[cmrdporcupine]

In the northeast / midwest / great lakes basin, mastodons definitely helped clear underbrush, from what I've read. Not sure how common they were through the eastern woodlands, but they were definitely here (and likely hunted to extinction). You can see plants that have historical adaptation to their form of browsing; black locust (Robinia pseudoacacia) has spikes along its younger, more tender branches that don't effectively deter deer but would be nasty on a trunk, for example.

First nations here also did controlled burns to open cultivation for maize agriculture and to encourage open grazing areas for deer.

Regardless, the forests that are burning in this case causing smoke in the northeast are quite far north, in Northern Quebec mostly, in what is boreal forest; pine & spruce mainly, on thin granite soils (Canadian shield).