Modeling Forest Type Transitions in the Southcentral Region: Results from Three Methods
Abstract In recent years much interest has developed about the dynamics of forest type transitions, especially the transitions of land to and from southern pine plantations. This article presents 50-yr-forest type projections developed from two approaches to specifying the type transition matrices. One approach used transition matrices derived with remeasured plot data for six forest types using USDA Forest Service Forest Inventory and Analysis data. These data tracked transitions that occurred either naturally or artificially on inventory plots during one remeasurement cycle. The second approach relied on expert opinion surveys that predicted trends in the future of forest management. The transition matrices were developed from the responses regarding managers' intentions to regenerate stands following harvest. The survey was developed for the 2000 Forest and Rangeland Renewable Resources Planning Act Timber Assessment (2000 RPA). The timber inventories in eight states in the southcentral United States are projected with these methods of handling type transitions, and the results are compared to the 2000 RPA, which used a combination or hybrid approach to type transitioning. All three techniques conclude the area of planted pine is expected to increase well into the future. They are contradictory, however, in predicting the area other forest types will occupy, especially natural pine and upland hardwoods. Projections based on recent history give us one result; projections based on managers' intentions show another. South. J. Appl. For. 27(3):190–197.