Simulation models offer the possibility to link properties, processes and functions of the vadose zone or the so-called critical zone. Such a link is essential to develop a knowledge based management of this zone and its important functions. Because of the diversity of soil functions that are in focus, there is a large diversity of vadose zone models that address different questions in different scientific communities. However, since they share the same environmental compartment, there are also ample commonalities. A key point is if common (sub)processes in these model predict the common state variables and fluxes in the same way, and if not, what is the underlying reason. In this session we would like to bring together developers and users of models that simulate different soil functions and we are welcoming contributions that discuss:

• recent model developments with respect to certain soil processes and functions

• differences between models and model approaches

• the development of a multi-disciplinary model platforms that bring together different models and that address a wider range of soil functions

• links of soil models with other environmental compartments and their integration in multi-compartment terrestrial system models.