Methane emission in constructed wetland with/without emerged plant

Abstract

To investigate the effect of plant presence/absence and plant species on the methane emission, we established three treatments by using two different plant species in microcosms of constructed wetlands. Results showed that methane emission and carbon removal efficiency were significantly difference among the 3 treatments (P < 0.001). The methane emission (P < 0.001) and microbial biomass (P < 0.01) in the planted microcosms were higher than in those unplanted treatment, but total organic carbon (P < 0.001) concentrations in effluents were lower. The methane emission and total organic carbon had no significant difference between those microcosms planted with Phragmites australis and Typha orientalis (P > 0.05). Although the aboveground and belowground biomass in the microcosms planted with Phragmites australis (P < 0.05) was lower than that in the microcosms planted with Typha orientalis, the shoot height of Phragmites australis was higher than Typha orientalis (P < 0.001). Hence, our study highlights the importance of plant presence/absence and plant species in mediating methane emission intensity in CWs.