Introduction:

Both public and scientific interest of trees have increased in recent years. From a public viewpoint, although rare, tree failure causing catastrophic damage or injury often attracts a disproportionate volume of media attention. Pictures of large trees laying on the ground between two halves of a once intact family home elicit a fear response of residents living in a close-proximity to parklands, bushland reserves or just a large growing species of street tree.

“Is the tree next to my home safe?”

“How can I possibly know?”

“I had better request that the council cut it down just in case!”

Running parallel to public discourse on the matter of tree safety is a growing body of research showing that trees in the urban environment are critical to the environmental function of cities around the world. Amelioration of the urban heat island effect (EPA 2018), carbon sequestration (UNWIN & KRIEDEMANN 2000), control of rainwater runoff (ASADIAN & WEILER 2009) and the fostering of biodiversity (ALVEY 2006) are among some of the benefits associated with adopting a robust urban forest program.

Despite this, the urban forest in under threat from a myriad of abiotic pressures in most of the world’s urban centers. Coupled with this is the increasingly litigious nature of urban tree management. Rather than recognising the vast environmental benefits of growing the urban forest in relation to the often-low level of human fatality and property damage (HELLIS 2018), trees are often culled unnecessarily due to a heightened, irrational fear that a tree will fail unpredictably and adversely affect the tree owner.

At the nexus of the public perception of tree risk and urbantree management sits the (not always) humble arborist. Charged with assessing tree risk, when armed with experience, knowledge and the correct diagnostic tools, he or she can both safeguard against unnecessary tree removal in the urban environment and correctly identify trees which require immediate removal.  

To affectively achieve this, the arborist must be free from professional bias and not harness an irrational fear of trees — additionally, knowledge of tree morphology, physiology and function as well as the symbiotic and parasitic organisms which may affect the trees heath, structure, or both.

The purpose of this website is to examine the degradation of the structure of a tree as it ages and becomes host to decay-causing organisms. Furthermore, how disfunction in a trees structure is managed will also be explored as well as the methods of detecting structural defects.

As you will discover, much is known about how to detect structural defects. Less is known about the parameters at which a tree should be managed or removed.