bast fiber vs natural fibre

bast fiber and natural fibre both are nouns.

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

As nouns, natural fibre is a hypernym of bast fiber; that is, natural fibre 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 fibre: fiber derived from plants or animals

Other hypernyms of bast fiber include natural fiber.

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