Abstract
A bio-economic model provides a framework for simultaneously considering breeding, management, and production decisions. Such a model should result in optimal breeding (and silvicultural) objectives if main goals of a production system are well defined. Historically estimation of economic weights for breeding-objective traits has been based on partial regressions and profit functions relating only to certain parts of the production system. A bio-economic model includes effects of growth rate, branching, form, and wood quality on all production system components and on overall profitability of an integrated production system. However, long rotation cycles in forestry make determination of relative economic values for the breeding-objective traits particularly difficult. When modelling complex systems under uncertainty about future production goals, there are necessary trade offs between the complexity of the model and the use of simplifying assumptions.