Oregon Revised Statutes Revenue and Taxation § 321.366

(1) Notwithstanding ORS 308.210, 311.405 or 311.410, but subject to subsection (2) of this section, the removal under ORS 321.359 (1)(b)(C) of land from designation as forestland because the land is no longer forestland shall occur as of the January 1 assessment date for the tax year in which the county assessor discovers that the land is no longer forestland.

(2) Subsection (1) of this section applies only if notice of the removal is mailed by the county assessor prior to August 15 of the tax year for which the removal of the land is asserted.