Preface from \u3ci\u3eThe Changing Prairie: North American Grasslands\u3c/i\u3e

North American grasslands have figured prominently in our North American heritage. Prairies first provided significant barriers to westward expansion, and then offered both economic and sociological opportunity, as well as heartache, for settlers. Many artists have gained significant inspiration from the beauty as well as the harshness of this region and its biota. And because of ideal climate and soil conditions, these grasslands have provided the agricultural foundation of which much of the economic growth and stability of the United States has historically depended. Yet many see North American prairies as beautiful only when manipulated or exploited: Green croplands or manicured park lawns are attractive; native grasslands are “those ugly weeds.” In the past, plowing virgin prairie could be easily defended on both economic and sociological grounds. And, historically, North American prairies must have seemed threatening in both their wildness and their endlessness. The preservation of remaining North American prairies is now an urgent need. Many existing prairie types can be considered as threatened as or more threatened than tropical forests. No tallgrass prairie was saved in the sense of maintaining widely ranging species that link patches and regions (bison, elk, wolves); only plants remain as a reasonable legacy of this past system. Midgrass prairie has been almost completely plowed. More of western shortgrass prairie remains, but present human activity is exacting great stress on this ecosystem. The California grasslands, historically dominated by perennial bunchgrasses, were nearly fully invaded by annual grasses from the Mediterranean region; exotics nearly replaced native species in about half a century, leading to a significant impact on grassland dynamics. In sum, North American grasslands are a vanishing resource