Life Belt – Bulging Wood

You may have come across a tree which has the following distinct characteristic and wonder what was going on:


  • The tree has what could be described as a distinct bulge around its girth like a belt. This defect can also be noted around the stem base.

This could be a sign of:

  • Localized wood failure otherwise known as Fibre Buckling.

What is Fibre Buckling?

  • This is where the internal wood is failing under compression, due to the wood becoming decayed.


It is debatable as to the representable hazard such a defect poses, especially with conifers that have this defect.


Although the significance of this kind of defect is debatable, It does however indicate the presence of internal wood decay. Therefore such a defect should not be dismissed out of hand. The following action is recommended:

1 Visual checks of the whole tree from ground level looking for any significant defects, should be carried out when the tree is in leaf, and during the fungi season (autumn)

2 Any other defects which are noted should be further investigated (if required) and a management programme actioned accordingly.