Mass. Gen. Laws ch. 87 § 5
Tree wardens and their deputies, but no other person, may, without a hearing, trim, cut down or remove trees, less than one and one half inches in diameter one foot from the ground, and bushes, standing in public ways; and, if ordered by the mayor, selectmen, road commissioners or highway surveyor, shall trim or cut down trees and bushes, if the same shall be deemed to obstruct, endanger, hinder or incommode persons traveling thereon or to obstruct buildings being moved pursuant to the provisions of section eighteen of chapter eighty-five. Nothing contained in this chapter shall prevent the trimming, cutting or removal of any tree which endangers persons traveling on a highway, or the removal of any tree, if so ordered by the proper officers for the purpose of widening the highway and nothing herein contained shall interfere with the suppression of pests declared to be public nuisances by section eleven of chapter one hundred and thirty-two, including the Dutch elm disease.
Mass. Gen. Laws ch. 87, § 5