“…Many current process-based models, such as FOEST-BGC (Running and Coughlan, 1988), TEM (Melillo et al, 1993), CENTURY (Parton et al, 1987(Parton et al, , 1993, PnET (Aber and Federer, 1992), TREGROW (Weinstein et al, 1991), and Hybrid v3.0 (Friend et al, 1997), are not appropriate for management applications because they are not designed to predict stand characteristic such as basal area, mean tree diameter, height, and annual mortality, and thus the outputs are not directly useful in management planning (Landsberg and Waring, 1997); Most process-based models are too complex and require a large amount of information (the number of parameter and input variables) beyond what is readily available to forest managers, making them of minimal interest to practicing foresters and forest managers (Sands, 1988;Landsberg and Coops, 1999); Most models lack a user-friendly modeling interface and their documentation is insufficient, making them difficult for forest managers to use (Peng, 2000b). Forest managers are increasingly interested in using C balance process-based approaches for assessing the sustainability of forest ecosystem productivity under short-rotation forestry and the potential effects of projected global warming and increasing atmospheric CO 2 concentration.…”