pasture vs rangeland

pasture

noun
  • Land, specifically, an open field, on which livestock is kept for feeding. 

  • Ground covered with grass or herbage, used or suitable for the grazing of livestock. 

verb
  • To move animals into a pasture. 

  • To graze. 

  • To feed, especially on growing grass; to supply grass as food for. 

rangeland

noun
  • unimproved land that is suitable for the grazing of livestock 

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