The general treasurer is hereby directed, authorized, and empowered, with the approval of the governor, to receive, take title to, and hold in trust for the state, exempt from taxation, any gift, grant, or devise, of lands or interests, estates or rights therein, and any gift or bequest of money or other personal property, made for the purposes of this chapter, subject to the approval of the director of environmental management; and unless otherwise provided by the terms of any gift or bequest of money or other personal property, the general treasurer shall preserve and invest that money or the proceeds of that other personal property in notes and bonds secured by good and sufficient mortgage security, or in such securities as by law the sinking fund commission is authorized to invest. The trust property and real estate shall be known as the metropolitan park trust fund and shall be used under the direction of the department of environmental management, subject to the orders of the director of the department, under the terms of such trusts as may be provided by the donors thereof.