Tree diameter, height and stocking in even-aged forests

• 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 = β(H ‑ 1.3)/ ln(N).• Thinning causes a relatively small and temporary change in the slope β, 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. • 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 = β(H ‑ 1.3)/ ln(N). • Thinning causes a relatively small and temporary change in the slope β, 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.