This accumulation is confirmed by both the increased concentration of total organic carbon (TOC) compared with mature soil samples and the extended C/N ratio in this horizon, which might be result of dissolved low molecular compounds of illuviation.
The TOC content in the Shatura plots showed greater concentrations in the mature soil samples (S12) than in the topsoil horizons, which were affected by fire (i.e., S10, S11, and S13).
Data from the Nadym plots (Table 2) showed higher weekly mineralization rates in the topsoil of mature soil than in postfire soil.
If we compare the amount of C[O.sub.2] evolved from topsoil samples of postfire Nadym plots with those from mature Nadym soil samples, we can see that mature soil provides more intensive mineralization than postfire soil, but that this emission remains steady over the time.
In general, weekly amount of evolving was higher in mature soil samples if the data were expressed in g/kg of fine earth (p < 0.05, p < 0.04 and p < 0.04 for pare comparison of topsoils of mature soil with Shatura 10, Shatura 11, and Shatura 13 soils correspondingly).
The weekly evolved amounts, expressed in g/kg of fine earth, were higher in mature soil samples than in fire-affected ones.
These types of tree stands were selected for sampling of postfire soils and mature soils. Because of changes in the hydrological regime, the number of peat fires and areas impacted by peat fires increased dramatically .
This was common for the lowest horizons of T-unaffected soils and the topsoils of mature soils. Fire-affected horizons (i.e., Cpir and Tpir) showed gradually decreasing mineralization rates within the experiment period.