Empirical forest models

Empirical forest growth and yield models were developed aiming to predict growth and yield using statistical techniques and calibrated for comprehensive data-sets. Empirical forest growth models can be used directly for decision-makings at stand level. They are adequate for describing growth for a range of silvicultural practices and site conditions. Their relatively simple data input requirements and accuracy in predicting growth have made them the principal yield models of forest management. Growth and yield models exist for practically all of the most important forest types in Europe. Some models predict wood quality properties and most have been extensively validated. However, this approach ignores potential changes in environment, genetics, site and silviculture that might occur from rotation to rotation (Bailey and Martin 1996) since there is no link to underlying causes of productivity. Moreover, productivity is based on dominant height (Site Index) rather than the capacity of the site to fix carbon and produce biomass (NPP; Mg/ha/yr).