The future of production systems in a globalized world

© The Ecological Society of America www.frontiersinecology.org H life is ultimately dependent on ecosystem services supplied by the biosphere, including agricultural production, flood control, and recreational opportunities. Over the past 50 years, humans have changed ecosystems more rapidly and more extensively than at any other time in human history, primarily to meet the growing need for provisioning ecosystem services such as food, freshwater, and timber (MA 2005). Cultivated systems now cover one-quarter of Earth’s terrestrial surface (Hassan et al. 2005; Figure 1). The amount of water impounded behind dams has quadrupled since 1960 (MA 2005). Global production of wood has increased 60% in the past four decades, to a total of 3.1 billion cubic meters in 2005 (FAO 2006). Since 1960, flows of biologically available nitrogen (N) in terrestrial ecosystems have doubled, and flows of phosphorus (P) have tripled, largely due to efforts to increase food production through fertilization (Vitousek 1997; Bennett et al. 2001). While these and other changes have enabled highly efficient production of particular ecosystem services (primarily food, feed, and fiber), they also radically alter provision of other ecosystem services, both now and in the future, usually by diminishing them. For example, deforestation to increase timber and agricultural production is one of the most important drivers of mounting species extinction rates, which are now 1000 times higher than in the fossil PRODUCTION SYSTEMS PRODUCTION SYSTEMS