bast fiber vs natural fiber

bast fiber and natural fiber both are nouns.

Word	Noun	Adjective	Verb	Adverb
bast fiber	Yes	No	No	No
natural fiber	Yes	No	No	No

As nouns, natural fiber is a hypernym of bast fiber; that is, natural fiber is a word with a broader meaning than bast fiber:

bast fiber: strong woody fibers obtained especially from the phloem of from various plants
natural fiber: fiber derived from plants or animals

Other hypernyms of bast fiber include natural fibre.

bast fiber (noun)	natural fiber (noun)
strong woody fibers obtained especially from the phloem of from various plants	fiber derived from plants or animals