No vacuum, we have grasslands - native to our area. They are taking over the grasslands.
Looks like they grow back faster and harder if you hurt them (cutting or weeding). But we are trying to weed them with the backhoe at the moment. You cannot do any of these by hand, they are growing back too aggressively.
Doesn't look like they are fazed by other trees either. They grew in and out of an existing wood in the area and took over around the existing trees.
They make nice fenceposts though.........