Floral Migration and Death of Megafauna in the Archaic Period
12 Major Pollen Groups of Trees and Their Concentrations. Image Courtesy of Global Climates by H.E Wright.
Migrating Boreal Forest from 21000 to 12000 Years Before Present. Image Courtesy of NASA Earth Observatory.
Migrating Boreal Forest from 9000 Years Before Present to Present Day. Image Courtesy of NASA Earth Observatory.
Regional Climate Change Influences Migration of Trees
The change in climates within regions would eventually influence the northward migration of trees associated with cooler temperatures. Coupled with manipulation by the people, trees such as spruce, birch, fir, hemlock, and alder started to make their way northward as early as 12,000 years BP. Regional forests saw a spike in Oaks by 11,000 years BP. Pine, elms, and maple were also intermingled within forest composition. By the time the Early Archaic period came to an end around 8,900 BP, trees associated with colder climates had completely migrated out of the area; some pines migrated southward; and oaks had completely dominated the area.Â
Artists Illustration of Mastadon Hunting by Peoples in Paleoindian Period. Image Courtesy of Illinois State Museum.
Death of the Megafaunas Affect on the Environment
Even with the absence of these trees, the oak-hickory-pine and oak-hickory forest were still able to support its animal inhabitants—turkeys, squirrels, deer, blue jays, and among other species were able to survive off the nuts and seeds dropped from these trees. And because of this ever evolving climate and landscape, fauna were affected as well. The disappearance of mammoths and mastodons by 12,200 years BP greatly changed the ecosystem. The absence of trampling, grazing, and browsing of small trees and shrubs produced a whole new change within the plant and animal community. With the absense of the large-bodied plant eaters, the forests were left unchecked and overtook some grassland areas. Animals such as the eastern gray squirrel, common possum, marsh rice rat, wood rat, and the common swamp rabbit were inhabiting the area as early as the Late Holocene Period (around 4,500 years BP).