i think it has been proven that they are not a threat like chinese privet. maybe this research was done in the period where there werent hardly any deer in alabama. i dont know when that was because i was not around then.but if that is the period when this research was done, and there were not animals eating all the acorns the sawtooths were putting out every year and the acorns were all left to sprout, then with the short time to maturity for these trees and the abundant seeds(acorns) that come from them on a yearly basis unlike other oaks that will have a bumper crop maybe every 5 years then yes i would see where they could be rather invasive and prolific. but in these times with as high of a deer population as we have i dont ever see a single sawtooth acorn left to sprout.