For those people who are responsible for the maintenance and management of public spaces in and around trees in Brisbane you should know that there is an easy way to have your significant trees assessed for health and risk. Sometimes the health of a tree and its structural stability can be overlooked. To the lay person what appears to be a satisfactory branch, union, or cavity may actually be hiding or signifying a more hazardous situation.
As we know, the weather plays a large role in the heath and structure of our plants. High wind can dislodge limbs and branches, some may completely detach, where some may become entangled within the canopy and stay up there for years. Wind can also create certain stresses on parts of trees that will only be exposed after the actual wind event is over.
Consistent and heavy rainfall may cause a tree to put on rapid excessive growth which may lead to over laden limbs, leading to failures due to weighted canopies. Heavy rainfall combined with strong winds may cause ‘root heave’ a situation in which the tree has been pushed upon by the wind like a lever and the ground amongst the root system has lost its integrity; This then means the roots can begin to slip and lift under the pressure of the tree’s movements in the wind. While the trees canopy may seem healthy, a significant reduction in tree stability has occurred and may not be easily recognisable.
Hot dry spells of little to no rainfall can case ‘Sudden Limb Drop’, a phenomena where mature plants of no discerning structural issue will eject a limb from its canopy. Usually a large limb with no warning will fail, usually catching those nearby off guard. This scenario is obviously a severe hazard and potentially fatal.
Human interaction is generally the most likely cause of poor plant health and structural failure. By employing low standard contractors to preform non-compliant tree works, you will damage your trees and leave yourself liable in the case property damage or loss of life, if or when tree failure occurs. Excavation/trenching and the depositing of fill around trees are also harmful actions and will significantly reduce a tree’s health and stability. Also by constructing poorly thought-out hard landscapes and structures, a tree’s root system will be heavily impacted upon. These factors and more are all human made decisions, usually omitting the need to manage trees and their surroundings with appropriate consideration and acknowledgment of human’s impact upon them.
Having said that, those of you who live in Brisbane will know that we have a good relationship with our urban forests and we are generally good stewards. However neglect or ignorance is no excuses in the aftermath of catastrophic failure and so pre-emptive action will need to be taken in lieu of such events.
An Arborist or tree manager is a formally trained contractor who can determine potential aerial hazards and deduce a way of managing them so as to reduce the chance of failure. Obviously it would be unreasonable to suggest a complete elimination of the aerial hazard, however an accurate Tree Risk Assessment or Tree Audit on your own personal property or perhaps one you manage or work at can be the best way to mitigate risk and improve peace of mind.
A ‘Tree Audit’ will be conducted many ways, firstly those trees of significance will be selected and assessed and sometimes a climbing arborist will be required to investigate the upper canopy. This is a thorough investigation and will provide comprehensive overall assessment. Once the evidence is compiled then a management strategy can be put in place. This may involve pruning works compliant to the Australian Standard 4373 or perhaps the complete removal of some high risk trees. Some trees may need more assistance and soil reparations may also be required or even the implementation of a cordoned off area allowing for root recovery.
Either way the result of the Tree Audit will give you usable and accurate strategy to help assess risk potential, manage tree health and plan future development and infrastructure.
So if you are curious about a Tree Risk Assessment or a Tree Audit, contact a certified Arborist, ask for his credentials, accept nothing less than a Level 5 arborist with at least ten years industry experience and genuine passion for trees. Make sure they are also fully insured.
The Tree Audit Brisbane.