With the exception of oxygen (where a forest is definitely not a closed system, since the light from the sin and the co2 we breathe go back to the forest), the

With the exception of oxygen (where a forest is definitely not a closed system, since the light from the sin and the co2 we breathe go back to the forest), the amount that we remove from forests through foraging and hunting is trivial compared to the amount of resources we demand from agricultural land. And when we continually harvest wood, well, forests don't do well. Managed forests are basically just farms. Nutrient cycles are pretty slow - as we remove minerals amd nutrients from a forest (and dump those nutrients into oceans via sewage) - we are depleting forests. Forests can't produce excess minerals.