Agro-ecological knowledge at different scales.

Scale is a real and quantifiable phenomenon, not just a conceptual construct. Characteristics of agro-ecological processes depend on scale. Observed ecological heterogeneity in the field may often result from inadequate data resolution. Scaling up or down depends on a proper identification of different processes that are specific to each scale, and differs from a cumulation of lower or higher scale data or variables. There is an optimal scale level at which each process can and must be studied. In order to improve scale-sensitivity in agro-ecological research key processes must be identified that provide an entry into linking scales together. Possible ‘hidden effects’ of agricultural technology at other scale levels than the one at which technology aims, present a special analytical challenge.