Ecological restoration of post-extracted peatland in Canada. A comparative approach of the vegetation community between restored and natural peatland

Canada is a leading producer, and exporter of peat used for horticultural purposes. Nevertheless, in that context, peat extraction requires the removal of vegetation and the drainage of Sphagnum-dominated peatlands causing disturbances of hydrological regimes and the disappearance of biodiversity as well as most ecosystems services. Moreover, when peat extraction is over, the formerly extracted peatlands become a source of greenhouse gases due to the oxidation of residual peat. Without human intervention, horticultural post-extracted peatlands will almost never return to their original pre-disturbance state. In order to solve this ecological problem, the Peatland Ecology Research Group (PERG) developed in the late 1990s an active ecological restoration method better known as the Moss Layer Transfer Technique (MLTT). Thus, the MLTT allows not only to restore the specific hydrology, but also to restore the Sphagnum carpet as well as typical peatland vegetation communities. Given the effectiveness of the MLTT to restore Sphagnum-dominated peatlands in a short period of time, it is now necessary to clarify and define the notion of a successful peatland restoration work. To achieve this, the present research project uses a fundamental tool of the science of ecological restoration embodied by the reference ecosystem. Consequently, the use of a reference set perform by natural peatlands makes it possible, through the intermediary of the vegetation communities, to appreciate the similarity or the ecological distance of the restored peatlands according to the time up since the restoration. This research work thus underlines the capacity of the MLTT to restore functional peatlands ecosystems on the basis of certain foundations taught by ecological restoration in the context of global climate change and erosion of biodiversity.