Different plant species and their traits on methane (CH ₄ ) emission from wetlands of eastern Himalayan foothills

Background: Plant species can alter the characteristics of wetlands soils and thereby influence methane (CH4) flux and other greenhouse gas emissions. In addition, wetlands are important conduits of CH4 without plants and may emit CH4 at a higher rate when plants are present. In this study, we aimed to quantify the efficiency of Mikania micrantha, Phragmites karka, Polygonum hydropiperoides, Enhydra fluctuans, and Ipomoea aquatica plants, along with their respective traits, in mediating CH4 emissions from wetlands. Results: CH4 emissions have significantly differed amongst different plant species studied. Further, CH4 emission showed a strong and significant relationship with plant traits, soil physico-chemical, and biological properties. The average cumulative CH4 emission from all the vegetation stands (10.30 mg m-2 h-1) was significantly higher (118.08%) than that of the CH4 emission from unvegetated bare soil (4.70 mg m-2 h-1). Overall, the CH4 emission increased by 15%, 44%, and 37% under M. micrantha, P. karka, and P. hydropiperoides, respectively, compared with E. fluctuans and I. aquatica. Conclusions: Wetland plants could significantly alter the functions and services of wetlands and, cause CH4 emissions. Hence, we suggest that restoration of these wetlands with periodical eradication and proper reuse/utilization of these wetland plants would be appropriate to mitigate the CH4 emissions from the wetlands.