## 1 Introduction  
Peat plays a vital role in peatland ecosystems for vegetation growth and habitats, ensuring biological diversity [1, 2, 3]. Peatlands are critical in climate regulation as carbon sinks [1, 4, 5, 6, 7, 8, 9]. Peatlands are the most significant natural terrestrial carbon sink, which can continuously attract carbon from the atmosphere over long periods [8, 10, 11]. While peatlands cover only 3% [12, 13, 14] of the area, they store 30% of the world's carbon [8, 9]. The resource's quality has decreased [15, 16, 17, 18], and peat is currently viewed more as an emission source [5, 15, 19, 20]. Peatlands have to be managed sustainably, interrupting extensive peatland drainage and extraction [21]. It is estimated that more than half of the peatlands in Europe are lost [22]. The increase in population density and intensity of agricultural practices has driven the increased drainage of large European peatlands [23]. In Europe, 25% of peatlands are estimated to be degraded [23]. In Europe, peatlands can be found in wide areas in Eastern Europe, Central Europe, and Northern Europe. These regions include Ireland, the United Kingdom, Germany,Austria, The Netherlands, Poland, the Nordic countries, and all the Baltic states [24; 25; 26]. In Finland, more than 30% of the territory is covered with peatlands [12; 17], but in Sweden, it is approximately 15% of the territory's land surface [4]. In Iceland, peatlands cover ~9% of the total area [27], while in Norway, peatlands cover ~6% of the land territory [12]. About 12% of the peatland area has been drained and used for forestry and agriculture [28]. The water table is low at the drained peatland level; therefore, carbon dioxide (CO\({}_{2}\)) emissions increase. In peatlands where drainage has been carried out, CO\({}_{2}\) is the main GHG emission [29]. It has been determined that drained peatland causes ~2% to 5% of the emissions of greenhouse gas (GHG) emissions and ~10% of CO\({}_{2}\) emissions in total [30]. Degraded peatlands produce large GHG emissions and greatly affect peatlands' water-holding resistance [31]. Peat continues to be one of the main energy sources in Europe, for example, in Sweden and Finland [32]. The extensive drainage of peatlands for agricultural use, extraction as an energy source, and removal of all but a thin peat layer explain the decrease in peat quality [20; 33]. It is predicted that in northern peatlands, GHG emissions from peatlands might increase in the following years because of global warming [34]. The European Union (EU) is rated as the third greatest carbon dioxide (CO\({}_{2}\)) emitter of degraded peatlands after Russia and Indonesia [31], with annual GHG emissions of roughly 220 million megatons of CO\({}_{2}\) equivalents/year [35; 36]. Some of the greatest CO\({}_{2}\) emissions in the EU from degraded peatlands are in Poland, Germany, and Finland [31]. The degraded peatlands used for agriculture are significant emission sources, emitting CO\({}_{2}\) and CH\({}_{4}\) into the atmosphere [37; 38; 39]. In their natural conditions, peatlands are also CH\({}_{4}\) emitters [40]. At the same time, natural peat bogs sequester CO\({}_{2}\) from the atmosphere and, thus, compensate for the emission of CH\({}_{4}\). The effect of N\({}_{2}\)O on global warming is higher than that of CO\({}_{2}\) by an approximate factor of 265 [41; 42; 43]. Nitro oxide (N\({}_{2}\)O-N) emissions increase along with the increase in peat soil degradation. In the form of N\({}_{2}\)O-N, EU peatlands release around 145 gigagrams of nitrogen per year [44; 45]. The amounts of GHG emissions from peat are affected by the type of peat, the carbon-to-nitrogen ratio in the soil, hydrology, temperature, land use, and biodiversity [1; 2; 7; 46]. In 2015, climate targets were set at the Paris Climate Conference (COP 21)--to reduce the GHG emissions in the EU by 40% by 2030 compared to 1990. The EU signed a binding agreement with states to act towards achieving these targets. To achieve these targets, the GHG emissions from peatlands must also be minimised [47].