|| 要旨トップ | 目次 |||日本生態学会第68回全国大会 (2021年3月、岡山) 講演要旨
一般講演（ポスター発表） P1-260 （Poster presentation）
Coastal wetlands serve an important role in nitrogen (N) and greenhouse balances, but are recognized as a significant source of N₂O. Currently, they are exposed to rapid environmental changes, including increased N load and salinization associated with atmospheric depositions, agricultural runoff, and sea-level rise. We conducted a laboratory incubation experiment for 10 days, using soils from both saltwater and freshwater wetlands. We applied the full factorial combination of treatments with three levels of N (0, 50, 150 μgN g−1) and two levels of salt (0 and 30 ppt). We measured soil N₂O emissions, inorganic N concentrations, and DOC concentrations before and 1, 3, 5, 7, and 10 days after the treatments. Before the treatments, N₂O fluxes were negative in both soils, indicating potential sinks of N₂O in low N availability. In high salinity soils, N additions enhanced N₂O emissions regardless of the salt levels, suggesting N being a limiting factor for N2O production. In low salinity soils, saltwater additions decreased both N₂O emissions and DOC concentrations, implying inhibited denitrification due to lack of microbial energy sources. Our findings suggest in the short-term, changes in N load and salinity could influence N₂O balances in coastal soils depending on their initial salinity.