A significant part of the restoration of mires and forests, as well as related research, has been carried out in southern Finland, where protected areas are small and fragmented, and their natural state has been degraded. In northern Finland, protected areas are large in area, and even areas affected by forestry are located adjacent to or in close proximity to natural areas. For this reason, the goals, practices, and research questions related to restoration in northern Finnish protected areas may at times differ significantly from those in southern Finland. In the GreenBelt LIFE project (LIFE04 NAT/FI/000078), which began in 2004 in Koillismaa and Kainuu, a total of 600 hectares of forest and 362 hectares of mires were restored between 2005 and 2007. The comparison of the success of these measures and the study of their ecological impacts forms the first comprehensive restoration research project in northern Finland and one of the most extensive restoration studies in the entire country. ####Methods The study compares the effects of different restoration measures on mires in Kainuu and Northern Ostrobothnia. Restoration methods include timber harvesting or whole-tree harvesting, as well as ditch blocking. The research focuses on hydrology, vegetation and tree structure, litter decomposition, and peat mineralization. Restoration experiments were established in three Natura 2000 areas managed by Metsähallitus at the beginning of the GreenBelt LIFE project . The Natura 2000 areas locate in Kuhmo (Elimyssalo, Iso-Palonen-Maariansärkät, Teerisuo-Lososuo). These areas represent typical aapa mires that were drained in the 1970s and 1980s. Additional research sites are located outside the project area around the Bothnian Bay (Tauvo in Siikajoki). In the planning phase of the study in 2005, a total of 12 mire areas were selected—10 in Kuhmo and two in the Bothnian Bay region, Siikajoki. In Kuhmo, timber harvesting was carried out on 7 mires and whole-tree harvesting on 3 mires, with a nearby natural mire serving as a reference. In Siikajoki, both mire areas underwent timber harvesting, with a natural mire and an unrestored drained mire serving as references. Baseline measurements before restoration were conducted between 2005 and 2007. Post-restoration monitoring began immediately after the measures. In Kuhmo, restoration was carried out by removing the tree stand according to the experimental design during the winter of 2006–2007 and blocking the ditches in August 2007, after which monitoring of the restoration began. In Siikajoki, the measures were implemented one year later. ####Survey In Kuhmo, a total of 546 table water wells were installed in the mires to measure water level. Water acidity and temperature were measured in some of the wells during the first study years. Measurements were taken once a month from May to October during 2005–2006 and before restoration in July–August 2007. After restoration, measurements were conducted monthly from May to October during 2006–2009 and in May, August, and October during 2010–2013. In a similar way, 114 table water wells were installed in Siikajoki, and they were monitored during 2006–2014. Additionally, separate sampling wells were established on two natural mires (4 each) and on two restored mires for both harvest treatment (3 next to a ditch and 3 in the middle of the mire). From these wells, water samples were collected in May, August, and October during 2008–2013 to monitor nutrient leaching. Vegetation succession, tree structure, litter decomposition, and peat mineralization were monitored around table water wells or from squares established next to the wells. Some of the wells were selected for monitoring in the middle of the strip and next to the ditch, as well as in a natural mire. These variables were monitored periodically. More detailed information describing the variables and measurements can be found in separate files. In addition, there is a model image of the layout of the monitoring sites in its own file. The open data includes the model of monitoring layout, experimental plot information, measurement times, and variable descriptions as well as their relations. Data will be open after it has been published.

2025