Comparison of measured and modelled growth on permanent plots in Sabahs rain forests

In this paper previously unpublished field data from 25 ha of permanent sam pling plots (PSPs) in Sabah, Malaysia, in four different forest reserves ar e analysed for mortality rates and basal area development. Field data of an observation length of 9 to 20 years were available. These data then form t he basis of several benchmark tests for the evaluation of the individual-or iented tropical rain forest growth model FORMIND. A new version of the FORM IND is presented. The model in its version FORMIND1.1 includes enhanced sub models for mortality and tree growth. The model evaluation is focused on th e model components for tree growth, competition and mortality. Data for tre e recruitment were not available. Results show a good agreement between sim ulation and held data for the main output variables basal area and stem num ber indicating a reasonable behaviour of the model components we focused on . Furthermore the results show that differences in site conditions influenc e tree growth and mortality. Site characteristics should be included in the model in the future. (C) 2001 Elsevier Science B.V. All rights reserved.