Definition of priority areas for soil protection at a continental scale

Resources for achieving better soil protection are limited and need to be effectively targeted. Spatial variability is high for soil types and related quality and for the risk of degradation because of the threats of organic matter decline, erosion, compaction and salinization. A framework is presented for mapping priority areas for soil protection based on assessing where there is greater risk of degradation and evaluating its acceptability. A conceptual model is proposed which links anthropogenic hazards, threats and the risk of degradation with soil functions. It is recommended that a set of test areas is defined according to dominant soil types, and the probabilities of changes to soil properties relevant to soil functions are then estimated. The risk of exceeding a particular degradation threshold within these test areas can then be assessed and assigned to risk categories to provide the basis for the identification of priority areas.