2006 New York Code - Protection Of Trees.

 
    §  27-1030 Protection of trees. No trees outside the street line shall
  be disturbed or removed without the permission of  the  commissioner  of
  parks  and  recreation.  Protection  meeting  the  requirements  of  the
  department of parks and recreation shall be provided around  the  trunks
  of  all  such  trees, and written notification shall also be made to the
  department of parks and recreation at least forty-eight hours  prior  to
  commencement  of  such  work.  No deleterious, caustic, or acid material
  shall be dumped or mixed within ten feet of any  such  tree,  nor  shall
  salt for the removal of ice or snow be applied when runoff will drain to
  a tree.