Mine site restoration needs more time: Australian researchers

Researchers with the Centre for Mine Site Restoration, an initiative at Curtin University near Perth, Western Australia, released a report where they state that more time is needed to allow for adequate mine site restoration practices.

“After a mining operation ceases, there is often less than ten years given to adequately restore the used land back to a sustainable ecological landscape, but the timeframes required for soils and plant communities to develop naturally on tailings is at odds with this short deadline, especially across different climatic zones,” the lead author of the study, Adam Cross, said in a press release.

According to Cross, the mining industry is being asked to achieve thousands of years of natural soil development in under a decade. “We’re not saying it can’t be done – we’re just saying it needs more time and industry need tools that can help predict the trajectory and resilience of restoration at early stages,” he said.

After analyzing tailing samples from the processing of magnetite ore, Cross and his team realized that they were different from natural soils in the region. Specifically, they contain no clay minerals, exhibit virtually no microbiological activity, and their chemical characteristics are “biologically challenging.” Thus, when these effluents are returned to the earth, they don’t match the composition of the original, pre-mining landscape.

Based on previous studies that have shown that natural microbes can assist in soil development and foster effective plant growth, the Centre for Mine Site Restoration’s research highlights the need for the early establishment appropriate microbiota in tailings to adequately prepare the soil to sustain vegetation, before revegetation can begin. “Adequate restoration is much more than simply sprinkling some seeds and planting some trees – ecologists need to prepare the soil layer by layer, introducing microbes to create a sustainable foundation and then move on to the above ground landscaping – a process which takes a considerable amount of time,” the scientist explained.

The research paper “One giant leap for mankind: can ecopoiesis avert mine tailings disasters?” was published today in Nature’s Plant and Soil.