should be trees which are tall. Long trees would be tall ones laying on the ground.
Well, I think also the latter would be translated the same way ... but yeah, it's much less likely that you'd talk about someone climing felled trees.
-refu is translated as tall elsewhere (you don't have long people or giraffes), why not here? Upright things are tall, horizontal things are long. You don't climb horizontal things.
I find it interesting that planting trees and climbing trees would be said the same way? Is there a way to distinguish the two?
That's my question, too. One could transplant trees that are already tall.