Studying tree species influence on some soil properties, soil organic carbon and total nitrogen content and stock capacity under similar site conditions

This study was carried out in Daday, the north-west of Kastamonu province in order to assess the difference in soil properties, soil macro and micro nutrients, soil organic carbon and total nitrogen and stock capacities between three tree species and soil depths. Soil samples were collected from 6 soil depths (0-5 cm, 5-10 cm, 10-15 cm, 15-50 cm, 20-25 cm, 25-30 cm) at the altitude of 1189 m for beech, Scots pine and black pine stands, and at the altitude of 871 m for oak and black pine stands. Results showed that at the altitude of 1189 m, soil bulk density, moisture and soil pH were significant (P< 0.01, P< 0.05 and P< 0.05 respectively) between the three tree species. Soil texture (sand, clay and silt) did not vary among the three tree species. At the altitude of 871 m, only soil pH was only significant (P< 0.05) between the two tree species (oak and black pine). Total nitrogen content was statistically significant (P< 0.01) at the altitude of 1189 m, whereas soil organic carbon contents did not vary between the tree species either at the altitude of 1189 m or of 871 m. Total nitrogen content at the altitude of 871 m, did not also significantly vary with the tree species. However, when all soil depth was considered, there were indications that black pine stands at the altitude of 1189 m had higher mean soil organic carbon and total nitrogen content than beech and Scots pine. At the altitude of 871 m, oak and black pine stands showed similar mean soil organic carbon and total nitrogen content. As for the SOC and TN stock capacities at the altitude of 1189 m for beech, Scots pine and black pine, mean soil organic carbon stock capacity was highest for black pine, followed by beech and Scots pine. Mean total nitrogen stock capacity was also highest for black pine, followed by beech and Scots pine. Both SOC and TN stock capacities did not show clear differences between the soil depths. The SOC and TN stock capacities at the altitude of 871 m for oak and black pine, they showed similar results for the SOC stock and the TN stock. At the altitude of 1189 m, black pine stands had the highest mean soil macro nutrients (Ca, Mg, P, K and S), whereas Scots pine stands had the lowest P, K and S. Only Ca content was lowest for the beech stands, and Mg content was similar for beech and Scots pine stands. At the altitude of 871 m, mean soil macro nutrient contents (Mg, P, K and S) were similar between the oak and black pine stands. Only Ca content was higher for the black pine stands than the oak stands. beech stands At the altitude of 1189 m , had the highest mean soil micro nutrients (Fe, Mn, Na, Zn, Cl, and Al), followed by Scots pine and the lowest by Black pine. Contents of Cu and Co were, however similar between the three trees. At the altitude of 871 m, mean soil micro nutrient contents (Fe and Mn) were higher for black pine than for oak stands. However, other mean soil micro nutrients (Na, Cu, Zn, Cl, Al and Co) were similar between the oak and black pine stands.