Contributed by Stephen Polasky, March 27, 2014 (sent for review July 12, 2013)
Land-use change affects the provision of ecosystem services and wildlife habitat. We project land-use change from 2001 to 2051 for the contiguous United States under two scenarios reflecting continuation of 1990s trends and high crop demand more reflective of the recent past. These scenarios result in large differences in land-use trajectories that generate increases in carbon storage, timber production, food production from increased yields (even with declines in cropland area), and >10% decreases in habitat for one-quarter of modeled species. We analyzed three policy alternatives that provide incentives to maintain and expand forest cover, conserve natural habitats, and limit urban sprawl. Policy interventions need to be aggressive to significantly alter underlying land-use trends and shift the trajectory of ecosystem service provision.
Providing food, timber, energy, housing, and other goods and services, while maintaining ecosystem functions and biodiversity that underpin their sustainable supply, is one of the great challenges of our time. Understanding the drivers of land-use change and how policies can alter land-use change will be critical to meeting this challenge. Here we project land-use change in the contiguous United States to 2051 under two plausible baseline trajectories of economic conditions to illustrate how differences in underlying market forces can have large impacts on land-use with cascading effects on ecosystem services and wildlife habitat. We project a large increase in croplands (28.2 million ha) under a scenario with high crop demand mirroring conditions starting in 2007, compared with a loss of cropland (11.2 million ha) mirroring conditions in the 1990s. Projected land-use changes result in increases in carbon storage, timber production, food production from increased yields, and >10% decreases in habitat for 25% of modeled species. We also analyze policy alternatives designed to encourage forest cover and natural landscapes and reduce urban expansion. Although these policy scenarios modify baseline land-use patterns, they do not reverse powerful underlying trends. Policy interventions need to be aggressive to significantly alter underlying land-use change trends and shift the trajectory of ecosystem service provision.
Author contributions: J.J.L., D.J.L., E.N., A.J.P., S.P., J.C.W., and V.C.R. designed research; E.N., A.J.P., J.C.W., D.P.H., S.M., and D.P. performed research; J.J.L., D.J.L., E.N., A.J.P., S.P., J.C.W., and V.C.R. analyzed data; and J.J.L., D.J.L., E.N., A.J.P., S.P., J.C.W., S.M., and V.C.R. wrote the paper.
The authors declare no conflict of interest.
Data deposition: A land use/land cover database exists at the SILVIS Laboratory at the University of Wisconsin–Madison. Contact D.P.H. or V.C.R. for information about accessing the data.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1405557111/-/DCSupplemental.
