Klum: A Simple Model Of Global Agricultural Land Use As A Coupling Tool Of Economy And Vegetation

The Kleines Land Use Model (KLUM), is a global agricultural landallocation model, developed as a tool to dynamically couple global state-of-the-art vegetation and economy models. The allocation process is based on profit maximisation, assuming risk aversion and decreasing returns to scales. The model is suited for long-term predictions, acknowledges spatial and biophysical diversity and enables the data exchange with common vegetation models. Finally, the effective simplicity of the mechanism facilitates online-coupling with larger models. Simulations of future crop allocation under climate change suggest that cultivation of cereals would fall in favour of minor crops such as vegetables and fruits. Total revenue of crop production is predicted to increase for most parts of the world. The comparison with two reference scenarios, where solely prices or yields are changed show that the observed results are dominated by the induced price changes. Losses in revenue prevail and changes in area are more balanced over the world when only the much smaller yield changes are applied. Yet, the simple sum of price and yield effects on crop allocation can differ in magnitude and sign from the real dynamics, emphasising the importance of simultaneous inclusion of economic and biophysical aspects of land-use decisions.