This book addresses methodological issues of production ecology, and contains scientific contributions written by nine specialists. A central issue is the combination of the agricultural model with reliable data in relation to scale. A model is developed with data from a single point, whereas decisions are to be made for areas of land. Such an approach requires the use of a skilful treatment of available data and information. The book is divided into four parts. Advanced information science yields the best possible models in an efficient way. Geographical Information Systems combine various layers of spatial information. Statistics upscale local information towards regions and test its reliability. Modern trends in automated modeling are identified. The book is illustrated with various practical studies, ranging from the individual model to the whole European Community. It aims at a readership of graduate and post-graduate agricultural scientists, practitioners and politicians.