The Governor shall request and the General Assembly may annually appropriate from the Natural Heritage Fund an amount not to exceed the annual investment income earned by the Trust Fund to the Department and any portion of the investment income earned in preceding years that was not transferred for the purposes set forth in Section 4. Upon the Director’s request, the Comptroller and the State Treasurer shall transfer amounts not to exceed the actual investment income earned from the Trust Fund to the Natural Heritage Fund from time to time as needed for expenditures from the Natural Heritage Fund in accordance with appropriations.