But why would you do that? Don't cut down forests for soy, and don't cut it down for pasture either. Use existing green grass fields to feed cattle. This can be done in between crop rotations.
> without a serious decrease in worldwide meat consumption
Maybe that's the point?
Eat less (if you want to eat at all) and eat grass-fed. Do cattle even choose to eat soy when they have green grass available?
Eating less meat was the point from the start as the main/only way to decrease soy footprint, so if you're not suggesting to replace soy feed with grass then this whole discussion was in the end more or less pointless.
Monocrops are terrible for the planet & wildlife, and are only even viable due to heavy use of pesticides & NPK fertliser.
Organic farming requires large amounts of animal manure to work, guess where it comes from?
Please go read about regenerative agriculture - that's the way forward.
Europe is varied, not sure where you live but the forests in Northern/North-Central Europe that I'm familiar with absolutely do support wildlife. I think it shouldn't be controversial that returning agricultural land to nature, whatever "nature" means in different areas, is good for environment.
Anyway, this is wildly beside the point, which is that pasture feeding cattle can't satisfy the current demand for meat, not even close. Converting soy fields to grazing fields would be an ecological disaster without a serious decrease in worldwide meat consumption, as the yields would be far lower.