Nitrogen fixing shrubs/small trees native to NE?
I'm trying to find a list of good nitrogen fixers for my sorta-forest garden plans, to go to work on my starved lawn and improve the soil. Had all kinds of plans involving autumn olive, etc., until I found it seems to be banned in NY. Then, many other popular nitrogen fixers are really Wester/great plains plants, and I don't want to try to coax them into survival here, that's not really the point.
So, so far, I've found ... sweet fern. Any other mostly-native suggestions?