## 4 Discussion  
An analysis of the methods of peatland restoration shows that biochemical trade-offs do not often need to be sufficiently considered. This is mainly due to the lack of long-term ecosystem-level monitoring of CH\({}_{4}\) in northern peatlands. Plant species composition, depth of water table, or soil pH are not sufficiently taken into account [40; 125]. To reduce GHG emissions from peatlands, attention must be paid to agricultural lands where drainage has occurred. These degraded peatland restoration strategies are related to the improvement of landowner and farmer knowledge about the effects of drainage, peatland rewetting afforestation of peatlands, and the impacts on peatland hydrology and climate change [63; 71; 117]. Increased concentrations of DOC in water bodies are often associated with peatland drainage and degraded peatlands. Naturally formed northern peatlands are estimated to be a significant source of GHG emissions due to their constant wet conditions [40; 164]. In a study [29], it was estimated that in the first four years after rewetting, CH\({}_{4}\) emissions increased by ~0.033 \(\pm\) 0.003 Mg CH\({}_{4}\)/ha\({}^{-1}\) yearly [29]. To evaluate the effect of rewetting, a prolonged period should be considered. Often, there are arguments that increased CH\({}_{4}\) emissions after rewetting will decrease after a brief period. In the case of a lack of water table control after rewetting, GHG emissions could remain high for a long period [5]. Some studies [11] even estimated that more than 30 years after rewetting, the average yearly emissions of CH\({}_{4}\) are approximately twice as high as before the extraction of peatland [11]. The effect on nutrient flow and GHG emissions using brackish water for rewetting is still uncertain compared to freshwater [39]. Regarding coastal peatlands, a study [39] estimated that using brackish water for rewetting can have smaller CH\({}_{4}\) emissions compared to rewetting where freshwater is used [39]. Peatland rewetting impacts nutrient mobilisation and eutrophication in nearby water bodies and releases an essential amount of CH\({}_{4}\). Similarly, peat saturated with water promotes nitrate attraction [39]. Studies [39] have shown that rewetting previously drained coastal peatlands can be a GHG emission source in the first year. Regarding coastal peatlands, it is estimated that rewetting can result in unmonitored inputs of nutrients in nearby water in the short term [39]. After the peatlands' rewetting, the peat bulk's density could remain high. Therefore, because of rewetting, new biotopes like entropolated lakes can form on the degraded soil [12; 52]. According to the literature sources, there is still some uncertainty regarding the DOC concentration level after peatland rewetting [29]. Some studies have shown no effects on DOC concentrations after peatland rewetting, or the effect is vague [29]. For a successful restoration strategy and mobilisation, it is vital to assess CH\({}_{4}\) fluxes. It is estimated that rewetting might reduce net CO\({}_{2}\) emissions in reforested sites by ~15.4 Mg CO\({}_{2}\) equivalent ha\({}^{-1}\) annually, a 25% reduction in the total [29]. Monitoring should be improved to ensure control over the nutrient release in nearby water bodies near peatlands. The monitoring of vegetation and hydrology should be simultaneously evaluated [51]. Monitoring should be conducted before and after peatland restoration [51]. Several methods can be used in peatland monitoring, including spatial analysis, aerial and drone photos, and a combination of vegetation, hydrology, and GHG emission measurements [50]. Brackish water use for peatland rewetting can reduce GHG emissions. It is also estimated that the reduction of CH\({}_{4}\) emissions after rewetting can be achieved by using fresh water for rewetting [29]. Reducing CH\({}_{4}\) emissions from rewetting and restoring the balance of the carbon topsoil removal can be used to avoid additional nutrient release.