The value of any deciduous trees, shrubs, plants or crops, whether annual or perennial, and any cultured Christmas trees, as defined in ORS 215.203, or timber described under ORS 321.267(3) or 321.824(3), growing upon agricultural land devoted to agricultural purposes, shall be exempt from assessment and taxation and shall not be deemed real property under the provisions of ORS 307.010.
ORS 307.320