IT might come as no surprise to some that Jimboomba and North Maclean have some of the oldest – and biggest – trees in Logan.
North Maclean’s “Gandalf”, the name given to a tallowwood thought to be the city’s biggest tree, has some rivals but is yet to be overtaken.
The latest survey of trees in the city, carried out by qualified arborists, found a forest red gum (Eucalyptus tereticornis) in Jimboomba sits just behind Gandalf at 2.11m across, compared with the champion’s girth of 2.38m.
Arborists use a metric called diameter-at-breast-height to measure the width of trees.
The latest round of testing has also found some ancient species. The Jimboomba tree is thought to be 359 years old. Gandalf is 380.
A Eucalyptus carnea (thick-leaved mahogany) found at Priestdale in the latest round of testing is thought to be 270 years old.
Arborists used a resistograph to measure the ages of the trees.
Changes in speed of a micro drill bit inserted into the trunk are analysed, allowing experts to age the tree.
The survey was commissioned by Logan City Council and councillor Jon Raven said the specialist testing always turns up some grand old trees across the city.
“These ageing species have important roles to play in our environment. Branches breaking off over the years provide vital protection for native birds and wildlife.”
Local councillor for the Jimboomba region Scott Bannan said: “Jimboomba people are tough, and it looks like our trees are, too – they must be to grow this big and survive this long.
“The science behind the numbers is pretty cool.”
Council keeps a list of significant trees across the city. Residents who have trees they think fit the bill can email environment@logan.qld.gov.au or phone 3412 4491.
Pictured: Councillors Scott Bannan and Jon Raven take in the majesty of the newest giant of the forest at Jimboomba.
