This Research program examined the importance of autochthonous versus allochthonous plant sources of dissolved organic carbon (DOC) to wetlands and how the DOC is progressively degraded under dynamic environmental conditions. UV-B photolysis of dissolved organic compounds is an important mechanism that enhances the availability of plant organic carbon to both aerobic and methaogenic bacteria and increases releases of CO₂ and CH₄. Temporal and spatial variations in flooding are critical to composite estimations of methane evasion rates.