Work by many international, regional and national institutions and pressure groups has developed numerous sets of criteria and indicators (C&I) for "sustainable forest management". However, in the absence of reliable techniques to interpret forest inventories these C&I remain subjective. In order to develop reliable, relevant and cost-effective indicators, we need to be able to model the response of tropical forests to a variety of management options. Appropriate models should firstly confirm that any particular management regime is sustainable in the long term, and secondly assist in the identification of suitable indicators for monitoring such a regime. Conventional models of growth and yield are inadequate when used to evaluate the ecological and economic sustainability of forest systems. The development of combined models of yield, economics and environmental impact are urgently required for the development of sustainable forest management and associated certification schemes.

Appropriate indicators of ecological and economic sustainability developed and promoted.

• A novel modelling framework for physiologically-based growth and yield prediction will be developed to utilise existing sources of inventory and PSP data. This will be integrated with a permanent sample plot database for Kalimantan (Indonesia) as a model system that can simply be applied in other regions.
• The modelling framework will be applied to PSP data and linked to economic data at forest management unit level within the developing concept of the KPHP in Indonesia. This will be used to evaluate ecological and economic criteria and indicators of sustainable forest management. These will be developed and promoted in collaboration with staff from CIFOR.