Relationships between the content of C, N, P and their stoichiometry in the soils of selected forest reserves of the Białowieża Primeval Forest.

The aim of the study was to assess the correlation between the content of C, N, P and the C:N and C:P ratios in the soils of the Białowieża Primeval Forest reserves in north-eastern Poland. The research was carried out in forest reserves in the Lipiny, Dębowy Grąd, Władysława Szafera and Koryciny reserves in the Białowieża Primeval Forest (north-eastern Poland). Soil samples were collected in the fall of 2021 from the layers: 0 (litter), 0-5, 5-10, 10-20, 20-40 cm, and after drying and preparation, the pH was measured in 0.01 mol CaCl₂·dm^-3 and the content of N_Tot and P_Tot. Soils were acidic (pH_CaCl2: 4.32-5.00) and the average nutrient contents were in the range: for C (68.4 - 110.0 g·kg^-1 in DM); N (2.95-3.45 g·kg^-1 in DM); P (0.187-0.516 g·kg^-1 in DM). Significant positive linear Pearson correlations (p = 0.00001) were obtained for C_Tot x N_Tot (R = 0.916); C_Tot x P_Tot (R = 0.666); N_Tot x P_Tot (R = 0.665) for all objects. The stoichiometric ratios had a wide range for C: N (10.71-52.70) and C: P (4.78-1445.0). Their highest values ​​were recorded in the litter ("0") and in the layer 0-5 cm deep. A significant value of C:N>20 and C:P>300 may indicate the accumulation of soil organic matter "carbon sequestration" and an increase in biological phosphorus sorption.