Too much Neighborhood Decor

[Avalikia]

Is there some way to remove all the decorations from a currently played neighborhood other than grabbing and deleting them individually?  I recently downloaded some very good neighborhood templates - very good except that they're being invaded by so many trees that my computer can't handle them very well at all and it would take literally hours to delete enough to solve the problem.  If I can't do this with my already played neighborhoods, is there a way to cleanse the neighborhood template?