2025/09/02 by Yinghuan Qin, Kajsa Roslund, Amy Samantha Smart +2 · 2 voices · 2 citations
Environmental Science · Earth and Planetary Sciences · #Peatlands and Wetlands Ecology #Atmospheric chemistry and aerosols #Integrated Water Resources Management
paper · pdf · doi:10.1002/lno.70202
Abstract The role of small water bodies in global carbon emissions is increasingly acknowledged. In addition to the well‐investigated greenhouse gases, carbon dioxide (CO 2 ) and methane, volatile organic compounds (VOCs) may be emitted from freshwater ecosystems, especially from small water bodies, but the composition of emitted VOCs and emission magnitudes remain largely undescribed. Referring to empirical great contributors of freshwater greenhouse gases, we assessed seasonal VOC emissions from three carbon and nutrient‐rich ponds in a peatland forest in Denmark. These ponds were CO 2 emitters throughout the sampling period (19.5 ± 67.7 to 396.8 ± 120.0 mg m −2 h −1 ). The total net fluxes of > C5 VOCs measured in situ ranged from 7.8 ± 1.4 to 95.3 ± 4.5 μ g m −2 h −1 and over one hundred compounds were detected. The emissions consisted mainly of hydrocarbons, oxygenated VOCs, and terpenoids (isoprene, monoterpenoids, and sesquiterpenoids). We found the in situ VOC fluxes and compositions varied with season and were positively correlated with chamber temperature. These fluxes also differed between ponds and were related to the chemical properties of pond water. Additionally, we observed emissions of significant and various lighter VOCs (< C5) and sulfur/nitrogen‐containing compounds in complementary lab measurements and demonstrated again the temperature dependence and pond‐to‐pond heterogeneity of VOC emissions. Overall, our findings indicate natural eutrophic ponds are net VOC sources. The significance of these emissions for carbon budgets and atmospheric impact requires future research.