LotR -- Book 3 - Chapter 04 - Treebeard

[Tuor of Gondolin]

The difference in forests in the bulk of Middle-earth, as opposed to
Beleriand and Numenor- which hold no apparent significant evil-
is interesting, Fangorn's etc. evil due to the influence of Morgoth and Sauron?

For example, about the Bay of Eldanna:

All about that place, up the seaward slopes and far into the land, grew the evergreen and fragrant trees that they brought out of the West, and so throve there that the Elder said that almost it was fair as a haven of Eressea. They were the greatest delight of Numenor, and they were remembered in many songs long after they had perished for ever, for few ever flowered east of the Land of Gift: oiolaire and lairelosse, nessamelda, vardarianna, taniquelasse, and yavannamire with its globed and scarlet fruits. Flower, leaf, and rind of those trees exuded sweet scents, and all that country was full of blended fragrance...only here grew the mighty golden tree malinorne, reaching after five centuries a height scarce less than it achieved in Eressea.

Perhaps an echo of what Fangorn, Mirkwood, etc. could have been without
the machinations of Morgoth and Sauron