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WA State Barrier Fence

Thursday, 31 October 2013  | 

The Western Australian Government has committed $6.5m to extend the existing 1170 km State Barrier Fence. The fence is designed to reduce stock losses by dingoes and prevent emu and kangaroo damage to wheat crops. Once completed, the fence will form a largely continuous barrier that runs through five bioregions from North of Geraldton to Cape Arid. The extension will cut through the largest intact temperate woodland on earth, the Great Western Woodlands. The 490 km extension would separate 300,000ha of contiguous bush from the main block. The fence will impact biodiversity in three main ways: by restricting emu dispersal, limiting dingo populations and subdividing populations of many native species whose dispersal is limited by barriers.

  1. The existing State Barrier Fence restricts the flow of tens of thousands of emus during migration years. Emus disperse seeds of many plant species over long distances. In the absence of this dispersal, plant species may decline across large areas as isolated populations die out. Further, without long-distance dispersal, some plant species will not be able to respond to climate change by shifting their distribution.
  2. The fence is designed to prevent dingo re-establishment in the west and south. In areas where dingos are poisoned, foxes, cats and large herbivores increase in abundance, while small and medium sized mammals, and some plant species decline. There is a body of evidence suggesting that dingos can exclude foxes and cats, to the benefit of smaller mammals, and dingos reduce kangaroo numbers, reducing herbivore impacts on plants.
  3. The fence may fragment the distribution of native species including small mammals and some reptiles. There are no studies examining the barrier effect of the fence on non-target species so it is uncertain how many non-target species will suffer fragmentation in addition to the plants that emus disperse.

Supporting Research

Calvino-Cancela M., Dunn R. R., van Etten E. J. B. & Lamont B. B. (2006) Emus as non-standard seed dispersers and their potential for long-distance dispersal. Ecography 29, 632-40.
examine potential for emus to act as long distance seed dispersal vectors
Wallach A. D., Johnson C. N., Ritchie E. G. & O'Neill A. J. (2010) Predator control promotes invasive dominated ecological states. Ecol. Lett. 13, 1008-18.
to investigate the consequence of predator control on ecosystem resilience to invasive species
Lasky J. R., Jetz W. & Keitt T. H. (2011) Conservation biogeography of the US-Mexico border: a transcontinental risk assessment of barriers to animal dispersal. Divers. Distrib. 17, 673-87.
to identify species most at risk of barriers that may significantly impede animal migrations along the US-Mexico border
Driscoll D. A., Felton A., Gibbons P., Felton A. M., Munro N. T. & Lindenmayer D. B. (2012) Priorities in policy and management when existing biodiversity stressors interact with climate-change. Clim. Change 111, 533–57.
review the interactions of climate change with existing threats to biodiversity, including habitat fragmentation
Kennedy M., Phillips B. L., Legge S., Murphy S. A. & Faulkner R. A. (2012) Do dingoes suppress the activity of feral cats in northern Australia? Austral Ecol. 37, 134-9.
to determine if dingo density is correlated with cat density in northern Australia
Moseby K. E., Read J. L., Paton D. C., Copley P., Hill B. M. & Crisp H. A. (2011) Predation determines the outcome of 10 reintroduction attempts in arid South Australia. Biol. Conserv. 144, 2863-72.
to review the success or failure of reintroductions into a predator proof enclosure at Arid Recovery
He T. H., Lamont B. B., Krauss S. L., Enright N. J., Miller B. P. & Gove A. D. (2009) Ants cannot account for interpopulation dispersal of the arillate pea Daviesia triflora. New Phytol. 181, 725-33.
assess seed dispersal
Ferronato B. O., Roe J. H. & Georges A. (2014) Reptile bycatch in a pest-exclusion fence established for wildlife reintroductions. J. Nat. Conserv. 22, 577-85.
assess the effect offences on movements and mortality in a reptile community, andenvironmental factors that explain these parameters that may beused to predict times and locations of highest concern