An illustrative model has been developed to demonstrate how a measurement system could work. The model uses a spreadsheet to project forest growth through time under different management scenarios. The data represents western Washington even aged commercial timberland for all owners in terms of age class by acres. The present distribution is skewed towards younger age classes as the result of past timber production policies. Alternative management scenarios are examined for environmental benefits and costs.
Scenarios are input as proportions of acres in the age class to receive each treatment.
These combinations illustrate the relative impact of thinnings, short rotations, long rotations and set asides. In each decade a marginal cost is measured as the difference in net revenue between the scenario being projected and an assumed profit maximizing scenario. As such only direct operating costs are measured. An incentive mechanism could also consider indirect costs. An environmental index is calculated on the basis of stand structure distribution.