By Lucien Wilkinson

New Curtin research has found that soil microbes can be used to improve the often expensive and time-consuming process of assessing the effectiveness of ecological restoration projects at abandoned mine sites.

The research, conducted at three sites across Western Australia and published in Science of the Total Environment, found that soil microbes including bacteria and fungi could be surveyed quickly and cheaply using eDNA methods in order to assess and improve mine site restoration practices.

Lead researcher PhD student Mieke van der Heyde from the ARC Centre for Mine Site Restoration in Curtin’s School of Molecular and Life Sciences, said the research was carried out at sites in the Pilbara, Jarrah Forest and Perth area and provided a greater understanding of the importance of soil microbes in rebuilding ecosystems.

“There are thousands of former mine sites in Australia and restoring them in order to create self-sustaining ecosystems is important but also expensive and challenging,” Ms van der Heyde said.

“Currently, in order to assess how a restoration project is progressing, teams of experts must be sent to remote locations, for weeks at a time, to identify plants and perform other monitoring, however this doesn’t necessarily reveal how other aspects of the ecosystem are recovering.

“Soil microbes are the building blocks of ecosystems and good indicators of ecosystem health, but are often overlooked in restoration monitoring.”

Ms van der Heyde said the research demonstrated that eDNA sequencing was an effective approach for monitoring the complex changes in soil microbial communities following mine site restoration.

“Soil microbes can be surveyed quickly and cheaply using eDNA methods, which involves extracting DNA from the soil and sequencing certain ‘barcoding’ regions to determine which bacteria and fungi are present,” Ms van der Heyde said.

“Our results showed that soil microbes can provide a snapshot of ecosystem recovery, but it depends on the region and whether you look at fungi or bacteria.

“Fungi for example, only showed recovery-like patterns in the Jarrah Forest, a system which has large networks of symbiotic fungi, whereas in the Perth region and Pilbara, the fungi looked functionally the same between restored and reference sites, meaning the technique is not ‘one size fits all’ and that environmental conditions need to be taken into account.”

Researchers hope the technique will be adopted by others and used to improve mine site restoration practices and provide a greater understanding of the importance of soil microbes in effectively rebuilding ecosystems.

The article, ‘Changes in soil microbial communities in post mine ecological restoration: Implications for monitoring using high throughput DNA sequencing’, is available online here.