Australian researchers reveal open-cut operations can impact ecosystems beyond mining area

9 September 2015 (Last Updated September 9th, 2015 18:30)

New research by Western Sydney University in Australia has found that open-cut mines can have an impact on ecosystems outside official boundaries, which alter groundwater levels.

Pilbara

New research by Western Sydney University in Australia has found that open-cut mines can have an impact on ecosystems outside official boundaries, which alter groundwater levels.

Dr Sebastian Pfautsch from Western Sydney University Hawkesbury Institute for the Environment said: "What we examined in this study is how these trees respond when nearby mine operations start changing underground water supplies."

"Where the water table had fallen to 19m below the surface, water use of trees was much lower compared to trees where the water table remained unchanged at around 6m below ground level."

According to Pfautsch, trees such as eucalypts in Australia can extend 30m deeper roots into the ground to find water.

Pfautsch joined forces with The University of Sydney and Rio Tinto Iron Ore under an Australian Research Council Linkage grant to study eucalypts near open-cut mines in Western Australia's Pilbara region to examine the effect of mining on ecosystems.

"The management of ecological water requirements of trees is essential and has been well-executed in semi-arid landscapes like we studied in the Pilbara, but should also be implemented in other mining regions in Australia."

Published in the international journal Ecohydrology, the study measured the water used by trees at sites where groundwater levels had artificially been lowered or raised and evaluated their health.

Pfautsch said that the water use by trees could be sensitive to changes in ground water levels, some several kilometres away from mining sites.

Pfautsch added: "The management of ecological water requirements of trees is essential and has been well-executed in semi-arid landscapes like we studied in the Pilbara, but should also be implemented in other mining regions in Australia."

Dr Pfautsch's study is expected to have implications for new as well as expanding open-cut mining operations.

The research also highlighted that groundwater levels that fall and rise can impact tree-dominated ecosystems beyond the border of a mine.


Image: Trees can be at risk if mining alters groundwater levels. Photo: courtesy of University of Western Sydney.