Alternative Projections of the Impacts of Private Investment on Southern Forests: A Comparison of Two Large-Scale Forest Sector Models of the United States

of the impacts of private investment on southern forests: a comparison of two large-scale forest sector models of the United States. Silva Fennica 35(3): 265–276. The TAMM/NAPAP/ATLAS/AREACHANGE (TNAA) system and the Forest and Agri-culture Sector Optimization Model (FASOM) are two large-scale forestry sector modeling systems that have been employed to analyze the U.S. forest resource situation. The TNAA system of static, spatial equilibrium models has been applied to make 50-year projections of the U.S. forest sector for more than 20 years. Much of its input on forest management behavior and decisions about use of forestland derives from expert-based systems external to the TNAA system. FASOM, a spatial intertemporal optimization model, directly incorporates decisions on management investment and land use options relative to agricultural alternatives as endogenous model elements. The paper contrasts projections of private forest investment from the TNAA and FASOM models, focusing on the southern United States. Comparison of the TNAA base case and an investment-restricted scenario from FASOM, both of which refl ect a continuation of recent behavioral tendencies by nonindustrial private owners, suggests that Southern private timberland