METHANE DYNAMICS IN RESTORED AND CONSTRUCTED AGRICULTURAL WETLANDS

Wetlands provide valuable ecosystem services like nutrient retention and carbon sequestration and are thus recognized as potential nature-based solutions for regions that could benefit from such services. There has been policy-driven creation or restoration of wetlands on agricultural lands of southwestern Ontario to help mitigate nutrient runoff into Lake Eerie and the now regular occurrence of harmful algal blooms. While many of these wetlands have proven to efficiently limit nutrient runoff in the greater Lake Eerie watershed, the trade-off of these wetlands being significant methane emitters has not adequately been assessed. Here we thoroughly investigate methane dynamics in 18 restored or constructed wetlands in southwestern Ontario, focusing on the spatial and temporal variability of methane emissions as well as constraining methane oxidation – the primary consumptive process of this potent greenhouse gas. Using multiple oxidation models along with the carbon and hydrogen isotopic fractionation of methane, we reveal the extent of oxidation in these shallow, eutrophic, polymictic manmade waterbodies. Understanding the consumption of methane in these purposely made systems is crucial for a comprehensive conceptual model of their ecosystem functioning as a nature-based solution.

Presentation Preference: Oral

Primary Presenter: Tonya DelSontro, University of Waterloo (tdelsontro@gmail.com)

Authors:

Shayna Meinzinger, University of Waterloo  (sbmeinzinger@uwaterloo.ca)

Sara Abate, University of Waterloo  (Sabate@uwaterloo.ca)

Nandita Basu, University of Waterloo  (nandita.basu@uwaterloo.ca)

Richard Elgood, University of Waterloo  (rjelgood@uwaterloo.ca)

Sherry Schiff, University of Waterloo  (sschiff@uwaterloo.ca)