Relationships between CH₄ emission, biomass, and CO₂ exchange in a subtropical grassland

Methane flux was linearly correlated with plant biomass (r = 0.97, n = 6 and r = 0.95, n = 8) at two locations in a Florida Everglades Cladium marsh. One location, which had burned 4 months previously, exhibited a greater increase in methane flux as a function of biomass relative to sites at an unburned location. However, methane flux data from both sites fit a single regression (r = 0.94, n = 14) when plotted against net CO₂ exchange suggesting that either methanogenesis in Everglades marl sediments is fueled by belowground root exudation or else factors which enhance photosynthetic production and plant growth are also correlated with methane production and flux in this oligotrophic environment. -from Authors