Land reserved for open space shall, in the judgment of the Planning Board, be of a character and location suitable for whatever open space purposes the land shall primarily be reserved for, such as natural areas, wildlife preserves, conservation areas, outdoor recreation sites, neighborhood parks, nature centers, wetlands, memorial forests, natural watercourses or other open space uses. The Planning Board may require that the open space be located at a suitable place on the edge of the subdivision so that additional land may be added at such time as the adjacent land is subdivided. Reserved open space shall not be narrower than 200 feet, except where necessary to provide a pathway or other means of access. An easement for a natural watercourse dedicated to the Town may be considered as open space for the purpose of this regulation if such easement is at least 200 feet wide.