Or. Admin. R. 808-002-0881
"Trees" as used in ORS 671.520(1), ORS 671.690(3)(d) and OAR Chapter 808:¶
(1) For the purpose of pruning, a tree is defined as a woody plant usually having a dominant trunk, or trunks, with a diameter of 4 inches at a point 4.5 feet above the ground and a height greater than 15 feet (4.5 meters) at the time of pruning.
(2) For the purpose of planting, a tree is defined as a woody plant usually having a dominant trunk, or trunks, and a mature height greater than 15 feet (4.5 meters), and which generally has few or no branches on its lower part, and is crowned with a head of branches and foliage or, as in palms, of foliage only. Tree planting excludes the following:
ORS 671.670 & ORS 671.310
ORS 671.520 & ORS 671.690