Estimates of the distributions of forest ecosystem model inputs for deciduous forests of eastern North America

Techniques for evaluating uncertainties in process-based, computer simulati on models are evolving in response to the proliferation of such models and the demand for their use in the management of forest ecosystems. Many evalu ation techniques require precise statements of the uncertainties associated with each model input. Statements of uncertainty are typically formulated as probability density functions (pdfs). Here, pdfs are developed for 29 in puts of the process-based, forest ecosystem, computer simulation model PnET -II, many of which are inputs to other well-known forest ecosystem models. The inputs considered describe vegetation characteristics of forests typica l of the Eastern Deciduous Forest biome of North America. Data were compile d largely from published literature to estimate pdfs. The compiled distribu tions can be used to conduct various model evaluations including uncertaint y assessment, calibration, and sensitivity analysis.