, studied the variables that influence seasonal variations between methanogenic and methanotrophic community influence on wetland CH4 emissions. Through biological (phylogenetic) network analysis, they identified a keystone species that plays a pivotal role in mediating CH4 fluxes. Their full study is now available in Advances in Atmospheric Sciences.
The team adapted an eddy-covariance (EC), system that studies microclimatological gas exchange in order to analyze seasonal methane flow data. EC systems are capable of long-term (years or even decades) CH4 flux measurements without disturbing the surrounding environment. Then, they identified the keystone CH4 mediating microorganism species using phylogenetic molecular ecological networks (pMENs) analysis, which biologists typically use to determine a group of organisms’ evolutionary development and their features.
The researchers used the methanogenic pMENs and the methanotrophic PMENs to examine how methanogenic communities function season-to-season. Along with pMENs, they used correlation analysis methods to demonstrate the interrelationships among several environmental factors, including methane metabolic microbials and CH4 fluxes.
The study provided substantial evidence that explains the seasonal patterns and microbial driving mechanisms of CH4 emissions in wetlands. These data can be used to support wetlands management in these biodiverse areas and for sustainable, carbon neutral development.
To prepare for future research, the team calculates and analyzes methane fluxes over longer-term periods (five to ten years). To analyze the effects of microbials and methane fluxes, more research is required that involves metagenomic sequencing (multiple organism communities).