Bison, anthropogenic fire, and the origins of agriculture in eastern North America

Scholars have argued that plant domestication in eastern North America involved human interactions with floodplain weeds in woodlands that had few other early successional environments. Archeological evidence for plant domestication in this region occurs along the Mississippi river and major tributaries such as the Tennessee, Ohio, Illinois, Missouri, and Arkansas rivers. But this region is also known as the prairie peninsula: a prairie-woodland mosaic that was maintained by anthropogenic fire starting as early as 6000 BP. Contrary to conventional wisdom, recent research has shown that bison were also present in the prairie peninsula throughout the Holocene. Recent reintroductions of bison to tallgrass prairies have allowed ecologists to study the effects of their grazing on this ecosystem for the first time. Like rivers and humans, bison create early successional habitats for annual forbs and grasses, including the progenitors of eastern North American crops, within tallgrass prairies. Our fieldwork has shown that crop progenitors are conspicuous members of plant communities along bison trails and in wallows. We argue that ancient foragers encountered dense, easily harvestable stands of crop progenitors as they moved along bison trails, and that the ecosystems created by bison and anthropogenic fire served as a template for the later agroecosystem of this region. Without denying the importance of human-river interactions highlighted by previous researchers, we suggest that prairies have been ignored as possible loci for domestication, largely because the disturbed, biodiverse tallgrass prairies created by bison have only been recreated in the past three decades after a century of extinction.