Effects of Land-Use Change on the Soil Organic Carbon and Selected Soil Properties in the Sultan Marshes, Turkey

Abstract

This study aims to assess the effects of land-use changes on the carbon storage capacity and some soil properties of The Sultan Marshes, a wetland partially drained and converted to other land uses during the middle of the last century. Undisturbed soil sampling was performed in different land-use types (rangelands, shrubs, marsh, agriculture, and dried lake area) in the wetland area at depths of 0-50 cm, and soil organic carbon (SOC), bulk density, and carbon stocks of soils for each land use type were calculated at 10 cm soil depth levels. Furthermore, disturbed soil samples were taken at two soil depths (0-20 cm and 20-40 cm), and the particle size distribution, pH, electrical conductivity (EC), aggregate stability and dispersion ratio (DR) properties of the soils were analyzed. Data were processed using ANOVA, Duncan's test, and Pearson's correlation analysis. The soil properties affected by the land-use change were SOC, carbon stock, pH, EC, aggregate stability, clay, silt, sand contents, and bulk density. SOC and carbon stocks were high in rangeland, marsh, and shrub land, while low in agriculture and drained lake areas. As the soil depth increased, SOC and carbon stock decreased. The organic carbon content of the soils exhibited positive relationships with aggregate stability, clay, and carbon stock, while it showed a negative correlation with bulk density, pH, and DR. The results showed that s drainage and conversion of the wetland caused a significant decrease in the carbon contents of the soils.