Yukon white birch vs birch tree

Yukon white birch and birch tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Yukon white birch	Yes	No	No	No
birch tree	Yes	No	No	No

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

Yukon white birch: Alaskan birch with white to pale brown bark
birch tree: any betulaceous tree or shrub of the genus Betula having a thin peeling bark

Other hypernyms of Yukon white birch include birch.

Yukon white birch (noun)	birch tree (noun)
Alaskan birch with white to pale brown bark	any betulaceous tree or shrub of the genus Betula having a thin peeling bark