Comparative Ecology of Native and Introduced Ungulates

摘要: The defining period of coevolution among Great Plains plant and ungulate species occurred during the past 12,000 years (Mack Thompson 1982, Axelrod 1985). In late Pleistocene early Holocene, a diverse array large grazers browsers were reduced to much smaller group represented by bison (Bison bison), pronghorn (Antilocapra americana), deer (Odocoileus hemionus O. virginianus), elk (Cervus canadensis). These changes in presence nomadic humans from Asian steppe who immigrating same time. landscape was characterized gently rolling interfluvial surfaces covered with perennial herbaceous vegetation. exposed grasslands periodically interrupted more protected wetland, riparian woodland, or scarp woodland habitats. Although wetlands woodlands occupied less than 7 3% Plains, respectively (National Wetlands Inventory, Nebraska Natural Heritage Program data bases), heterogeneity that they created at scales played major role determining distribution abundance native ungulates. Extreme cold heat, drought, flood, fire, wind, countless biotic interactions caused locally short-term fluctuations populations long-term shifts features. dynamic temporal overlayed on multi-scale spatial mosaic. Native ungulates adapted this landscape.