For the InstructorThese student materials complement the Future of Food Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.
Food Systems as Coupled Natural-Human Systems
As you saw in the introductory video about a food system in Vietnam, food systems incorporate both natural and human components. In fact, because of the ubiquitous need for food, food systems are among the most important ways that human societies interact with the physical and biological elements and processes on earth's surface. Land used in some way for food production already occupies over two-thirds of the ice-free land surface (Ellis, 2011 or similar on anthromes) and the trend is for this proportion as well as for the intensity (roughly, the production from each unit of land area) to increase. Human fisheries and other forms of food production from oceans (for example, kelp farming) are also tending to exploit wider and wider areas. In addition, as seen in the multiple types of food systems presented above in section II of this unit, the interactions of human societies with earth's ecosystems in food production is not governed by a single human process but depends greatly on human priorities, land management and food production knowledge, rationales and prescriptive goals for food systems, and government policies that regulate and reward food system outcomes. Understanding these societal factors is key to improving the sustainability of food systems in their impact on the earth's ecosystems.
To understand the interaction of human societies with the earth's surface, a common and productive framework is that of coupled natural-human systems [Liu et al., 2007]. These start from a relatively simple diagram (Fig. 8.9), in which a generic human system (e.g. a community within a human society) interacts with a generic natural system (e.g. a farming-dominated landscape within a production region). The framework also recognizes that natural and human systems have many internal interactions and processes such as biogeochemical nutrient cycling (e.g. the nitrogen cycle, see unit N.N in this course) or the policies, corporate actors, and markets determining food supply chains (a human factor).
Credit: National Science Foundation Coupled Natural Human Systems research grant program
So, for example, in the video that you watched on the food system from the Red River delta in Vietnam, the river delta is the initial, broad natural system context that presents opportunities for farming, livestock production, and aquaculture to farming households and national/local government policies. Human farming/aquaculture knowledge and practices, markets and government policies are part of a human system that impacts and reorganizes the natural system over time into its current state. Over time the natural system internal interactions and processes may also change, for example, increases or decreases in soil fertility, crop pests, or animal diseases. Because of the evolution over time of the system, it is useful to reorganize the coupled natural-human system as evolving over time (Fig. 8.10).
Credit: Karl Zimmerer/Steven Vanek