Ammonium-derived nitrous oxide is a global source in streams.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38744837.
- Also identified by DOI 10.1038/s41467-024-48343-9 and PMC identifier 11094135.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Global riverine nitrous oxide (N<sub>2</sub>O) emissions have increased more than 4-fold in the last century. It has been estimated that the hyporheic zones in small streams alone may contribute approximately 85% of these N<sub>2</sub>O emissions. However, the mechanisms and pathways controlling hyporheic N<sub>2</sub>O production in stream ecosystems remain unknown. Here, we report that ammonia-derived pathways, rather than the nitrate-derived pathways, are the dominant hyporheic N<sub>2</sub>O sources (69.6 ± 2.1%) in agricultural streams around the world. The N<sub>2</sub>O fluxes are mainly in positive correlation with ammonia. The potential N<sub>2</sub>O metabolic pathways of metagenome-assembled genomes (MAGs) provides evidence that nitrifying bacteria contain greater abundances of N<sub>2</sub>O production-related genes than denitrifying bacteria. Taken together, this study highlights the importance of mitigating agriculturally derived ammonium in low-order agricultural streams in controlling N<sub>2</sub>O emissions. Global models of riverine ecosystems need to better represent ammonia-derived pathways for accurately estimating and predicting riverine N<sub>2</sub>O emissions.
Medical subject headings
- Nitrous Oxide
- Rivers
- Ammonium Compounds
- Bacteria
- Ecosystem
- Ammonia