I am quilty of being unaware and planting some of these invasive plants/ trees.  I appreciate you raising the issue and educating us.  I just returned from a Wisconsin visit and noticed sparse and random patches of fireweed.  It looked the same as our beautiful fireweed, but rare patches.  I questioned others why it wasn't everywhere and as amazing as we have here.  Lots of different opinions where thrown out about farm pesticides killing them off, etc., but never invasive species pushing them out.  I do not know the reason, but I am seeing a purple flower looking "weed" ground cover spreading in places here I've never seen before.  It would be sad if our amazing fireweed became a rare sight, not to mention all the other things we take for granted like moose and salmon.  Again, I appreciate you educating us all.