(b) If the director of the division of forestry has reason to believe that managed timberland was or is being converted to a use that disqualifies the property from treatment as managed timberland, the director shall investigate. If, upon investigation, the director determines that the property no longer qualifies for treatment as managed timberland, the director shall revoke the property's certification as managed timberland. The director shall give written notice to the owner of the property by certified mail, return receipt requested, to the tax commissioner and to the assessor of the county in which the property is located that the property no longer qualifies for valuation as managed timberland. If the property is located in two or more counties, notice shall be given to each assessor.
(c) If any person fails to give written notice of the change in use of managed timberland as required in subsection (a) of this section, the person owning the property shall be subject to a penalty in an amount equal to the amount of additional taxes the person would have paid on the property if written notice had been timely given, plus interest calculated at the rate of nine percent per annum: Provided, That the maximum penalty under this section shall be five years of additional taxes plus interest. This penalty may be assessed in the same manner as back taxes are assessed under section five of this article for omitted property and interest shall accrue until the day the penalty is paid.
(d) This section shall apply to tax years beginning on or after the first day of January, one thousand nine hundred ninety-nine, and to changes in use occurring on or after that day.