A managerial advisory system, ASSG, for the hilly, sandy grassland ecosystems in North China was developed. The system combined the empirical knowledge of local experts of ecosystem management and the theoretical research results on soil water dynamics to develop optimal managerial strategies for land use, plant species/variety selection, and optimal coverage of plants. A three-phase interactive inference procedure, together with structured knowledge bases, was used to guide users through the consultation process step-by-step. At each phase of the inference process, users are provided with multiple options; the next inference phase is selected based on users' choice in the current phase. This interactive scheme of inference gives users maximum flexibility to obtain appropriate consultation results.
The main body of the system was coded in Turbo Prolog, a descriptive language for expert system development. The optimal plant coverage model, based on soil water dynamics, was coded in Turbo C and imbedded into the main body of the system. The sample consultation runs of the system indicated that the system operated smoothly and was able to develop useful managerial strategies for sandy grasslands in North China.