Attenuation of Methane Oxidation by Nitrogen Availability in Arctic Tundra Soils

Abstract

CH4 emission in the Arctic has large uncertainty due to the lack of mechanistic understanding of the processes. CH4 oxidation in Arctic soil plays a critical role in the process, whereby removal of up to 90% of CH4 produced in soils by methanotrophs can occur before it reaches the atmosphere. Previous studies have reported on the importance of rising temperatures in CH4 oxidation, but because the Arctic is typically an N-limited system, fewer studies on the effects of inorganic nitrogen (N) have been reported. However, climate change and an increase of available N caused by anthropogenic activities have recently been reported, which may cause a drastic change in CH4 oxidation in Arctic soils. In this study, we demonstrate that excessive levels of available N in soil cause an increase in net CH4 emissions via the reduction of CH4 oxidation in surface soil in the Arctic tundra. In vitro experiments suggested that N in the form of NO3 – is responsible for the decrease in CH4 oxidation via influencing soil bacterial and methanotrophic communities. The findings of our meta-analysis suggest that CH4 oxidation in the boreal biome is more susceptible to the addition of N than in other biomes. We provide evidence that CH4 emissions in Arctic tundra can be enhanced by an increase of available N, with profound implications for modeling CH4 dynamics in Arctic regions.

Metabolic coupling between soil aerobic methanotrophs and denitrifiers in rice paddy fields

“…However, no such enrichment of 13 C-labeled metabolites was observed in the red soil, where methanotrophs were predominantly composed of (over 90%) type II methanotrophs. Previous studies have reported that type II methanotrophs, including Methylocystis and Methylosinus , were less tolerant to high N concentration 47 , 48 . Therefore, the effects of NO 3 − on methanotrophs may exert confounding effects on the coupling between CH 4 oxidation and denitrification.…”

Bridge-type Mn–O–Mn sites promoting catalytic methane oxidation and carbonate desorption over Mn-based oxides

“…Natural gas has been widely used as an energy source in vehicles or power plants. [1][2][3] Catalytic methane (CH 4 ) as a greenhouse gas is the main component of natural gas, which causes serious harm to the environment. 4,5 In response to the premise that the country strongly advocates carbon neutrality, it is urgent to effectively eliminate CH 4 emission.…”