System–Ecological Analysis of Seasonal Catalase Activity in Peat Soils of Drained Pine Bogs in Western Siberia

Peat soils (Drainic Hemic Histosols) of reclaimed mesotrophic (transitional) bogs in the southern taiga subzone of Western Siberia, occupied by naturally regenerated pine stands (Pinus sylvestris L.), were studied. The most favorable conditions for the development of soil catalase activity were observed under moderate drainage. At this drainage level, catalase activity in slightly and intensively drained soils amounted to 71% of that in moderately drained soils and did not differ significantly from each other. A statistically significant parabolic relationship has been established between seasonal catalase activity and time. Parabolic trends for slightly and intensively drained soils show that catalase activity increased by an average of 1.04 and 1.27 absolute units per week, respectively, with a mean weekly deceleration of 0.12 and 0.14 units. In moderately drained soils, catalase activity decreased by an average of 1.31 units per week, accompanied by a mean weekly acceleration of 0.076 units. Analysis of time-series indicators has made it possible to identify intraseasonal periods of catalase activity, determine the direction and intensity of changes, and differentiate the soil profile (0–5, 5–10, and 10–30 cm) according to process intensity. The 5–10 cm layer, equivalent to the concept of a median (with growth coefficients increasing upward along the profile and decreasing downward by approximately 1.5–2 times), most closely corresponded to the seasonal enzymatic activity of the entire soil profile (0–30 cm) throughout the season. A highly significant, predominantly parabolic, positive regression relationship has been established between soil catalase activity and volumetric moisture (in the range of 17–71%), pH value of 3.6–4.4, and redox potential of more than 600 mV, whereas a negative relationship was observed with temperature in the range of 2–17°C. According to canonical analysis, the combined effect of the studied parameters amounted to 82% in slightly drained soils, 40% in moderately drained soils, and 57% in intensively drained soils. Factor structure coefficients identified volumetric moisture as the dominant environmental parameter regulating enzymatic activity in peat soils.