A semi-distance-dependent individual tree growth model for coppice forests in Austria

Management of coppice forests is becoming more important currently. Therefore a growth simulator was developed for planning. The two core models are presented in this paper. Height growth models for 11 different species an one species-group (other broadleaf species) were developed as well as 5-year basal area increment models for four species and one species-group occurring in Austrian coppice forests. The data were measured on 54 sample plots covering diverse sites, stand ages and treatments. 3,260 trees belonging to 24 different species were used to fit the models. A new coppice-specific competition measure "basal area of larger trees within the stool" BALi was introduced, therefore the model is called "semi-distance-dependent". Depending on the biological plausibility either nonlinear or robust linear models (tree height) or robistified linear mixed models (basal area increment) were fitted.