What does the term diameter at breast height (DBH) refer to?

Diameter at breast height (DBH) is a standard forestry measurement that specifically refers to the diameter of a tree measured at approximately 4.5 feet (or about 1.3 meters) above the ground. This measurement is important for various reasons, including assessing the size and health of a tree, estimating timber volume, and facilitating comparisons among trees in a forest inventory.

The choice of 4.5 feet is practical, as it standardizes measurements across different tree species and growth forms while being above many ground-level irregularities that could impact accuracy. This height helps to provide a reliable indicator of the tree’s growth and is commonly used in forest management and ecological studies.