Long-Term Nitrogen Addition Eliminates the Cooling Effect on Climate in a Temperate Peatland

Peatlands play a crucial role in global carbon (C) sequestration, but their response to long-term nitrogen (N) deposition remains uncertain. This study investigates the effects of 12 years of simulated N addition on CO<sub>2</sub> and CH<sub>4</sub> fluxes in a temperate peat...

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Bibliographic Details
Main Authors: Fan Lu, Boli Yi, Kai Qin, Zhao-Jun Bu
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Plants
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Online Access:https://www.mdpi.com/2223-7747/14/8/1183
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Summary:Peatlands play a crucial role in global carbon (C) sequestration, but their response to long-term nitrogen (N) deposition remains uncertain. This study investigates the effects of 12 years of simulated N addition on CO<sub>2</sub> and CH<sub>4</sub> fluxes in a temperate peatland through in situ monitoring. The results demonstrate that long-term N addition significantly reduces net ecosystem exchange (NEE), shifting the peatland from a C sink to a C source. This transition is primarily driven by a decline in aboveground plant productivity, as <i>Sphagnum</i> mosses were suppressed and even experienced mortality, while graminoid plants thrived under elevated N conditions. Although graminoid cover increased, it did not compensate for the GPP loss caused by <i>Sphagnum</i> decline. Instead, it further increased CH<sub>4</sub> emissions. These findings suggest that sustained N input may diminish the C sequestration function of peatlands, significantly weakening their global cooling effect.
ISSN:2223-7747