Tree diameter, height and stocking in even-aged forests

TL;DR

This paper presents an empirical relationship linking tree diameter, height, and stand density in even-aged forests, offering a simple predictive model useful when data is limited.

Contribution

It introduces a practical formula relating diameter, height, and density in pure even-aged forests, useful for growth prediction with scarce data.

Findings

Diameter remains proportional to stand height divided by log of density.

Thinning causes small, temporary changes in the proportionality slope.

The relationship is robust across different thinning scenarios.

Abstract

Empirical observations suggest that in pure even-aged forests, the mean diameter of forest trees (D, diameter at breast height, 1.3 m above ground) tends to remain a constant proportion of stand height (H, average height of the largest trees in a stand) divided by the logarithm of stand density (N, number of trees per hectare): D = beta (H-1.3)/Ln(N). Thinning causes a relatively small and temporary change in the slope beta, the magnitude and duration of which depends on the nature of the thinning. This relationship may provide a robust predictor of growth in situations where scarce data and resources preclude more sophisticated modelling approaches.