Abstract: Background, aim, and scope Taken the Spartina alterniflora Loisel marsh in Minjiang River Estuary as the research area, the effects of crabs on soil CO2, CH4, N2O emission fluxes and the integrative warming were determined by the combined method of static box and gas chromatography on January (winter), April (spring), June (summer) and September (fall) of 2015. Materials and methods Based on Origin 8.0 and SPSS 20.0 software, the differences in soil temperature, pH, EC, and water content with different CO2, CH4 and N2O emission fluxes were analyzed. Correlation between emission fluxes of CO2, CH4 and N2O and environmental factors using Pearson correlation analysis. Results The research showed that seasonal change in greenhouse gas emission are more significant, and the maximum CO2 and CH4 emission fluxes appear in summer, and the maximum N2O emission flux appears in the fall, and the minimum fluxes of CO2, CH4 and N2O emissions appear in the spring. The mean values of CO2, CH4 and N2O emission fluxes in the high-tide flat and the middle-tidal flat crab groups were increased compared with the non-crab group, and the soil CO2, CH4 and N2O emission fluxes of high-tide flat crab group were increased by 46.36%, 66.67% and 69.66%, and the soil CO2, CH4 and N2O emission fluxes in the middle-tidal flat crab group were increased by 53.57%, 142.97% and 73.08%. The results of correlation analysis revealed that soil CO2 emission fluxes were significantly and positively correlated with soil temperature (n=96, p<0.05), and the CH4 and N2O emission fluxes were significantly and positively correlated with soil temperature (n=96, p<0.01). The N2O emission fluxes were significantly and positively correlated with soil pH (n=96, p<0.01), and were positive and correlation with the soil water content (n=96, p<0.05). Discussion Carb activity directly or indirectly interfered with soil properties (pH, aeration, particle composition, etc.) and had a greater impact on wetland greenhouse gas emissions. Conclusions The disturbance of crab activities on the soil of Spartina alterniflora Loisel marsh in Minjiang River estuary promoted the increase of greenhouse gas emissions; Soil temperature was the main environmental factor affecting greenhouse gas emissions from wetlands. Recommendations and perspectives Crab activity can influence the dynamic change of greenhouse gas emissions from wetlands from a new perspective, and provided reference for effectively regulating the carbon and nitrogen retention of wetlands and wetland ecosystem science management.
Keywords: crab; greenhouse gas; Spartina alterniflora Loisel marsh; Minjiang River estuary