The Tallgrass Prairie Mosaic

Abstract

Grasslands are biological communities in which the landscape is dominated by herbaceous vegetation, especially grasses: they contain few trees or shrubs. An estimated 16 to 40% of the world’s land surface is, or was, covered by grasslands (Singh et al. 1983, Burton et al. 1988, Groombridge 1992). Area estimates of current savanna and temperate grasslands are from 16.1% to 23.7% of the world’s land area (Groombridge 1992). Notable examples include prairies of North America, llanos of northern South America, cerrados and campos of Brazil, pampas of Argentina, steppes of central Asia, veldt and savannas of Africa, and grasslands of Australia. Grasslands are the largest vegetational unit in North America, covering approximately 20% of the land area, and prairies are the most abundant type of grassland on the continent (Kuchler 1964, Risser et al. 1981, Burton et al. 1988). Prior to European settlement, prairies occupied a more or less continuous (except at the fringes), roughly triangular shaped area covering 3.6 million square km. The base extended for 3,900 km along the foothills of the Rocky Mountains from the Canadian provinces of Saskatchewan and Manitoba southward through New Mexico into Texas (Figure 3.1). The apex of the triangle, the prairie peninsula (Transeau 1935), extended 1,600 km eastward into the Midwest and included the prairies of Illinois, Iowa, Indiana, Minnesota, Missouri, and Wisconsin, with scattered outliers in southern Michigan, Ohio, southwestern Ontario, and Kentucky (Risser et al. 1981; Madson 1982; Farney 1980; Weaver 1954, 1968; Whitney and Steiger 1985) (Figure 3.1). This chapter focuses on this eastward projection of tallgrass prairie around what is known as the prairie peninsula (Transeau 1935).