Studying altitude influence on some soil properties, soil organic carbon total nitrogen content and stock capacity of black pine on north aspect

Main aim of this present study was to investigate the effects of slope position on soil properties, soil organic carbon and total nitrogen content and stock capacities of Black pine (Pinus nigra) in Daday, Kastamonu. For this aim, soil samples of Black pine (Pinus nigra) were collected from two altitudes (871 m and 1189 m) on the north aspect. The soil samples were taken randomly from 0-5cm, 5-10 cm, 10-15 cm, 15-20 cm, 20-25 cm and 20-30 cm soil depths and analyzed for soil pH, soil texture, bulk density, soil macro and micro nutrient concentrations, soil organic carbon (SOC) and total nitrogen (TN) content. The SOC and TN stock capacity were then calculated by multiplying soil volume, soil bulk density, and the SOC or TN content. Among soil properties, only sand and clay content showed significant diffreneces between altitudes (P<0.001). Soil carbon content only showed significant differences between the altitudes. However, soil total nitrogen content had a significant difference either between the altitudes or between the soil depths. Mean soil organic carbon stock capasity was higher (137.1 Mg C ha-1) at the higher altitude than that at lower altitude (87.7 Mg C ha-1). Mean total nitrogen stock capasity was also higher at the higher altitude (7.72 Mg N ha-1) than that at the lower altitude (4.51 Mg N ha-1). Both SOC and TN stock capacities did not show clear differences between the soil depths. Soil macro nutrients (P, K, Ca and Mg) showed significant differences between the altitudes (P<0.05). Mean soil macro nutrients; Mg, P and K concentrations were significantly higher at the higher altitude than those at the lower altitude, whereas mean soil Ca concentration was lower at the higher altitude than those at the lower altitude. Soil micro nutrients, Mn, Na, Zn, Cl, Al and Co concentrations were also significantly higher at the higher altitude than those at the lower altitude. In conclusion, our results indicate that topographical factors, slope aspect in this present study, can significantly affect soil properties and soil organic carbon and total nitrogen content. Therefore, those factors should be considered in the future studies. Keywords: Soil properties, soil organic carbon, total nitrogen, altitude, Kastamonu