Stem diameter was recorded at 2m intervals up the stem. The North-South and East-West diameters were averaged, and this diameter was used in a fourth order polynomial to estimate stem diameter at intermediate heights. Data were "normalised" to allow comparison of trees of different diameters. The following graph is based on the average diameters of the calculated stem profile of each damage type.

The snapped trees are thinner at about 30% of tree height than either the standing or the overturned trees, although this difference is not quite statistically significant (p=0.10).

This initially looked as though it might explain the damage. However, when the stem density is investigated, then the causes of damage become less certain.