heartland vs wilderness

heartland

noun
  • The central part of a region defined by geographical or non-geographical criteria, such as support for a political party, faith or similar. 

  • The part of a region considered essential to the viability and survival of the whole. 

wilderness

noun
  • Often preceded by in the: a situation of disfavour or lack of recognition; (specifically, politics) of a politician, political party, etc.: a situation of being out of office. 

  • Chiefly followed by of: a bewildering flock or throng; a large, often jumbled, collection of things. 

  • An ornamental part of a garden or park cultivated with trees and often a maze to evoke a natural wilderness. 

  • Uncultivated and unsettled land in its natural state inhabited by wild animals and with vegetation growing wild; (countable) a tract of such land; a waste or wild. 

  • A place other than land (for example, the air or sea) that is uncared for, and therefore devoted to disorder or wildness. 

  • A place or situation that is bewildering and in which one may get lost. 

How often have the words heartland and wilderness occurred in a corpus of books? (source: Google Ngram Viewer )