white pine vs pine tree

white pine and pine tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
white pine	Yes	No	No	No
pine tree	Yes	No	No	No

As nouns, pine tree is a hypernym of white pine; that is, pine tree is a word with a broader meaning than white pine:

white pine: any of several five-needled pines with white wood and smooth usually light grey bark when young; especially the eastern white pine
pine tree: a coniferous tree

Other hypernyms of white pine include pine, true pine.

white pine (noun)	pine tree (noun)
any of several five-needled pines with white wood and smooth usually light grey bark when young; especially the eastern white pine	a coniferous tree
soft white wood of white pine trees