Effects of deforestation on soil properties and organic carbon stock of a hillslope position land in Black Sea Region of Turkey

Abstract

The effects of deforestation on soil properties and soil organic C (SOC) stock in adjacent pasture and forest areas located on the same hillslope position were investigated. The soil properties measured in the forest site had higher coefficient of variation compared with pasture site. Deforestation made almost 50 years ago significantly increased bulk density (Db), soil pH, exch. Mg and significantly decreased total porosity (F), gravimetric moisture content (W), EC, exch. K, soil organic matter (OM), SOC stock in 0-15 cm soil depth in pasture site. Mean Db increased fom 1.24 g/cm3 in forest to 1.42 g/cm3 in pasture while mean values of OM and SOC stock depleted from 4.41% and 30.70 ton/ha in forest to 1.89% and 15.55 ton/ha in pasture, respectively. The reduction ratios in some soil properties by changing land use type from forest to pasture were determined in the following order; OM (57.14%) > exch. K (55.88%) > SOC (49.35%) > EC (45.65%) > W (28.96%) > exch. Na (18.75%) > F (11.32%) > exch. Ca (4.07%). The values of OM and SOC stock had significant positive relations with F, W, EC, exch. K, and significant negative relations with Db, pH, exch. Mg. After deforestation, abandoning cultivated land to pasture had negative impact on the soil properties and depleted SOC stock in 0-15 cm soil layer.

Keywords

• land use
• pasture
• deforestation
• soil organic c
• soil properties