457-2 The Influence of Eutrophication Status on the Kinetics of Methane Oxidation in Soils from a Subtropical Freshwater Wetland.

Poster Number 2027

See more from this Division: SSSA Division: Wetland Soils
See more from this Session: Wetland Soils: II (includes student competition)
Wednesday, November 5, 2014
Long Beach Convention Center, Exhibit Hall ABC
Share |

Francisca Ordonez Hinz, Soil and Water Science, Wetland Biogeochemistry Laboratory, University of Florida, Gainesville, FL, Lucy Ngatia, Soil and Water Science, University of Florida Agronomy & Soils Club, Gainesville, FL, Patrick W. Inglett, Department of Soil and Water Science, Wetland Biogeochemistry Laboratory, Gainesville, FL, K. Ramesh Reddy, Soil and Water Science Department, University of Florida, Gainesville, FL and Kanika S. Inglett, University of Florida, Gainesville, FL
Poster Presentation
  • FHinz SSSA 2014.pdf (1.4 MB)
  • Microbial methane (CH4) oxidation has potential to reduce up to 90% of CH4 emissions fluxed from wetland soils. Therefore, a greater understanding of the process of is essential to improve strategies to reduce CH4 emissions from wetland systems. A laboratory manipulation study was performed using microcosms containing soils which were collected from the eutrophic (F1) and oligotrophic ridge (U3R) and slough (U3S) sites of WCA-2A in Florida Everglades. The rates of CH4 oxidation were measured for each site along the depth profile at 0-5, 5-10, and 10-20 cm increments to determine the Michaelis-Menton kinetics. Significant differences were found in the maximum oxidation rate (Vmax) and oxidation affinity (Km) among the sites and with soil depth. The Vmax (20.14.7 g CH4 g-1 h -1) at 0-5 cm in F1 was significantly lower than deeper depths. The Vmax of F1 at 5-10 cm was significantly higher than U3R and U3S. The Km at 0-5 cm in F1 (684 313 g CH4 g-1) and U3R (1380 230 g CH4 g-1) showed significantly higher affinity than deeper depths. The Km values below 5 cm of U3S were significantly lower than both F1 and U3R. Significant positive correlations with total phosphorus (TP) suggest that TP may be influencing the oxidation activity. Correlations with nitrate (NO3-) suggest varying influence of NO3- on oxidation activity, with higher NO3- concentrations having an inhibitory effect on CH4 oxidation rates. In addition, phospholipid fatty acid analysis was performed to determine the fingerprint of the microbial community structure.
    See more from this Division: SSSA Division: Wetland Soils
    See more from this Session: Wetland Soils: II (includes student competition)