Historical northeastern forested boundary of the Great Plains grasslands in the United States

Precise definition of the Great Plains grasslands has defied consensus, but historical vegetation reconstruction can provide a more authoritative boundary of the ecotone between the Great Plains and eastern forests. After comparing Great Plains boundaries, an eastern boundary was developed using evidence from historical tree surveys during the 1800s. The definition differs from others by including Illinois and small sections in Indiana and Wisconsin, but excluding Missouri due to regular tree presence overall at landscape scales, resulting in an extent of 2.29 million square kilometers in 15 states. Establishing the historical eastern boundary based on historical tree surveys contributes a solution to the debate over competing versions of the Great Plains. This data publication provides this historical boundary as a shapefile.
Develop an eastern boundary to the Great Plains using historical tree surveys.