EVALUATING PERFORMANCE OF AN APPALACHIAN OAK FOREST DYNAMICS MODEL

An Appalachian-oak forest in a small montane watershed was sampled to calibrate and test an existing forest dynamics simulation model. Indices developed in earlier studies by Whittaker were used to estimate the response of different tree species to soil moisture. As is the case in many forest modeling applications, neither detailed environmental data at a micro-spatial scale nor quantitative historical stand data were available for the study. A protocol of both model parameter estimation and simulation output evaluation is developed. The method involves simulation experiments under which the model parameters are allowed to vary systematically with respect to environmental control variables, allowing one to generate a field of potential simulation results that can be searched for patterns shared by the observed data. The degree to which common patterns emerge provides a measure of model sensitivity to patterns at the scale of interest. This protocol can provide an appraisal of the appropriateness of a simulation model to the system of interest and can be used to assess the performance of the model in future applications. © 1990 Kluwer Academic Publishers.