Hydrological and vegetation change during peatland restoration at ex-forested sites in a blanket bog ecosystem

Abstract There is a global shortage of long-term, controlled experiments assessing the effectiveness of land-use interventions, especially in peatland ecosystems. These habitats play a crucial role in biodiversity conservation and climate regulation, yet forest-to-bog restoration remains poorly understood and under-evaluated at scale. We aimed to test the effectiveness of different restoration techniques in converting non-native conifer plantations back to functioning bog ecosystems, using a rigorous, replicated, long-term experimental framework to generate robust evidence to support peatland conservation and climate policy. At a 21,500?ha nature reserve in the Flow Country UNESCO World Heritage Site (northern Scotland), we established two large-scale replicated experiments (2?8?ha blocks) using a Before-After-Control-Impact (BACI) design. Treatments compared ?standard? and ?enhanced? approaches to hydrological restoration and tree removal, alongside intact bog and forestry controls. Hydrological and vegetation responses were monitored over a 6?7-year period following intervention. Enhanced restoration techniques led to more rapid recovery of bog-like conditions, including raised and stabilised water tables and the re-establishment of characteristic vegetation assemblages. These outperformed standard restoration methods and demonstrated significant ecological gains within a relatively short timeframe for forest-to-bog conversion. Despite the long timescales typically required for peatland restoration, our results show that enhanced methods can significantly accelerate early recovery. These findings demonstrate the importance of experimental rigour in restoration science and provide critical insights into effective peatland management. Synthesis and applications. Our study highlights the value of large-scale, replicated experiments with robust BACI designs in evaluating restoration success. Enhanced restoration methods show clear ecological benefits and should be prioritised in policy and practice to improve the effectiveness and efficiency of peatland restoration for biodiversity and climate objectives.