[Short-term Effects of Nitrogen Deposition on CO₂ and CH₄ Fluxes from Wetlands in the Minjiang River Estuary]

In order to evaluate the effects of nitrogen deposition on CO₂ and CH₄ fluxes from a Cyperus malaccensis marsh in the Min River estuary at Daoqingzhou, Fujian, static chamber-gas chromatography (GC) techniques were used. CO₂ and CH₄ fluxes at a control (CK)[0 g·(m²·a)^-1], N1[24 g·(m²·a)^-1], N2[48 g·(m²·a)^-1], and N3[96 g·(m²·a)^-1] were measured and analyzed and the related environmental factors were recorded. The results show that,① compared to the control treatment, the effects of nitrogen deposition on the CO₂ fluxes for N1 and N3 increased by 20.30% and 4.06%, respectively, whereas the CO₂ fluxes for N2 reduced by 10.05%, furthermore, the CO₂ fluxes under different treatments were not significantly different (P>0.05), except for the N2 and N3 treatments in December (P<0.05). ② Compared to the control treatment, the effects of nitrogen deposition on CH₄ fluxes at N1, N2, and N3 were increased by 64.51%, 30.23%, and 80.57%, respectively, whereas the CH₄ fluxes under different treatments were not significantly different (P>0.05). ③ There was significant positive correlation between CO₂ and CH4 fluxes and soil temperature (P<0.05), however, the CO₂ and CH₄ fluxes were not significant with regards to soil pH and soil EC (P>0.05).