No person shall, without the written permission of the director of public services, place or maintain upon the grounds within the lines of any street, parkway or other public place within the village, stone, cement or other substance which shall impede the free passage of air to the roots of any tree located within the lines of such street, parkway or other public place, without leaving an open space of ground outside of the trunk of such tree in an area not less than four feet (4') square. (Ord. O2011-08, 2-15-2011)