Cattle herding in Caspian forests

Reading the Wiki on the White Revolution in Iran and I came across this

“While the Caspian forests were nationalized, the forest inhabitants—primarily cattle herders—were expelled by the government and relocated to nearby villages”

How does cattle herding work in forests? Isn’t hard for herds to move around, and is there really sufficient grazing for them?

I’m not saying it’s not a thing, just that I’ve never heard of it and curious how it works.