Plant communities of the ironstone ranges of South Western Australia: hotspots for plant diversity and mineral deposits

Plant communities of ancient banded iron formation ranges of South Western Australia occur as islands in a matrix of the largest remaining area of Mediterranean woodlands and shrub lands on the planet. These xeric shrub lands are structurally and compositionally different from the surrounding matrix and exhibit high levels of endemism and species turnover that cannot be ascribed to geology or current climatic gradients. The pattern of the vegetation and flora on these ranges appears to be related to local topographical factors and the long period of time these landscapes have remained unglaciated and above sea level. Similar patterns have recently been described for iron outcrop communities in Brazil. In both regions these communities are being significantly impacted by mining. The high correlation between local endemism and restricted plant communities and high grade mineral deposits presents difficult challenges for achieving a comprehensive, adequate and representative reserve system in South Western Australia.