Up to three-quarters of the biodiversity living on Western Australia’s iconic Ironstone Mountains in the state’s Mid West (known as Banded Iron Formations) could be difficult, if not impossible, to quickly return to its former state after the landscape has been mined, according to a study from Curtin University. find.
Research, published in Ecology and Evolution, found that plant ecosystems are well adapted to the characteristics of ancient, nutrient-poor soils in the region – and that the vastly different characteristics of mined landscapes mean that many native species are unlikely to develop. be restored by rehabilitation. .
Principal investigator Dr Adam Cross of Curtin’s School of Molecular and Life Sciences said the elevation and different habitats offered by Band Iron Formations (BIFs) in an otherwise dry, mostly flat landscape , make them a sponge for biodiversity – but their iron-rich rock made them increasingly attractive to iron miners.
“Unfortunately, the chemical characteristics of some tailings and other mine-produced by-products may be more similar to the materials on the moon than to the ancient heavily weathered soils of the BIF, which presents a really difficult and hostile environment for many natives. . plant species, ”said Dr Cross.
The Mid West region is known for its BIF ranges, which Dr Cross describes as superb natural ‘museums’, which are home to much of the biodiversity of regional florists. He said almost every plant species in the surrounding landscape is found there – as well as some unique species that cannot be found anywhere else.
“These collections of species have accumulated over very long periods of time and the increased pressure to exploit the BIF is putting biodiversity at risk. Once the BIF is gone, that’s all – we can’t recreate these iconic landforms, and our study suggests that even if we could, the post-mining environment likely wouldn’t support most of the species that once called them. .
“BIFs are home to such biodiversity because in times of warmer and drier climates, their rocky and complex soils provided cooler, wetter refuge for many species that were unable to survive in the surrounding landscape.
“With climate change suggesting a warmer and drier outlook for the Mid West region in the decades to come, it is increasingly important that we preserve and conserve the remaining BIF habitats and the species that grow there.
The research team studied 538 plant species in an 82,000 hectare area in the Mid West of WA, evaluating their growth on different types of soils in the area and examining their potential tolerance to the chemical characteristics of the extracted materials.
Although many species have been adapted to the acidic, nutrient-poor soils of BIF, the team found that at least some were tolerant of a wide range of soil types and could be used as ‘pioneers’. to help revive the reestablishment of vegetation during rehabilitation.
Dr Cross said more studies were needed to find ways to quickly change the chemical characteristics of post-mining soils to speed rehabilitation and preserve the biodiversity of the area.
“The mining industry must take into account the soil properties of landforms requiring ecological rehabilitation or restoration, as well as the implications for vegetation establishment and plant community development, at the very early stages of planning or environmental impact assessment, ”said Dr. Cross.
“Ecosystems are extremely complex; we need to recognize, appreciate and learn from this complexity as we attempt to restore biodiversity in areas that have been affected by mining.
“We need to strike a balance between development and conservation to effectively continue mining in these areas, while preserving our incredible natural resources.”
The research was funded by the Center for Mine Site Restoration at Curtin University.
The full document Calcicole-Calcifuge Plant Strategies Limit Restoration Potential in Regional Semi-Arid Flora can be found online here.