TheKeith wrote:

I live in Brooklyn, NY and in the backyard is a 30-yr old maple tree that my
parents planted before I was even born. The tree was planted about 2 feet
away from the fence and now, 30 yrs later, is a bit of a monster--part of
the trunk is on my neighbors side. They are currently putting up a big fence
and have already managed to convince my parents to let them cut a chunk away
from the very bottom of the trunk (my parents consulted a tree surgeon first
of course, and he said it was ok)--now the neighbors are saying that they
need to cut what appears to be a major root (almost looks like part of the
trunk itself)--the tree surgeon is coming over again tomorrow, but I'm
fairly certain that this is a vital component to the survival of the tree.
My grandfather was a real estate attorney and some years before he died
looked up some law regarding trees and discovered something called "air
rights" or something like that, which basically provided that the branches
of a tree, as long as it doesn't physically touch a neighbors property may
not be cut by that neighbor even if it is "over" their property. I was
wondering if there are any comparable laws regarding the tree trunk itself
and its major roots, which obviously run well under my neighbors property?
Help would be greatly appreciated -- thanks.

Explain the possible long-term consequences of cutting the roots vs. letting
them be. If the tree is located south to west of their house, it's very
possibly saving them hundreds of dollars in air conditioning costs. Loss
of the tree from an excessively hard root pruning could be counterproductive.

Even more so if the tree loses anchorage from a weakened root system...