SOIL ORGANIC CARBON IN A WETLAND INTERRUPTED BY A CENTURY OF AGRICULTURE

Wetlands host a great diversity of biogeochemical processes that regulate water quality, soil organic carbon (SOC) content, and biogenic greenhouse gas (GHG) emissions to the atmosphere. US governmental agencies have established policies to protect and increase the numbers of wetlands. Simultaneously, policy makers are considering directives to mitigate increases in atmospheric GHG. Wetlands are well-established sinks for CO₂ and sources of methane (CH₄), a potent greenhouse gas with 34 times the radiative forcing of CO₂. However, the net GHG emission from wetlands is uncertain. This makes it imperative to understand the interaction between policies aimed at both wetland restoration and climate mitigation. Therefore, we ask: Is restoring agricultural lands to wetlands synergistic or antagonistic with the goals of climate change mitigation? To investigate this question we are studying the GHG balance of the initial phases of construction of a wetland in southwest Ohio. Construction activities uncovered histosols on the site indicating this is a wetland interrupted by ca. 120 years of agriculture. The loss of SOC during the agricultural phase of this wetland and the potential to regain that SOC will be the focus of this paper.