Models for Mixed Forests

Abstract

The basic classification of models based upon the modelling concept distinguishes empirical, process-based and structural models. Universal multidimensional classification distinguishes ten model categories practically very important. Character of input data for forest models depends mainly on the concept of the model and its category. Different tools for input data can be utilised. Extensive set of components, which deal with different parts of forest development, is also available. They are, e.g. partial models addressing mortality, competition, growth, nutrient cycle, thinning interventions, felling approaches or regeneration establish- ment. The output data also depends primarily on the concept of the model and its category. Generally four essential principles can be applied for modelling of mixed stands as follows: (I) weighted mean of pure stand characteristics, (II) considering mixing effects by multipliers, (III) spatially explicit competition model, (IV) ecophysiological process approach. Different levels of model applicability for simulating mixed forest stands exist. Suitability level for mixed stands increases from the top downwards, and it is joined with model categories and essential principles used. M.