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New tree guard research a boost for successful revegetation

New research has demonstrated that using tree guards is an effective way to ensure newly planted revegetation projects survive the cold winters of the Northern Tablelands.

"One of the main barriers to the success of revegetation projects in this area is the winter climate," explained University of New England PhD researcher Sharon Brown.

Sharon's research is part of the Local Land Services (LLS) Brigalow Nandewar Biolinks project, supported by the Australian Government's Biodiversity Fund.

The Biolinks Project is providing research and support to encourage private landholders to enhance and increase natural vegetation, and to capitalise on the production benefits of natural biodiversity on-farm.

"Seedlings are fragile and struggle to survive and thrive in low temperatures and severe frosts," said Sharon Brown.

"The stress from exposure to cold limits the growth of eucalypts on the Northern Tablelands, which can result in poor survival and growth rates."

Sharon's research trials on 'Lakeview' at Uralla have found that tree guards are one of the most effective tools for reducing that cold stress. Different types of tree guards were compared.

The trial results so far show that the performance of seedlings of five native species (Leptospermum polygalifolium, Callistemon pungens, Eucalypts viminalis, E. acaciiformis and E. stellulata) was significantly better in 600 mm tall semi-transparent corflute tree guards, compared to seedlings planted in milk cartons, regardless of their position on sloping sites.   

The seedlings were monitored between March and November 2014 and the results showed that eucalypts grew 3.5 times higher in tall guards compared to milk cartons. At the lower sites all species grew better in tall guards compared to milk cartons, while at the mid and upper sites, four of the five species had better growth rates in the tall guards. 

"The use of tall tree guards helps to shelter the seedlings against cold induced damage, substantially improving performance," said Sharon.

Sharon's research has also highlighted the importance of matching cold tolerant species to cold environments.

"This has important implications for the management of eucalypt plantings in regions where extreme winter temperatures and severe frosts predominate, and highlights the need for further cold tolerance trials in eucalypts," said Sharon.

With many farmers and land managers currently preparing sites for spring plantings, the Northern Tablelands Local Land Services Project Officer, Martin Dillon, says landholders would be wise to plan ahead and carefully choose tree guards to ensure their seedlings survive next winter.

"A lot of money and hard work goes into new planting sites, so it makes sense to use tree guards so that their efforts aren't wasted when the next big frost hits," said Martin. 

"Landholders are increasingly aware of the agricultural benefits and shade and shelter provided by natural vegetation. However they're often discouraged by the high costs of revegetation and the potential for poor success. Although tree guards can add to the expense, the success rates are higher and results are seen sooner."

"The Brigalow Nandewar Biolinks project is investigating how to make large scale revegetation projects more economically viable.  The work of researchers like Sharon Brown is providing landholders with practical, evidence backed information to help their revegetation sites survive and thrive, even in our cold Northern Tablelands winters," said Martin.

For more information about suppliers of corflute tree guards, or about how you could be involved in tree planting as part of the Brigalow Nandewar Biolinks project, contact:

Martin Dillon on or phone 02 6770 2000.