quadrat vs terrain

quadrat

noun
  • An area of land, marked for studying its plants, animals, soil, natural processes, etc. 

  • A virtual rectangular subdivision of a line or column of hieroglyphs within which a group of hieroglyphs is arranged. 

terrain

noun
  • An area of land or the particular features of it. 

  • The surface of the earth; the ground. 

  • A single, distinctive rock formation; an area having a preponderance of a particular rock or group of rocks. 

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