Spatial distribution and controls on organic and inorganic carbon in the soils of Cyprus

This study examines the spatial distribution of soil inorganic carbon (SIC) and soil organic carbon (SOC) in samples from over 3200 sites across Cyprus, collected as part of the Geochemical Atlas of Cyprus project. The concentration of SIC is largely controlled by underlying lithology, with distinct variations between the main geological terranes, especially across the boundaries between the mafic-ultramafic units of the Troodos Ophiolite and surrounding carbonate-dominated sedimentary units. Geology, land use, major and trace element concentrations, climatic factors and SIC have little influence on SOC, whereas vegetation type does have an influence as reflected in slightly elevated values in the forested Troodos Mountains and coastal wetlands compared with other areas. SOC displays more restricted spatial correlation than most other soil geochemical variables, indicating complex controls by specific site characteristics and other factors. The mean SIC and SOC values of 2.15% and 1.52% respectively are broadly consistent with previous localised studies of soils in Cyprus but less than that predicted using the low-density sampling of the GEMAS project. The average values are similar to other regions in southern Europe with comparable climatic, geological and soil characteristics. The results yield an estimated 27 Mt of SOC contained in the top 20 cm of soils in Cyprus including 6 Mt in forested areas. The extensive database and network of sampling locations provides an important resource for both long-term direct monitoring of changes in SOC in the soils of Cyprus and the development and testing of alternate SOC mapping methods including remote sensing.