In this unit, students help maintain the local food system by discovering and then explaining why a single garden plot is failing within an otherwise thriving community garden. Students model how, even in human systems, producers, consumers and decomposers cycle matter and energy within and between ecosystems. As part of their investigation, students delve deeply into how producers, like vegetables, make food out of “thin air” through photosynthesis. Eventually students use their model to recommend strategies to return the garden plot to its former glory.