Picus

The Ecosystem Model PICUS

PICUS is a hybrid forest gap model (Seidl et al. 2005) combining a 3D gap model approach (Lexer and Hönninger 2001) with a physiologically-based production approach (Landsberg and Waring 1997). The model simulates individual tree dynamics on 10×10m patches and was applied in this study on a generic one hectare basis. It accounts for spatially explicit interactions between patches via a 3D light module, simulates explicit seed dispersal as well as ecosystem carbon, nitrogen and water cycles. The model features includes a submodel of bark beetle disturbances in Norway spruce and a management module allowing any silvicultural treatment to be mimicked realistically. PICUS has been successfully evaluated in simulating equilibrium species composition as well as in reproducing longterm stand development in growth and yield experimental plots (Seidl et al. 2005). The model has recently been successfully applied to support climate change adaptation planning (e.g., Seidl et al. 2010).