Operational models of economic activity, particularly at the farm scale, have become commonly used, and widely accepted methods and applications exist. Operational models of ecological systems have less of a history but processes of species interaction and succession are well documented. Relationships between economic farm-scale variables and resultant ecological diversity, however, are less well documented as are modelling frameworks which combine both economic and ecological operational systems. This paper demonstrates an innovative methodology linking a utility maximising economic model with an ecological modelling system allowing ex ante assessments of the ecological impact of certain key agricultural management parameters. The two models, initially designed for independent analyses, are introduced and their synthesised application is demonstrated. Data pertaining to a survey of farm sites is used to demonstrate the types of relationships which emerge between agricultural management parameters and grassland vegetation, and to validate preliminary model results. A farm-specific ecological-economic assessment is then presented, using the modelling framework under potential policy scenarios. The results of the analysis highlight the relevance of such an integrated modelling system for environmental policy decision support.