Effects of aspect on carbon and nitrogen storage capacity of oak, scots pine and black pine

Changes in the carbon stocks and total nitrogen of biomass, organic layers strongly influence soil properties and litter quality, so unsuitable practices lead to degradation of soil and environmental quality. The main aim of this present study was to investigate the effects of an aspect of soil organic carbon and total nitrogen content and stock capacities of Oak, Scots pine, and Black pine in Daday, Kastamonu. For this aim, soil samples of Black pine and Scots pine were collected from the altitudes of 871 m on the north- and south aspect. And soil samples of Black pine and Oak were collected from the altitudes of 1100-1200 m on the north- and south 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 micronutrient concentrations, soil organic carbon (SOC) and total nitrogen (TN) content. The SOC and TN stock capacity were then calculated by multiplying the soil volume, soil bulk density, and the SOC or TN content. Soil properties showed significant variations with aspects and soil depths, but these differences varied with tree species. Soil C and N content and stock capacities of Oak and Black pine stands collected from north and south aspects at the altitude of 871 m and 1100-1200 m showed significant variations with the aspects. For example, for oak, mean soil carbon content on the north aspect was higher than on the south aspect, whereas total nitrogen content was lower on the north aspect than on the south aspect. As for the SOC and TN stock capacities for oak, mean soil organic carbon stock capacity was higher (15,4 Mg C ha-1) on the north aspect than that of on the south aspect (69.0 Mg C ha-1). Mean total nitrogen stock capacity was also higher on the north aspect (5.03 Mg N ha-1) than that of on the south aspect (4.44 Mg N ha-1). In conclusion, our results indicate that topographical factors, an aspect of this present study, can significantly affect soil properties and soil organic carbon and total nitrogen content and stock capacities. Therefore, these factors should be considered in the future studies.