## 3 Results and Discussion  
### Physicochemical Characteristics of the Peat Profile  
The values of active acidity in the studied peat profile vary from 3.66 to 4.47, while the exchangeable acidity is in a more acidic pH range, 2.67-2.97. According to the data obtained, the studied peat can be attributed to the strongly acidic group, since the pH values are below 4.5. The acidity of peat is due to the presence of free acids, in particular acetic, formic, oxalic, lactic, and other acids [47]. In the vertical distribution of active and exchangeable acidity, a slight decrease with depth is observed. The content of carbonates in the peat of the studied section is insignificant and is in the range of 0.06-0.30%. The graph of the vertical distribution of carbonate concentration shows a non-monotonic increase in CO\({}_{3}\)\({}^{2-}\) up to a depth of 25 cm, followed by a gradual decrease. The value of the ash content index for the studied peat profile is in the range of 1.10-5.77%. The obtained values make it possible to classify the peat deposit as a low-ash type, since the ash content, in general, does not exceed 6%. In the vertical distribution in the 19-21 cm horizon, there is a maximum content of ash components, which is probably due to the leaching of ash components from the surface layers of peat and their concentration in this layer. Anthropogenic impact, manifested in the past, can also be the reason for the jump in the ash content. Below a depth of 19-21 cm, there is a tendency for a nonmonotonic decrease in concentrations when moving to deeper layers of the profiles, which is associated with the atmospheric type of feeding of the bog. According to several studies, peat ash consists of 98-99% oxides of silicon, aluminium, iron, calcium, magnesium, sodium, phosphorus, and sulphur [47]. The reverse indicator of ash content, the proportion of organic matter, increases from a depth of 19-21 cm and is at a level of more than 90%, which indicates a low degree of decomposition of high-moor peat [57]. The content of water-soluble salts is in the range of 0.84-1.78 mg/g. The maximum concentration of salts is observed in the uppermost layer of peat. Below the section, there are several peaks in the content of water-soluble salts at depths of 15-17 cm and 23-25 cm. The results obtained make it possible to attribute the studied peat to the acidic facies of oligotrophic peat soils [58]. According to the obtained experimental results, the studied part of the profile of the peat deposit is composed mainly of sphagnum peat. The structurally sensitive parameters of peat--the degree of decomposition (R) and bulk density (Table 1) gradually increase with depth and are in the ranges of 0-7% and 0.075-0.109 g/cm\({}^{3}\) undisturbed state [59; 60]. The natural moisture content is in the range of 15-24 g/g and decreases with depth, which is partly due to the gradual compaction of the porous structure of peat when moving from the surface, deep into the deposit. The dynamics of changes in the Eh\({}_{4}\) and rH values (Table 1) along the depth of the studied part of the peat profile (acrotelm and upper part of the cathodelm) indicate the presence of a contrasting redox regime, in which moderately oxidising conditions are gradually replaced by an intense reduction in oxidising conditions. This is due to the peculiarities of the aeration of the deposit and the level of swamp water fluctuations, which during the sampling period (spring-autumn period 2021) was in the range of \(-\)25-0 cm. See more Appendix A, Table A1. The relative content of the main elements in the organic matter of peat was 0.9-1.6 (N); 27.3-34.4 (C); 46.3-53.9 (H); 16.8-19.3 (O) atomic %, which is generally typical for the biomass of bog vegetation and peat with a low degree of decomposition (Figure 2). The H/C value is in the range 1.3-2.0, which indicates a clear predominance of aliphatic structures in the organic part of peat (H/C \(>\) 1) [61].