Plants passing gas: Plant traits and greenhouse gas emissions from a North Carolina restored wetland

Although natural wetlands make up only 4-6% of global land area, they have disproportionately large impacts on the global carbon cycle and on greenhouse gas (CO₂, CH₄, and N₂O) emissions. Wetland plants can influence emissions by controlling inputs of resources such as soil organic matter and by influencing abiotic conditions such as oxidation-reduction potential. Plant traits could potentially affect soil greenhouse gas emissions through 4 major chemical pathways: carbon (C) quantity, C quality & nitrogen (N) quantity, oxygen (O), and water (H₂O). Carbon quantity-related traits include photosynthetic rate and above- and belowground biomass; C quality and N-related traits include above- and belowground C:N ratios and specific root length; O-related traits include root porosity; and H­₂O-related traits include transpiration rates. We examine the relationship between plant traits and gas emissions at a 2-year old experimental restored wetland in Durham, North Carolina. The 2 m by 2 m plots each include 100 individuals, representing 1, 4, or 8 of 10 native herbaceous species; these species have simultaneously had the listed traits measured as continuous variables under greenhouse conditions. Accounting for environmental conditions such as soil moisture and soil inorganic N, preliminary measurements of potential soil CO₂ emissions from lab incubations (n=46) do not indicate significant correlations between CO₂ emissions and any plant traits at this site. Field measurements of CO₂, CH₄, and N₂O emissions will further explore these potential relationships between plant traits and soil biogeochemical processes.