Successes and Failures of Two Mire Restoration Projects. Are the goals met?

Peatlands cover about three percent of earth’s land surface in primarily the northern hemisphere and store an estimated 550 Gigatons of carbon. Peat is the substance formed when organic matter cannot completely decompose due to waterlogged and anoxic conditions. Under these circumstances, peat-lands have sequestered carbon for thousands of years. The construction of ditches to drain mires causes hydrological changes resulting in the drying of the peat which can then be harvested. The dry-ing and removal of peat layers destroys habitat and disables vegetation growth and thus peat accumu-lation. Furthermore, carbon sequestration function is destroyed. Large scale restoration efforts have not been achieved and long-term restoration successes cannot yet be evaluated. Additionally there has not been an evaluation of the collective impact of mire resto-ration measures. This study aims to determine whether peatland restoration projects meet their goal setting and contribute to re-establish peatland ecosystems and their function in the global carbon cycle and in contribution to biodiversity, by assessing factors that contribute to successes and failures. Therefore, literature research is undertaken to investigate (1) what the restoration techniques are, (2) what successes and failures of restoration can be distinguished, and (3) if efforts meet the goals of restoration of restoration projects undertaken in Canada and Ireland. The evaluation of measures taken at the Canadian and Irish restoration sites were found to take a whole ecosystem approach, focusing on all aspects of a mire ecosystem- hydrology, vegetation, peat accumulation, carbon flux, and biodiversity which is why they were chosen. One project in each country was chosen due to time constraints and the limited number of evaluation studies available. The main measure taken to restore mires is the blocking of drainage ditches which should aid in re-turning hydrological conditions necessary for vegetation establishment and peat accumulation. To investigate if the measures taken reach the goal of restoration, changes to hydrology, biodiversity, and carbon flux of two restoration projects were investigated. At the Bois-des-Bel Bog in eastern Canada restoration measures were carried out, including blocking of drainage ditches, construction of em-bankments, plant fragment spreading, fertilization, and straw mulch application. At Camderry Bog in central Ireland restoration measures included clear felling and embankment of the area and blocking of drainage ditches using peat dams. The goal of restoring Bois-des-Bel Bog is the re-establishment of a self-regulating peat accumulating ecosystem. Camderry bog is restored with the goal to restore threatened raised bog habitats to a favourable status. The pre-restoration conditions of the sites dif-fered in terms of naturally established vegetation. While Bois-des-Bel was nearly void of vegetation, Camderry Bog showed some Sphagnum coverage, indicating favourable conditions for mire-typical vegetation establishment. At both sites water table level and vegetation coverage were monitored. At Bois-des-Bel monitoring was more comprehensive compared to Camderry Bog. At both sites the res-toration measures taken resulted in a raised water table level but increased seasonal fluctuations. Vegetation coverage had significantly increased; however, non-typical mire vegetation is competing with mire-typical vegetation. Amphibian and bird diversity and abundance had increased at Bois-des-Bel bog where artificial pools created habitat and breeding grounds. Although some fungal activity was observed there appears to be a lag time between vegetation establishment and microorganism re-covery. The carbon sequestration function was not restored. It was concluded that although the indi-vidual objectives of restoration such as raising the water table and establishing vegetation coverage were achieved, the overall goal was not. Restoration measures did not lead to a self-regulating peat accumulating ecosystem at Bois-des-Bel. The goal for Camderry Bog is too ambiguous to determine whether it was met and clarification of “favourable status” is needed. Although these results may not be representative for all bog restoration efforts, they may have implications for future use of pristine bogs; their conservation may be the more feasible option in terms of preserving biodiversity and their role in the global carbon cycle.