In this study, the effects of different canopy closures and slopes on aboveground, soil, and belowground biomass (B) and carbon (C) storage in pure black pine (Pinus nigra subsp. pallasiana), mixed black pine - Scots pine (Pinus sylvestris), and black pine-Turkey oak (Quercus cerris) natural stands were investigated. The study was conducted in 88 sample areas selected using a selective sampling method within the boundaries of Atakum (Ada) and the Boğaziçi Forest Management Directorate in Samsun Province. Samples were taken for the aboveground, soil, and belowground components of these areas. The mean tree method was used to estimate tree C storage, while multiple variance analyses were applied to evaluate differences in B and C stocks. According to the obtained findings, average aboveground tree B in pure black pine, mixed black pine - Scots pine, and black pine - Turkey oak stands were 63.61 t/ha, 67.41 t/ha, and 86.51 t/ha, respectively; total vegetative mass was 102.97 t/ha, 101.43 t/ha, and 127.84 t/ha, respectively; aboveground tree C was calculated as 28.93 t/ha, 30.45 t/ha, and 36.49 t/ha, respectively. Similarly, total plant C amounts were 46.07 t/ha, 47.85 t/ha, and 53.08 t/ha; soil organic carbon (SOC) values were 119.42 t/ha, 103.07 t/ha, and 100.88 t/ha. While land slope had no significant effect on B and C storage, B and C storage varied with canopy closure. Additionally, it was found that stand structure, rather than soil properties, was a key determinant of C storage.
Kahveci et al. (Mon,) studied this question.