Submissions to the Vegetation Management Legislation 2016 inquiry lack credibility

Submissions to the Vegetation Management Legislation 2016 inquiry lack credibility

The current Queensland Government’s proposed Vegetation Management (Reinstatement) and Other Legislation Amendment Bill 2016, was recently defeated leaving the opportunity for indiscriminate land clearing to continue with the associated loss of habitat, loss of biodiversity and nutrient run-off into rivers flowing onto the Great Barrier Reef, to say nothing about the impact on carbon sequestration.

The vote was taken after a Parliamentary inquiry which received 689 submissions. One of the aspects under consideration was the need to re-establish the requirement to retain buffer zones of natural vegetation along river banks.

Many submissions (numbers 55, 220, 232, 249, 251 for example amongst others) to the inquiry stated that there was no scientific evidence to support the need for a buffer of natural vegetation along river banks. Given this claim, it seemed to be of value to determine if there is any data that supports the value of buffers on river banks.

The streamside forest buffer

The streamside forest buffer

In essence the claim that there is no scientific evidence to support the value of buffers on river banks is completely and totally false and highlights the lack of credibility of many submissions.

In 2010, a very comprehensive and detailed report was generated by Birgita Hansen, Paul Reich, P. Sam Lake and Tim Cavagnaro from the School of Biological Sciences, Monash University, for the Victorian Government and is available at http://www.ccmaknowledgebase.vic.gov.au/resources/RiparianBuffers_Report_Hansenetal2010.pdf

The report is extremely well referenced with around 400 citations. Further, in appendix I, there are extensive references to literature from Australian studies; outlining the required buffers to achieve specific outcomes such a nutrient control, filtration or erosion control.

For example; in Price, P., Lovett, S. & Lovett, J. (2005) Managing riparian widths,( Fact Sheet 13, Land and Water Australia, Canberra); it is considered that buffers of between 5m and 30m are required to achieve erosion and nutrient control in rivers and streams and between 20m and 250m to achieve good water quality in wetlands.

In a second example, Fellows, C.S., Hunter, H. & Grace, M. (2007) Managing diffuse nitrogen loads: in-stream and riparian zone nitrate removal. Salt, Nutrient, Sediment and Interactions: (Findings from the National River Contaminants Program. S. Lovett & P. Price & B. Edgar. Land and Water Australia, Canberra) , identified that denitrification potential in the riparian zone is similar when either woody versus non-woody forms are present. However the authors suggest that the presence of nitrogen-fixing species like Acacia, may well have higher denitrification potential than sparsely treed zones. This may be significant in managing nutrient run-off in Queensland where Acacia regrowth is a major concern.

Typical erosion pattern in an Australian creek running through farmland

Typical erosion pattern in an Australian creek running through farmland

The authors, in reviewing the scientific literature, came up with a set of recommended buffers to achieve particular outcomes in differing land use scenarios of between 30m and 200m depending on the situation and the desired outcome. They were also able to give a level of confidence in the recommendations. While this was aimed at land use in Victoria, many of the principles would be applicable nationwide. Quite a few of the references are based on studies in Queensland.

Hence claims that there is no scientific data to support the benefits of riparian zone buffers are totally false and undermine the credibility of many submissions to the inquiry.

 

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