The IUSS Working Group on soil and landscape modelling was established in November 2013. This WG aims to promote and improve quantitative soil and landscape evolution modeling.
Research on the development of soils in their landscape context is not new and attempts to model soilscape genesis can be traced back to Kirkby (1977). At that time, knowledge to quantify soil processes like clay translocation, bioturbation and organic matter complexing was still limited. As a consequence most research focused on modeling landscape development (e.g. Minasny & McBratney, 1999; Schoorl et al., 2002).
Until recently, in most of the landscape models soil evolution was limited to soil production by weathering processes (Minasny & McBratney, 2001) and soil redistribution by geomorphic processes. Only recently other processes like clay translocation were added using empirical techniques (e.g., Vanwalleghem et al.,2013). Though surface soil redistribution processes in current models may be driven by water flow, subsurface migration/accumulation and weathering processes are usually not. This can be considered a drawback to their prospective use, e.g. in the context of global change studies. The (pedometric) soil science community has shown activity in the development of these landscape models, but major actors are geomorphologists, hydrologists and geologists.
Modeling of water-flow driven soil change has a long history, but was for a long time topical: many solute transport models were constructed to evaluate leaching hazards of biocides, acidification, eutrophication, etc. Since a few years, integrated mechanistic models are in development that describe several aspects of soil genesis (bioturbation, C-sequestration, clay migration, decalcification, etc.) at multimillennium temporal extents (Finke & Hutson, 2008). Due to computational constraints, such models are currently limited to the pedon scale, although by distributed modeling spatial some soilscape genesis studies have been done (Finke et al., 2013; Zwertvaegher et al., 2013). Major actors are pedometricians, paleopedologists and geologists.
At this time there is a gap between the 2 approaches: the landscape modelers need more detailed and mechanistic process descriptions while the pedon-scale modelers need the incorporation of matter fluxes (3-D) at the landscape scale in their models. We perceive that the cooperation of scientists active in landscape- and pedon scale modeling in combination with palaeopedologists and process-quantifying pedologists will be needed to bridge this gap.
Different good motives exist to establish a platform where the soilscape- and pedon-modelers can meet and cooperate:
- To tackle current hot questions like “does an eroding landscape act as a C-sink”. This question requires process-based modeling of the C-cycle in combination with spatial soil redistribution modeling, incorporating feedback mechanisms between e.g. C-content and erodibility. To answer landscape reconstruction questions (e.g. geoacheological) and perform landscape evolution studies in the face of global change.
- To supplement and improve global soil data. Despite efforts like GlobalSoilMap, large areas of the world are still poorly covered in terms of knowledge on soils. Mechanistic models will help to improve our current knowledge and allow us to make extrapolation for future scenarios, for example in the light of global climate change.
- To harmonize efforts and identify knowledge gaps in cooperation with scientists measuring soil properties in the field: data to drive integrated soil-landscape models is becoming increasingly available, from for example coordinates measuring efforts such as the Critical Zone Observatory network (http://criticalzone.org/national/).
Chair: Peter Finke, University of Gent, Belgium
Vice-chair: Tom Vanwalleghem, University of Cordoba, Spain
For further information, please contact the WG chairs or see “Contact”