PhD Oral Defence: Carbon cycling at a post-extraction restored peatland: Small-scale processes to global climate impacts
PhD Oral Defence of Kelly Nugent, Natural Resource Sciences
The global scale of peatland loss, drainage and use is worrisome as peatlands, when undisturbed, perform an essential function of removing CO2 from the atmosphere, which has a cooling impact on the climate. A large amount of funding has recently been put toward restoring peatlands, in the hopes of returning lost ecological services, including climate regulation. Of the restoration sites studied, most were less than a decade old and none were consistent annual carbon sinks. The timeframe needed for carbon functioning to re-establish is practical knowledge that is needed to justify and improve restoration practices. In this thesis, I have determined the timeframe and net climate impact of re-establishing a carbon sink at an actively rewetted and revegetated post-extraction peatland. Findings from this study demonstrated that re-establishing key peatland species and integrating structures to increase water retention are effective at re-establishing the net carbon sink rate to that of an undisturbed peatland within a decade and a half. The legacy of cutover peat in reducing CH4 production and thus emission helps increase carbon accumulation in the short-term while also reducing the climate warming impact of the restored site during the transition to a carbon sink. An industry after-use plan that includes prompt active restoration is most effective at reducing the climate impact of a post-extraction site and is key to utilizing peatland restoration as a climate change mitigation strategy.