Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 3/8/2008
Publication Date: 6/1/2009
Citation: Sanderson, M.A., Wedin, D., Tracy, B. 2009. Grasslands: Definition, Origins, Extent, and Future. In: Wedin, W.F., Fales, S.L., editors. Grassland Quietness and Strength for a New American Agriculture. Madison, WI: Crop Science Society of America. P. 57-74. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Grassland, as an ecological land type, is defined as “land on which the vegetation is dominated by grasses.” The ecological basis for these land types depends on climatic factors including temperature and soil moisture. Early European explorers encountered diverse grassland types across North America. These treeless regions included coastal sandplain grasslands on the Atlantic and Gulf coasts, scattered open meadows and prairies throughout the eastern forest region, mid-elevation parklands in the mountains of the arid west, inter-montane grasslands of the Pacific and Great Basin states, and the Peace River parklands of northern Alberta. The prehistoric origins of these grasslands were also diverse, reflecting the influence of topography, climate, fire, grazing animals, and pre-European Native Americans. Not only do these lands produce food and fiber for humans, but these lands also provide many ecosystem services upon which humans depend. Such ecosystem services include soil erosion control, soil fertility improvement, water conservation and protection, wildlife habitat, pollution buffers, recreational uses, biofuel production, and an agricultural system termed grassland agriculture. Even though public awareness of grassland conservation has increased dramatically in recent decades, native grasslands continue to be lost to development, encroachment of woody vegetation, and agriculture. Managing grassland multi-functionality will become increasingly important in the future because of a growing population, environmental concerns, and ever-tightening energy supplies. In this chapter we define and describe grasslands in the U.S. in terms of land type, land use, vegetation, distribution, and area. Then we take a long look back through geologic time and consider what we know about the distribution of grasslands and their species composition in North America. Last, we look ahead to consider the future of grasslands and their use in traditional ways, such as forage for livestock, and in new ways, such as bioenergy crops and as carbon sinks.