Said Board shall consist of seven members who shall be appointed and serve in the following manner. The governing board of the Town of Livonia shall appoint four members of the Joint Planning Board, one member to be appointed for a one-year term, one member to be appointed for a three-year term, one member to be appointed for a five-year term and one member to be appointed for a seven-year term. The Mayor of the Village of Livonia, subject to the approval of the Board of Trustees of the Village of Livonia, shall appoint three members of the Joint Planning Board, one member to be appointed for a two-year term and one member to be appointed for a four-year term and one member to be appointed for a six-year term. Upon the expiration of the term of a member of the Joint Planning Board, that person or body which appointed the incumbent to the expiring term shall appoint his or her successor to a full seven-year term. If a vacancy occurs other than by expiration of a term of office, that person or body which appointed the member who filled such office prior to the vacancy occurring shall appoint a successor for the balance of the term.