Last week on Channel 9’s Sunday Program, Reece Turner from The Wilderness Society stated: “We haven’t seen any scientific evidence to show that biodiversity is being impacted negatively by these woody weeds.”
Sunday reporter Ross Coulthart then asked Turner, “Do you accept that there are woody weed areas causing major environmental damage?” Turner’s response to the question was: “No. We don’t accept there are major environmental damages being caused by woody weeds.”
Mr Doug Menzies, in a media release from NSW Regional Community Survival Group, said that The Wilderness Society needs to drop its emotive rhetoric on land clearing in western NSW and urgently review the scientific literature on how infestations of woody weeds degrade the landscape.
The media release continued:
“The Channel 9 footage showing vast tracts of land degraded by woody weeds clearly showed how little understanding Reece Turner has on this issue. Turner needs to get off his bum and make the effort to review the scientific literature that details the negative environmental impacts of woody weeds,” Mr Menzies said.
Below are just some of the published scientific journals and reports that confirm the destructive impact of infestations of woody weeds on the environment:
Report of the Inter-Departmental Committee on Scrub and Timber Regrowth in the Cobar-Byrock district and other areas of the Western Division, NSW. February 1969.
“The density of timber and scrub regrowth on level loamy soils, which would normally run little water, is such that the small open spaces between clumps are completely bare and becoming wind sheeted and water sheeted. This class of country thus becomes a mosaic of bare, wind and water sheeted patches on which nothing can grow, interspersed with small clumps of thick scrub.”Alchin, B.M., Proude, C.K., and Condon, R.W. (1979). Control of Woody Weeds in Western NSW. Proceedings of the 7th Asian-Pacific Weed Science Conference.
“Regrowth of woody weeds is a major problem over millions of hectares on the rangelands of western NSW. The regrowth reduces pasture growth, increases management costs and results in soil erosion.”Control of Woody Weeds. Woody Weeds Taskforce. Information Sheet 5. September 1990.
“Woody weeds are native shrubs which have encroached formerly open lands of western NSW. The encroachment has lowered pastoral productivity, reduced botanical and faunal diversity, reduced land values and increased the risk of water and wind erosion. Much of the area has now changed and is dominated by a dense understorey of shrubs. It has been estimated that 20 million hectares of western NSW are either already encroached or highly susceptible to woody weed encroachment.”Booth, C.A., King, G.W., and Sanchez-Bayo, F. (1996). Establishment of woody weeds in western NSW. 1. Seedling emergence and phenology. Rangeland Journal. Vol. 18, Issue 1. pp 58-79.
“While the semi-arid range lands of Australia have historically been regarded as amongst the nation’s greatest assets, millions of hectares have unfortunately deteriorated considerably due to the spread of unpalatable native shrubs on open grazing lands. As a consequence of the reduced feed available on infested land, livestock and native animals graze more heavily on unaffected areas, which in turn become more susceptible to erosion and to further invasion by shrubs.”Daly, R.L., and Hodgkinson, K.C. (1996). Relationships between grass, shrub and tree cover on four landforms of semi-arid eastern Australia, and prospects for change by burning. Rangeland Journal. Vol. 18, Issue 1. pp 104-117.
“The range of grass, shrub and tree levels present in the Louth region of western NSW was determined in an area where woody weeds are considered to be rampant, and the prospects for change by burning were evaluated. The survey confirmed the perception of pastoralists, administrators and scientists that shrub cover is unacceptably high for pastoralism throughout much of the region. Additionally, the perennial grass cover was very low and this would increase the instability of forage supply to pastoral herbivores.”CSIRO. Media Release – “No Half Measures to Deal with Woody Weeds.” May 15, 1998.
“Woody weeds have been a problem for more than a century. Since the first two decades of pastoral settlement, there has been a vast area affected by increasing density of the shrubs, largely as a result of declining fire frequency. Some 35 million hectares or 25 per cent of NSW is affected.” Dr Jim Noble, CSIRO Wildlife and Ecology.Blueprint for a Living Continent. A Way Forward from The Wentworth Group of Concerned Scientists (Nov 2002).
“Clear distinction needs to be made between the need to stop broadscale clearing of remnant native vegetation and the need to control shrub invasion in the semi-arid and arid pastoral areas of Australia. This part of Australia has been managed by indigenous Australians for 45,000 years, using fire. Since European settlement these fire management practices have changed which is causing environmental damage in some areas.”
Landholders in western NSW and Queensland may have felt some relief last Sunday with well known journalist Ross Coulthart acknowledging the very real problem of invasive woody weeds. But it appears the Wilderness Society is now going to ignore the event and the issues it raised. There has been no official response from the organisation; no media release attempting to justify their position. I guess this strategy makes it difficult for landholders to get any traction on the issue in the mainstream media? How do you have a debate when one side won’t debate?
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.