physiology vs phytogeography

physiology

noun
  • A branch of biology that deals with the functions and activities of life or of living matter (as organs, tissues, or cells) and of the physical and chemical phenomena involved. 

phytogeography

noun
  • The science that studies the geographical distribution of plants; geobotany 

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