stamdiameter

Stamdiameter is the diameter of a tree trunk measured at a standardized height above the ground. In forestry, the common reference height is breast height, traditionally 1.3 meters above the soil, and the measurement is usually reported in centimeters. Some protocols use alternative heights, such as 1.0 meter or 1.2 meters, particularly for younger trees or non-standard stems. Stamdiameter is a basic size metric used to characterize individual trees and to compare trees within a stand.

Measurement is typically performed with a diameter tape or calipers. If a circumference is measured, the diameter is obtained by dividing the circumference by pi. For straight trunks, the measurement is taken at the chosen height, avoiding irregularities in bark or deviations from a perfect trunk. For trees with buttressed bases, some protocols specify measuring above the buttress or at a defined height on the straight trunk. In irregularly shaped trees, multiple measurements may be averaged or adjusted using standard allometric methods.

Stamdiameter serves as a foundational input for estimating basal area, wood volume, biomass, and carbon stocks through allometric equations. It underpins routine forest inventories, growth models, and timber assessments. Precision depends on consistent height, appropriate equipment, and careful handling of trunk shape and measurement challenges. While DBH at 1.3 meters is widely used, some studies adapt the measurement height to suit species, age, or local protocol.