Rangelands occupy approximately 51% of the terrestrial surface of the Earth, or 68.5 million km2 (Lean et al., 1990; Prentice et al., 1992). Rangelands include unimproved grasslands, shrublands, savannas, and hot and cold deserts. For the purposes of this assessment, tundra and improved pastures are included here, while hot deserts are described in Chapter 3. The primary use of rangelands has been and is for grazing by domestic livestock and wildlife. Rangelands support fifty percent of the world’s livestock (WRI, 1992) and provide forage for both domestic and wild animal consumption (Briske and
Heitschmidt, 1991). Rangeland management systems vary from nomadic pastoralism to subsistence farming to commercial ranching. Markets are largely externally driven, with extensive social systems in contrast to commercial agriculture. Overgrazing (the result of animal consumption exceeding carry capacity) has been and is common to rangelands throughout
the world (WRI, 1992).
Articles, citations, reports, websites, and multimedia resources focused on rangeland ecology, management, restoration, and other issues on American rangelands.