Wanda is a process based regional nitrogen model. It calculates nitrate leaching as a function of deposition, landuse and management. The focus in WANDA is on forests. Here, nitrate leaching is regulated by deposition, tree species, tree age and the C/N ratio in the forest floor. In Figure 1 an overview of the nitrogen fluxes in WANDA is given. The numbers in the diagram indicate the order in which de demand of inorganic nitrogen by plants and microbes is compared with the availability of inorganic nitrogen. The central concept in WANDA is the relationship between C/N ratio in the forest floor and nitrate leaching. This relationship has been observed in several correlative studies of nitrogen cycling in European and North American forests. In addition to nitrogen, WANDA calculates water fluxes in the ecosystems. The time step in WANDA is one year. The model is written in Pascal.
