Determination of spatial distribution of topsoil organic carbon stock using geostatistical technique in a karst ecosystem

摘要

This study aimed to determine the spatial distribution of total soil organic carbon (TSOC) content in surface soils in the karst ecosystem located in the Mediterranean region of Turkey. Land use types and depression areas were determined using Landsat8 and Shuttle Radar Topography Mission (SRTM) data, respectively. Topsoil samples (0-10 cm) were collected in 108 sites and analysed for soil pH, SOC, bulk density (BD), total nitrogen content (N) and particle size distribution. The exponential model was the best model to describe SOC contents, stable model for BD and circular model for TSOC. The SOC content in different land uses ranked as forest (4.10%) > rangeland (2.60%) > cropland (1.41%) areas. Mean TSOC content was identified as 27.22 MgCha(-1) in non-depressed areas and 48.71 MgCha(-1) in depressed areas. TSOC dramatically changed from none-depressed areas to depressed areas were identified in cropland (Delta TSOCcropland = 68.05%). Forest areas were more stable in view of the change of carbon sequestration compared to the other areas (Delta TSOCforest3 = 28.24%). Depression areas play very important role in terms of carbon storage capacity in the Karst ecosystem.