ABSTRACT
Although highly valuable, this is only a denition of a sustainable agroecosystem-and a broad and formal one at that. It is a different matter to point to an actually existing agroecosystem and identify it as sustainable or not and determine why, or to specify exactly how to build a sustainable system in a particular bioregion and sociocultural context. Generating the knowledge and expertise for doing so is one of the main tasks facing the science of agroecology today, and is the subject to which this chapter is devoted.
