Such sum of money when ascertained to be due as a tax by the filing of the foregoing statement and return, under oath, and, as hereinbefore provided, directed to be paid to the county treasurer by the owner of an auxiliary forest reserve, shall, from the time of such filing, be and remain a lien upon the land of such owner until payment shall have been made: And be it further provided, That all moneys received by the boards of supervisors shall be appropriated exclusively to the opening, maintenance, and repair of the public roads now or hereafter passing through or into said auxiliary forest reserves, or upon which said reserves now or hereafter may abut; and, in the event that no public highways pass through or into said reserves, or none of said reserves abut on such highways, then said moneys shall be used for general township road purposes.