ecosphere vs ecosystem

ecosphere

noun
  • the biosphere 

  • The portion of the atmosphere from sea-level to about 4000 meters in which it is possible to breathe without technological assistance. 

ecosystem

noun
  • The interconnectedness of organisms (plants, animals, microbes) with each other and their environment. 

  • A system formed by an ecological community and its environment that functions as a unit. 

  • A network of interconnected people or organisations that resembles a natural ecosystem due to the complex interdependencies. 

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