The Safety-Service Director shall supervise the improvement, condition and repair of all streets, alleys, avenues, lands, lanes, squares and public grounds in the Municipality, and shall have the right to plant, trim, preserve and remove all trees within the lines of such streets, alleys, avenues, lands, lanes, squares and public grounds as may be necessary to insure safety, or to preserve the trees to the symmetry and beauty of public places. The Director may cause any tree which is in an unsafe condition or which by reason of its nature is injurious to sewers or other improvements, or is affected by any injurious scale or pests to be removed.