Legal Question in Mediation in New Jersey

It is very unlikely, although not impossible that the tree is "on the property line". You should have a survey of the property which would demonstrate on whose property the tree is located. The fact that there is an overhang onto one property from another does not make it on both properties. Generally speaking, although the law may be peculiar in your state, the person who owns the property where the the tree is located would be responsbiel for any cleanup. As neighbors you do not want a war. However, if you feel it necessary and the neighbor will not be reasonable this is a perfect matter for small claims court. Make sure to have your proofs assembled, not just your "say so". Good luck.