Some of that land historically was inhabited by relatives of current herbivores (bisons) so some of the land is feeding herbivores as it did historically.
Now, there are places where forest was cut down for grazing. Thats true. We also have experience where leaving the land alone a few decades reverts it back to forest (this is seen in forests in the eastern US which were once grazing lands for domesticated herbivores and now are back to being mature forests.
Now, there are places where forest was cut down for grazing. Thats true. We also have experience where leaving the land alone a few decades reverts it back to forest (this is seen in forests in the eastern US which were once grazing lands for domesticated herbivores and now are back to being mature forests.