Peter Maish of Arborlink Consultancy has assessed privately owned trees for residents in the Ryde and North shore areas for the past 12 years. Trees can be assessed for a number of reasons however the two primary categories are tree health and structural integrity. A tree may appear to be healthy however its structural integrity could be weak.
Given the windy conditions in the Sydney area today, I thought it appropriate to breifly discuss wind induced tree failure caused by a combination of strong wind gusts and defective root systems. As many people would be aware wind is the primary cause of tree failure. A normal healthy tree can usually withstand strong winds (within reason) however trees with defective root systems are pre-disposed to failure during strong wind events.
Some of the causes of root system failure include termites fluting out the centre of structural roots, a containerized asymmetrical root system or the most common cause being root severence close to the tree during trenching or other forms of excavation during development works. One simple way of checking a tree's stability is during strong winds like today. If you look closely at the lower trunk of a tree at ground level and the trunk is moving from side to side (even slightly) your tree may be hazardous. Normal healthy trees with good root systems do not sway at ground level.
If your tree is moving at ground level it is worth having the tree assessed by an expert Arboriculturalist as soon as practicable. I will mention that the above check is to be observed where the trunk enters the soil. Bending moments will occur in the trunk and larger branches of trees during strong wind and bending is OK BUT ROCKING OF THE ENTIRE ABOVE-GROUND PARTS OF A TREE FROM GROUND LEVEL IS DEFINATELY CAUSE FOR CONCERN
Peter Maish
No comments:
Post a Comment