The revision was carried out following research funded by Hort Innovation using nursery industry levies and funds from the Australian Government, which found the current specified range of size index did not adequately capture the natural variation across the large diversity of trees grown in Australian nurseries.
The aim of the project was to assess the standard, most notably the root to shoot balance concept, and consider the performance of trees across a variety of climates, species, container sizes and nursery practices, to provide certainty of quality for the purchaser.
The Standards Australia Arboriculture Committee, which brings together representatives from the nursery, arboriculture, landscape architecture, parks and gardens sectors, as well as local governments and universities and Hort Innovation, considered the data and used it to inform improvements to the current standard.
The most significant change to the standard is based on the tree stock balance appendices (D & E) which have been replaced by a single appendix that depicts the Western Sydney University data in graphs and tables, and segments this data into broad ranges. It is presented in an easy-to-use format, and enables growers and specifiers to compare their trees to a real-world population of tree stock.
The next step is public consultation, which will run until 6 August 2018.
Nursery and Garden Industry Australia (NGIA) CEO Peter Vaughan said the proposed revision of the tree standard considers a diverse range of opinions and needs across the supply chain.
"The tree standard is widely used by local councils, developers and landscape architects as a decision-making tool to determine whether a landscape tree is fit for purpose,” Mr Vaughan said.
“The revelation that the current standard imposes limits that are too narrow, means that landscape trees are being potentially rejected by the standard when in fact they are of acceptable quality.
“The Western Sydney University work provides a scientifically validated base to inform a revised standard that encompasses a more accurate and representative measure of what trees in Australian nurseries look like to broaden acceptability and saleability of more trees.
“It’s great to see such quality research conducted on behalf of the nursery industry from one of Australia’s leading universities, and I’d like to thank the team for their valuable contribution to our collective knowledge.”
Mr Vaughan said that industry’s ongoing support for urban greening reiterated the need for a consistent tree standard, to ensure trees lived a longer, more productive life once they left the nursery and were planted into the Australian landscape.
“We’re following through with our commitment to ensure a standard is fit for purpose and widely accepted by growers and, more broadly, end users such as councils and developers,” he said.
“I encourage growers to review the proposed revision of the standard, to arm themselves with the latest information and, importantly, provide their feedback.”
To review the draft revision to the standard, visit: https://hub.standards.org.au/hub/public/listOpenCommentingPublication.action