Upon withdrawal of said lands or any part thereof as auxiliary state forests or harvesting or other use of parts of timber on said land without withdrawing the land, the value of the timber thereon shall be appraised separately in each county where such timber is located by the Department of Revenue and the State Forestry Commission as of the date of such withdrawal or harvesting, whereupon the owner of such timber shall pay as a privilege tax for the entry and withdrawal of such lands as auxiliary state forests or for the harvesting of the timber on such lands a sum of money equal to eight percent of the appraised value of the timber.