moorland vs champaign

moorland and champaign both are nouns.

Word	Noun	Adjective	Verb	Adverb
moorland	Yes	No	No	No
champaign	Yes	No	No	No

As nouns, champaign is a hypernym of moorland; that is, champaign is a word with a broader meaning than moorland:

moorland: open land usually with peaty soil covered with heather and bracken and moss
champaign: extensive tract of level open land

Other hypernyms of moorland include field, plain.

moorland (noun)	champaign (noun)
open land usually with peaty soil covered with heather and bracken and moss	extensive tract of level open land