Land use in the United States has always been marked by change — forest has become cropland and then returned again; towns have grown in rural areas only to disappear; cities have grown, suburbs have spread. In the last 25 years, however, change has accelerated in ways that depart from previous trends, even as the stakes have gotten higher — land use can have real effects on climate change, wildlife habitat and now even energy production.
A 2008 paper by researchers from Harvard University, Oregon State University, and the U.S. Department of Agriculture, “What Drives Land-Use Change in the United States? A National Analysis of Landowner Decisions,” quantifies the relative importance of economic and policy drivers of land-use change at the national level.
The paper’s authors find that:
- Total cropland area had exhibited a downward trend since 1978. Between 1945 and 2002, the most consistent trends in major uses of land have been a growth in special-use and urban areas and a decline in total grazing lands.
- Cropland declined due to falling net returns and the effects of the federally financed Conservation Reserve Program (CRP), under which landowners are paid for retiring environmentally sensitive land from cultivation.
- Direct federal farm payments, which increase cropland, were more than offset by cropland retirement under the CRP.
- Forest areas increased mainly due to the rise in timber net returns and declining crop net returns.
- Urban land increases were mainly due to urban net returns.
Overall, the authors state, private land-use decisions were mainly influenced by land quality and expected economic returns to alternative uses. The paper concludes by discussing some of the implications on public policies, including on carbon sequestration and the rate of urbanization.
Keywords: conservation, rural, sprawl