How to measure DBH (diameter at breast height)

DBH is diameter at breast height: the diameter of a tree trunk measured 1.3 m above the ground. Asset surveys use it to class trees by size.

1. Stand on the uphill side of the tree and mark the trunk 1.3 m above the ground.
2. Wrap a tape around the trunk at the mark, level and snug, and read the circumference.
3. Divide the circumference by 3.14 to get the diameter. A diameter tape gives it directly.
4. If the trunk forks below 1.3 m, measure each stem as a separate tree. If there is a swelling or buttress at 1.3 m, measure just above it.
5. Record the species, DBH and owner on the survey form, and photograph the tree.

Some guidelines use 1.37 m. Use the height stated in the project's survey method, and use the same one for every tree.