In counties with less than 3,000,000 inhabitants, any land being managed under a forestry management plan accepted by the Department of Natural Resources under the Illinois Forestry Development Act shall be considered as "other farmland" and shall be valued at 1/6 of its productivity index equalized assessed value as cropland. In counties with more than 3,000,000 inhabitants, any land totalling 15 acres or less for which an approved forestry management plan was in effect on or before December 31, 1985, shall be considered "other farmland". The Department of Natural Resources shall inform the Department and each chief county assessment officer of each parcel of land covered by an approved forestry management plan.
35 ILCS 200/10-150