Table 2. The relationships among different drivers and outcomes (Fig. 1) of land use in the Corn Belt social-ecological system.

Interaction Description References
Climate, Topography, and Soils  arrow Land Cover and Hydrology Basic ecological relationships facilitate and constrain interactions among other aspects of the system. The Corn Belt has a temperate climate and deep glacial soils, making it one of the most versatile agricultural regions in the world. Based on soil and topographical patterns, different landscape positions are better suited to different agricultural and conservation uses. Future global climate change may impact average temperature and precipitation, weather severity, and the regional fit of different cover types in ways that are difficult to predict. Alley et al. 2003, Schulte et al. 2006, Millar et al. 2007
     
Policy inline image Markets
inline imageTechnology
U.S. federal farm policy is designed, in part, to impact the markets of different kinds of crops. In recent decades, a high proportion of federal support for farms has been directed to create price supports for production of commodity row crops such as corn and soybeans. Federal regulations and subsidies can also be instrumental in helping to spur new technologies and markets, e.g., corn-based ethanol. Workshop Data; Keeney and Kemp 2002
     
Technologyinline imageHydrology, Land Cover, Infield Care Agricultural and environmental technologies influence what is possible in land use and care. Currently, emerging technological pathways associated with different types of bioenergy production are influencing new patterns in land cover and care, which in turn enhance or erode ecological outcomes. The region’s hydrologic structures are collectively managed entities that have been altered over decadal time frames through changes in technology, policy, institutions, and cultural norms. Workshop Data; Landis et al. 2008, Atwell et al. 2009b, Porter et al. 2009
     
Markets and Policydownarrow Rural Demographics Over the last several decades, declining crop prices and increasing input costs have lowered farmers’ terms of trade leading to the need for operators to farm more land to make a living. Although agricultural policies have provided funding to support the agricultural system, most of this money supports large-scale commodity crop farms, e.g., corn and soybeans, and land owners, who may not live in rural areas. This has led to fewer farmers in rural areas, an increase in average farmer age, and a decrease in population, numbers of young farmers, commerce, and connectedness in rural communities. Heady et al. 1965, Keeney and Kemp 2002, EWG 2006, Lobao and Stofferahn 2007
     
Technology, Markets, and Farm ProfitabilitydownarrowFarmer Decisions Changing markets and emerging technologies influence farmers’ land use decisions. To make a living, farmers must be attentive to the profitability of their farms. If new agricultural and conservation practices are to be adopted at broad scales, they must be profitable and fit with current technological and market trends in agriculture. McCown 2005, Atwell et al. 2009a,b
     
Federal Farm PolicydownarrowFarmer Decisions Federal farm policy has been shown to influence farmer decisions in many ways. Commodity and conservation subsidies have had widespread impacts on land use at broad scales. The ways in which policies are funded and implemented at local levels can also play a key role in mediating enforcement of regulations and farmers’ participation in incentive programs. Long-term, consistent, and straightforward programs that are compatible with farm practices, priorities, and profitability are more likely to elicit high participation. Workshop data; Keeney and Kemp 2002, McCown 2005, Atwell et al. 2009a,b
     
Rural DemographicsdownarrowCommunity Norms and Network; Farmer Decisions Changing demographics, including loss of people, especially young farmers, from the land and decline in community commerce and vitality, impacts the quality and connectedness of life in rural communities. Because many farmers are nearing retirement and do not know who will farm their land after them, they are reticent to make major changes in their farming practices. Corn Belt stakeholders emphasized that potential for change in other aspects of the system hinges upon bolstering the vitality of the region’s struggling rural communities. McCown 2005, Jordan et al. 2007, Morton 2008, Atwell et al. 2009a,b
     
Regional InstitutionsdownarrowAgricultural Technology, Markets, and Federal Farm Policy Agricultural and conservation interests in the Corn Belt, including policy makers, government agencies, and large nonprofit and lobby groups, have an influence on federal farm policy. Our workshop participants indicate that these regional institutions have the potential to influence the development of new markets and technologies to empower agricultural land uses that can achieve desired outcomes. Workshop Data; Keeney and Kemp 2002
     
Regional InstitutionsvertarrowsCommunity Norms and Networks inline imageFarmer Decisions Farmers’ decisions are based upon many factors that operate at several different scales, and are not purely rational economic evaluations. The interaction among community social norms and networks and regional institutions, e.g., societal laws and customs, government agencies, nonprofit organizations, agricultural and conservation groups, can play a key role in mediating the influence of macroscale markets, technologies, and policies on farmers’ land use values and decisions. Workshop Data; Fliegel and Korsching 2001, Ajzen 2005, McCown 2005, Morton 2008, Atwell et al. 2009a,b, 2010
     
Hydrologyinline imagePerennial Coverup arrow Infield Care Underground networks of pipelines drain wetlands to increase cropping efficiency, while channelized streams remove water from the landscape during wet seasons and create more land for crops. These hydrologic alterations also increase soil loss and flood severity and deliver water-bound nutrients, like nitrate-nitrogen, directly into regional waterways where they cause prolific algal growth and hypoxia. The amount, position, type, and quality of perennial cover has been shown to impact regional biodiversity, water quality, and other ecosystem services, in part by uptake of extra nutrients. To achieve these outcomes, implementation of practices must be coordinated across landscapes. Best et al. 1995, Crumpton 2001, Keeney and Kemp 2002, Schultz et al. 2004, Schulte et al. 2006, Jordan et al. 2007, Nassauer et al. 2007, Hatfield et al. 2008, Schulte et al. 2008, Porter et al. 2009
     
Institutions, Community Norms and Networks, Farmer Decisionsinline imageHydrology, Perennial Cover, and Infield Care Because 90% of the land in the Corn Belt lies in privately owned and operated farms, the form and function of landscape-scale hydrological systems and vegetation patterns hinge upon the collective decisions and careful management of farm owners and operators. Social norms and the involvement of regional institutions such as agriculture and conservation nonprofit organizations or government agencies, in community networks also interplay with farmer decisions to impact hydrology, land use, and land care at landscape scales. Workshop Data; USDA NASS 2004, Morton 2008, Atwell et al. 2009a,b, 2010
     
Hydrology, Perennial Cover, Infield Careinline imageCarbon Sequestration,
Soil and Water Quality, Flooding, Biodiversity
Building soil quality, carbon sequestration, biodiversity, and controlling the loss of water and nutrients from the land, require attention to the interaction between hydrology, and the amount, type, position, and quality of perennial cover in agricultural landscapes. To achieve these outcomes, landscape-scale planning and careful management of both hydrologic structures and infield cropping systems is essential. Workshop Data; Crumpton 2001, Schultz et al. 2004, Schulte et al. 2006, Jordan et al. 2007, Nassauer et al. 2007, Hatfield et al. 2008, Landis et al. 2008, Broussard and Turner 2009
     
Perennial Vegetation inline image Carbon Sequestrationing inline image Climate Change Forests, grasslands, and other forms of vegetative cover are instrumental in absorbing carbon from the atmosphere and offsetting the effects of greenhouse gas emission on global climate change. When compared to either corn-based ethanol or soy biodiesel, biofuels made from diverse perennial mixtures have been shown to sequester more carbon, produce greater energy per unit area, and lead to greater reductions in green house gas emissions. Tilman et al. 2006, Millar et al. 2007
     
Water, Wildlife, and Biodiversityinline image Recreation and Aestheticsinline image Rural Vitality Both social and economic benefits have the potential to be realized through landscape change targeting biodiversity. Regional counties that include, or are surrounded by, natural amenities such as green belt trails, preserves, and lakes are increasing in per capita income. Rural residents in a large agricultural watershed in the Upper Midwest assign high value to living in a healthy environment, conserving natural resources for future generations, and experiencing a serene and peaceful natural environment. Stein et al. 1999, Santelmann et al. 2004, Monchuck et al. 2007