'Neutral zone' definitions:

Definition of 'Neutral zone'

From: GCIDE
  • Transition zone \Tran*si"tion zone\ (Biogeography) The zone lying between the Boreal and Sonoran zones of North America. It includes an eastern or humid subdivision and a western arid one of corresponding temperature comprising the northern Great Plains and the lower slopes of the mountains of the western United States and Mexico. Called also {Neutral zone}. [Webster 1913 Suppl.]