Soil organic carbon stock prediction using multi-spatial resolutions of environmental variables: How well does the prediction match local references?

•Soil organic carbon (SOC) stocks predicted using machine learning algorithms.•Spatial resolutions of environmental variables examined on national and global data.•Source of data (national or global) defines the importance of environmental variables.•Independent reference data showed a significant decrease in prediction accuracy.•DSM should be re-evaluated by local data when spatial data differ from the original data.