Exceptional methane emissions from an African papyrus wetland
The Mpologoma papyrus wetland emits 720.5 ± 378.7 mg CH₄ m⁻² d⁻¹, representing a significant contribution to global methane emissions.
Where it sits
this study against the rest of the pe 22-28 corpusSummary and findings
This study measured methane emissions from the Mpologoma papyrus wetland in Uganda over a 25-month period. The wetland emitted 720.5 ± 378.7 mg CH₄ m⁻² d⁻¹, which is reported as the highest persistent methane emissions recorded from a wetland. The findings suggest significant contributions to global methane budgets from this wetland type.
Abstract
<title>Abstract</title> <p> Tropical wetlands are major natural methane sources <sup>1-3</sup> , yet long-term ecosystem-scale measurements remain extremely scarce across Africa <sup>4,5</sup> , limiting their attribution and representation in methane budgets and models <sup>4-8</sup> . Here we present the highest persistent methane emissions ever recorded from a wetland. We combine a 25-month eddy-covariance record spanning nearly three years at the permanently flooded Mpologoma papyrus wetland in Uganda with chamber measurements, microbial profiling and satellite-derived phenology. Mpologoma emitted 720.5 ± 378.7 mg CH₄ m⁻² d⁻¹, surpassing all published natural-wetland eddy-covariance records in sustained mean flux and seasonal peak. Its mean flux was more than twice the next-highest value, and its seasonal peak nearly three times higher. Our results reveal a different process hierarchy: phenology-controlled methane variability; hydrology modulated this control; microbial communities underpinned methane production and oxidation; and soil/water fluxes constitute the dominant methane-emission pathway to the atmosphere. This process-level understanding provides the missing link between methane signals detected by satellites and atmospheric inversions <sup>2,9-15</sup> , the ecosystems producing them <sup>4,16-18</sup> , and the mechanisms Earth-system models must represent <sup>11,19-21</sup> . Applying Mpologoma’s flux to four million hectares of East African papyrus wetlands yields 10.5 Tg CH₄ yr⁻¹—nearly 7% of global wetland emissions— revealing that a single wetland type could reshape the global methane budget. </p>
Background
Not reported in abstract.
Methods
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Results
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Interpretation
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Limitations
- Not reported in abstract.