California Code, Revenue and Taxation Code - RTC § 38116

(a) Subject to the limitation in subdivision (b), there is exempted from the tax imposed by this part timber whose immediate harvest value is so low that, if not exempt, the tax on the timber would amount to less than the cost of administering and collecting the tax, as determined by the board by rule. The board, after consultation with the Timber Advisory Committee, shall establish by rule the level at which the tax that would apply is less than the cost to administer and collect the tax.

(b) The board shall have no authority to exempt timber with an estimated immediate harvest value of more than three thousand dollars ($3,000).