More Information
6.5 Measurement of Trees
Authors: E G MasonPublication: NZIF Forestry Handbook, Volume Section 6 – Data collection and projection, pp 5, Dec 2023
Publisher: New Zealand Institute of Forestry
Abstract: Tree measurement can include simple stem diameter and height measurements, measurements of stem defects, measurements of upper stem diameters, bark thickness, and/or whole tree biomass assessment to provide a basis for carbon accounting. SIMPLE STEM MEASUREMENTS Diameter The most commonly measured tree variable is diameter at breast height outside bark, usually abbreviated as dbh or more precisely as dbhob. Breast height is defined as 1.4 m above the highest ground point immediately adjacent to a tree stem unless this point is a branch whorl, in which case measurements can be made above and below the whorl and averaged, or a point close to 1.4 m that is permanently marked for later re-measurement. These measurements are often converted to basal area, which is the cross-sectional area in m² of the stem at 1.4 m. The formula for conversion of dbh to basal area (g) is: g = pdbhob²/40000