Question

What does the variability in the DBH of individual trees tell you about the site it came from?

Answer 1

DBH is shorthand for the diameter of a tree’s trunk measured at breast height.

While there is some variation internationally, the standard method for measuring and reporting tree diameters is quite consistent.

In the U.S., DBH is the diameter of a tree stem measured at 4.5 feet above the ground.

In Canada, Europe, and most of the rest of the world, “metric DBH” is measured at 1.30 meters (4 feet, 3.2 inches).

In Japan and Korea, it’s 1.20 meters, and in New Zealand, it’s 1.40 meters

DBH is used in estimating the amount of timber volume in a single tree or stand of trees utilising the allometric correlation between stem diameter, tree height and timber volume.

It can also be used in the estimation of the age of veteran trees, given that diameter increment is the only "constant non-reversible feature of tree growth"