Peatland restoration in Västerbotten, Sweden : a vegetation composition survey assessing the effects of restoration

Sammanfattning

It is estimated that approximately 1.5 million hectares of peatlands in Sweden have been drained to benefit forestry. Ditching affects the hydrology of peatlands, driving the surface peat to become drier by lowering the water table, which diminishes the provided ecosystem services and natural vegetation composition. Peatlands are crucial ecosystems for nature-based solutions to combat climate change. Boreal and subarctic peatlands cover only a small percentage of the earth´s surface but store almost one-third of the earth’s carbon. Peatlands are also meaningful because they give rise to ecosystem services and a diversity of life forms. Conducting ecological restoration could effectively cease the loss of biodiversity in degraded ecosystems. Restoring degraded peatlands might be one way to tackle both climate change and biodiversity loss. However, certain dynamics of peatland restorations are still unexplored. Further research is needed to improve restoration effectiveness and knowledge of how the vegetation composition is affected by restoration. This study aims to examine the early effects of peatland restoration and its impact on vegetation composition in northern Sweden on mire and swamp forest sites. Floristic inventories were collected across ten sites in Västerbottem, Sweden, from the 5th of June until the 5th of July 2024. Each site was divided into three separate treatments: restored, drained and pristine. The analysis revealed that peatland restoration in northern Sweden, at least in the short term, might increase the presence of typical wetland species and decrease the presence of forest species in mires. This is positive since the recovery of peatland ecosystems is recognised by a decline in species typical to unrestored conditions. Additionally, a difference in species richness between the treatments across swamp forests and mires was observed. Vegetation composition also differed between the majority of treatments across swamp forests and mires, whereas the investigated environmental variables had a small effect on the explained variance. Further research is needed to be done on nutrient availability and restoration success when selecting sites for restoration efforts. With more knowledge, it might be possible to improve the restoration effort and thus increase biodiversity in restored peatlands.