This last model shows the complex of forces that seal off areas from incursion in order to maintain sovereign control. Its effects on forests arise from social differentiation of opportunities among groups of people in the region of the preserve. It generally favours those with larger holdings and political power because they are in a better position to capture opportunities that the opportunities preserve creates. It forces others towards forest clearance elsewhere and poaching in the preserve. The configurations of policies specific to this system are generally contained within national strategies for public finance, internal and external boundary control, public regulations and international relations.
Forests are living systems which evolve over time with or without human intervention.
These changing forest formations create a kaleidoscopic movement of trees and land uses over space. Understanding the reasons behind these changes provides the basis for predicting the direction and consequences of future changes. Understanding how national policies affect forests provides the basis for achieving desired types of forest formations, including the aggregate contributions they provide, and the required trade-offs with other national objectives. But while the overall economic implications of national policy models are reasonably well understood, aggregate forest landscape formations have been ignored. The analytical task is to relate policy combinations to forest consequences in diverse conditions and to identify those that are likely to serve local, national and international interests in the best way.