The Environmental and Technical Manager for NGIA, Dr Anthony Kachenko, reports that Standards Australia has agreed to commit resources to progress the Standard over the next two years.
“The proposed Standard concerns trees that are grown in commercial nurseries and supplied for general use in landscape situations. Trees that are poorly grown are considered as one of the most common causes for tree failures,” said Anthony.
“The Australian Standard for Specifying Trees will detail some prescribed requirements for growers and their customers such as councils, developers, landscape architects and contractors to comply with.”
“We see this as an opportunity to increase the output of quality product grown by industry that complies with the Standard, as well as providing these growers with a competitive advantage,” added Anthony.
The bulk of the problems associated with tree failures occur under the ground in the root system. Girdled and kinked root systems limit the ability of the tree to take up water and nutrients and may provide inadequate support.
Stems with inadequate taper cannot support themselves and encourage the use of artificial supports such as stakes and ties, while tall plants in undersized containers generally have insufficient root volume to support them both biologically and physically.
“Improving the quality of trees at planting time will result in less risk of trees falling in extreme weather events and will ensure a more robust life for our urban forests, which are becoming increasingly important in public policy to ensure healthier environments and hence healthier populations in our cities,” said Anthony.
“There is also an economic benefit as significant costs in replacing failed trees will be avoided.”
NGIA has consulted with key growers and several stakeholders in local government, research organisations and other professional associations such as the Australian Institutes of Horticulture and Landscape Architects and Aboriculture Australia in developing the proposed Standard.
“Currently we only have the NATSPEC-Specifying Trees guide which is good but only voluntary. An Australian Standard will incorporate key aspects of the NATSPEC guide and provide industry with a unified and national reference for all growers to consider.”
The proposed standard will define a tree as a long-lived woody perennial plant greater or potentially greater than three metres in height with one or relatively few stems. It will exclude shrubs, palms or trees that are produced for topiary.
“We are now asking for growers across Australia to have their say and to register their interest to receive progress updates. In 2012 our industry’s theme is ‘More Trees Please’ to improve our plant/life balance – more quality trees will be even better for healthy urban forests in our cities,” added Anthony.