preservationist vs meliorist

preservationist and meliorist both are nouns.

Word	Noun	Adjective	Verb	Adverb
preservationist	Yes	No	No	No
meliorist	Yes	No	No	No

As nouns, meliorist is a hypernym of preservationist; that is, meliorist is a word with a broader meaning than preservationist:

preservationist: someone who advocates the preservation of historical sites or endangered species or natural areas
meliorist: a disputant who advocates reform

Other hypernyms of preservationist include crusader, reformer, reformist, social reformer.

preservationist (noun)	meliorist (noun)
someone who advocates the preservation of historical sites or endangered species or natural areas	a disputant who advocates reform