timberland vs tree farm

timberland and tree farm both are nouns.

Word	Noun	Adjective	Verb	Adverb
timberland	Yes	No	No	No
tree farm	Yes	No	No	No

As nouns, tree farm is a hyponym of timberland; that is, tree farm is a word with a more specific, narrower meaning than timberland:

timberland: land that is covered with trees and shrubs
tree farm: a forest (or part of a forest) where trees are grown for commercial use

Other hyponyms of timberland include greenwood, riparian forest, silva, sylva.

timberland (noun)	tree farm (noun)
land that is covered with trees and shrubs	a forest (or part of a forest) where trees are grown for commercial use