According to land use types within the folderesi̇ basin, determination and mapping of carbon and nitrogen stocks with different fractions

In this study, it is aimed to determine and map the carbon and nitrogen stocks for the different fractions of soils based on the land use types in the Folderesi basin. For this purpose, undisturbed bulk and disturbed soil samples were taken from 123 points and two soil depth levels, through systematic sampling from the Folderesi basin located within the borders of Vakfıkebir and Tonya Districts of Trabzon Province. For the 0-15 cm soil depth levels, organic carbon stocks of soils were 69.06 t/ha, 65.76 t/ha, 76.90 t/ha and 33.92 t/ha on average in the pure forest, mixed forest, pasture, and agricultural areas respectively. Besides, for the 15-30 cm soil depth levels, organic carbon stocks of soils were found to be 41.87 t/ha, 38.24 t/ha, 51.18 t/ha and 17.25 t/ha on average, again respectively for the same land uses. Similarly, for the 0-15 cm soil depth levels, the average total nitrogen stocks were 3.21 t/ha, 2.89 t/ha, 3.69 t/ha and 1.96 t/ha on average, respectively for the same land uses. Moreover, for the 15-30 cm soil depth levels, the total nitrogen stocks were found to be 1.73 t/ha, 1.49 t/ha, 1.95 t/ha and 0.98 t/ha on average, again respectively for the same land uses. Labile carbon, microbial carbon and nitrogen stock amounts were found to be the highest in pasture areas and the lowest in agricultural areas for both depth levels. As the land use types are compared dependent upon the altitude groups, it can be said that the changing climatic characteristics (low temperature) with increasing altitude for both depth levels slow down the decomposition of organic matter, and therefore cause an increase in the stocks of carbon and nitrogen fractions of soils. Due to the variation in soil, climate, vegetation, and site characteristics throughout the basin, it has been significant to conduct such researches in order to develop sustainable soil management strategies and understand carbon and nitrogen stocks in soils.