Methane emission and plant transport capacity of different vegetation types in lake wetlands in the middle reaches of the Yangtze River
Lakes are an important source of atmospheric methane(CH4).However,the impacts of plant types and alien plant invasion on CH4 emissions in lakes are insufficiently investigated.In this study,four sites including open water,floating plant(Trapa natans),emergent plant(Zizania latifolia),and invasive plant(Eichhornia cras-sipes)regions were selected in the Honghu Lake in the middle reaches of the Yangtze River.The concentration of CH4 was measured using a floating chamber and gas chromatography method from May to October,2022.There were temporal variations of CH4 emission fluxes at the four sites.The CH4 emission fluxes ranged from 0.10 to 136.12 mg·m-2·h-1,with the peak values presenting in summer or autumn.The mean CH4 emission fluxes were 1.68,4.52,4.58,and 28.59 mg·m-2·h-1 at the open water,floating plant,emergent plant,and invasive plant sites,respectively.The CH4 emission fluxes of three sites with plants were 2.7 to 17 times than that of the open water.The CH4 emission fluxes from the site with invasive plant was 6.2,6.3,and 17 times that of the emergent plant,floating plant,and open water sites,respectively.These results could be attributed to the massive plant bio-mass,more effective plant-mediated transport of CH4,and higher soil organic carbon content in the invasive plant site.The plant-mediated transport of CH4 at the three sites dominated by Zizania latifolia,Trapa natans,and Eich-hornia crassipes were 0.02,0.23,and 0.25 mg·m-2·h-1,respectively,indicating that Eichhornia crassipes was most efficient in CH4 transport.Our results suggest that CH4 emission fluxes derived from the invasive plants would be strengthened in the Honghu Lake in the middle reaches of the Yangtze River,which could be a positive feedback on climate change.
lake wetlandmethane emissionplant typeplant invasion
万方数据
维普
