Any person, firm or corporation violating or failing to comply with any of the provisions of this chapter shall be guilty of a misdemeanor, and upon conviction thereof, shall be fined a sum not to exceed one thousand dollars, or may be imprisoned for a term not to exceed ninety days, or both; provided, however, that in all events restitution shall be ordered commensurate with the value of the damaged or destroyed public trees or shrubs; and further provided that, any sentence requiring community service shall require not fewer than twenty-five hours of such service, to be supervised by the tree committee overseen by the city superintendent.