Ecological Thinning Trial set to commence

Media release: 28 February 2016

The trial of ecological thinning in the Murray Valley National Park is set to commence in March after being given the green light by the Commonwealth Department of Environment.

NSW National Parks and Wildlife Service Head Michael Wright said the trial was based on scientific principles.

"The aim of the trial is to test whether thinning improves the ecological health of the red gum forest and also to improve our knowledge of the best way to manage conservation outcomes in these forests," Mr Wright said.

"Ecological thinning involves the selective removal of trees to reduce forest density, with the aim of improving forest health. It is based on the scientific concern that some areas of river red gum forest may have an "unnaturally" high density of trees due to altered flooding regimes, and that this is impacting on their ecological values.

"The object of this trial is to measure the impact of ecological thinning on key forest health indicators such as biodiversity, habitat and canopy condition. By comparing the values between thinned and un-thinned sites over time, we will be able to determine whether thinning can deliver beneficial impacts.

"Recommended by the Natural Resources Commission (NRC) in December 2009, the trial has been reviewed by an expert panel of scientists and has now been determined by the Commonwealth as not impacting on matters of national significance under the Environment Protection and Biodiversity Conservation Act."

The trial and associated monitoring program has been developed and reviewed by scientists and an independent biometrician.

"This was the final stage in approval of the trial, which is now set to begin," Mr Wright said.

"The ecological thinning work will be carried out by local Moama contractor Barberosa Pty Ltd, who was the successful tenderer following an open procurement process.

"Thinning will be undertaken at 44, nine hectare plots in Murray Valley National Park at Millewa in NSW. A total of 396 hectares will be thinned, which accounts for around 0.9% of the total extent of River Red Gum forests and woodlands within the Millewa Group of Murray Valley National Park.

"Safe guards are in place to ensure protection of the park during the trial. Known threatened species, large trees and hollow-bearing trees will be protected through careful selection of sites and trees.

"Trees will be thinned from defined plots and will not involve clear felling. Subject to good weather, the thinning works should be completed over a nine week period while the research component of the work will run over five years.

Detailed scientific monitoring will occur over the next five years as detailed in the Experimental Design and Monitoring Plan. After five years, a review of this plan will occur to determine the effectiveness of this monitoring and to assist in planning future monitoring needs.

"The aim is to address key gaps in knowledge about how to manage river red gum trees for maximum forest health," Mr Wright said.

Contact: Gabrielle Last