Ala. Code § 9-13-110
It is the intent of the Legislature that the forest products severance tax prescribed in subsections (a) and (b) of Section 9-13-82, beginning July 1, 2017, shall initially generate revenues not less than the revenues generated by the tax prior to July 1, 2017. In order to ensure that the revenues previously generated are not decreased, the department shall determine the total forest products severance tax revenue generated from all severance taxpayers from Act 2017-301 for the fiscal year ending September 30, 2018. The department, no later than December 1, 2018, or as soon thereafter as practical, shall determine the amount collected from all severance taxpayers for the fiscal year ending September 2018. If the forest products severance tax generated from all severance taxpayers in the fiscal year ending 2018 are less than the forest products severance taxes generated from all severance taxpayers in the fiscal year ending in 2017, on January 1, 2019, or as soon thereafter as practical, the department shall notify all severance taxpayers of the rate adjustment needed to maintain collections at the level received and collected by all severance taxpayers prior to July 1, 2017. The rate adjustment shall be effective no earlier than the quarter beginning April 1, 2019. The rate adjustment provided for in this section shall be a one-time adjustment to each of the tax rates set forth in Section 9-13-82, and no further adjustments shall be made pursuant to Act 2017-301.
Ala. Code § 9-13-110 (1975)