The City shall have the right to plant, prune, maintain and remove trees, plants and shrubs within the right-of-way line of all City streets, alleys, avenues, lanes, squares and public grounds, as may be necessary to insure public safety or to preserve or enhance the symmetry and beauty of such public grounds. The Tree Board may remove or cause or order to be removed, from right-of-way, any tree or part hereof which is in an unsafe condition or which by reason of its nature is injurious to channels, sewers, electric power lines, gas lines, water lines, or other improvements, or is affected with any injurious fungus, insect or other pest.