The terms of office of the present members of the State Commission of Forestry are hereby extended from the thirtieth day of May to the thirtieth day of June of the year in which their present terms expire. The successor to the member whose term expires hereunder on June 30, 1953 shall be appointed for a term of five years from that date, and the successors to the members whose terms expire on June 30, 1954, 1955 and 1956, respectively, shall be for a period of six years, and thereafter all appointive members shall be appointed for a term of six years. The president of Clemson University shall continue a member of the Commission as long as he retains his office as president of the University.