The scheme for globalization of a process-based model explaining gradations in terrestrial NPP and its application

It is more or less obvious that a process-based net primary production (NPP) model tested for a stand can be applied over a global grid, but doing so, we face the problem-how to calibrate it at this scale. In this paper we demonstrate a scheme for such calibration with a process-based NPP model. First, we suggest that model parameters should be derived from a freely accessible database of NPP measurements. Then, we reduce the number of undefined model parameters to a single lumped parameter (SLP) and rind its value for each database entry. Next, considering SLP as some characteristic of vegetation, we formulate an empirical model linking SLP and climate. And finally, we globalize the process-based model in hand by assigning SLP value to the nodes of geographical grid proceeding from the global fields of climatic variables. (C) 2002 Elsevier Science B.V. All rights reserved.