Methane emissions from emergent aquatic macrophytes

Aquatic plants can function as conduits for methane from sediment to the air, and thus contribute to the global methane balance. In a recent Editor’s Choice article published in AoB PLANTS, Milberg et al. studied the flux of methane from plots, in two Swedish lakes, dominated by two species (Phragmites australis, Carex rostrata). There were substantial seasonal differences (June to October), mainly tracking air temperature. There were large differences in flux during 24 hour sampling, but with no consistent patterns between days. Emissions per square metre were similar for the two species. This suggests a system where methane production shapes emissions while species identity, and diurnal patterns, play a smaller role. Further evaluation is now required to support improved local and regional methane flux assessments.