All income which may be received from lands acquired by the state heretofore or hereafter for state forest purposes by gift, purchase or eminent domain and tax-forfeited lands to which the county has relinquished its equity to the state for state forest purposes shall be paid into the state treasury and credited as provided in this section, except where the conveyance to and acceptance by the state of lands for state forest purposes provides for other disposition of receipts. The income derived from timber sales receipts shall be credited to the forest management investment account and the amounts derived from all other receipts shall be credited to the general fund.