Establishes base selection criteria for exceptional trees. Establishes the significant tree designation, selection criteria, and related processes. Establishes the State Arborist Advisory Committee within the Department of Land and Natural Resources for administrative purposes. Requires County Arborist Advisory Committees to have at least six members, adopt new exceptional tree selection criteria, and designate significant trees. Directs the Department of Land and Natural Resources and the University of Hawaii to cooperate with State and County Arborist Advisory Committees to carry out the Exceptional Trees Program.