Quite a few places mention how Minhiriath's forests were felled by the Dunedain in the Second Age, and then how the entire region was depopulated (or almost so) after the Great Plague in TA 1636. Most, if not all, sites and books still make the claim that the region is deforested. Well, assuming the climate and hydrology hasn't changed, there's no reason why the great forests wouldn't re-grow. There's nobody there to cut them down, is there? The War of the Ring started in TA 3018. That's 1382 years of potential regrowth. More than mother Nature needs, trust me.
There'd be forests in Minhiriath again.