South-western Australia is an important agricultural region and one of the world's top biodiversity hotspots - and researchers are trialling a new method to preserve the precious biodiversity that remains on and around farms.
A group led by researchers at The University of Western Australia has received an Australian Research Council Linkage Grant of almost $400,000 to investigate whether phosphorus-resistant native plants - such as the perennial herb Ptilotus polystachyus - can help reduce the damaging flow of phosphorus into groundwater and waterways.
Winthrop Professor Hans Lambers, Head of UWA's School of Plant Biology, said biodiversity hotspots that coexist with farmland are often threatened when phosphorus - used in fertilisers - leaches into waterways and adversely affects, in this case, banksia and eucalypt woodlands and seasonal wetlands adapted to low phosphorus soils.
"We are hoping to find out if it's possible to use certain phosphorus-resistant native perennials strategically to retain the phosphorus in farmland soils," he said.
Professor Lambers said landscapes are often a patchwork of farms and remnant natural ecosystems. Phosphorus runoff threatens biodiversity by eutrophication in which a river or wetland acquires a high concentration of nutrients, especially phosphates and nitrates. These promote excessive growth of algae which dies and decomposes, depleting the water of available oxygen and causing the death of other organisms, such as fish.
"We will develop a detailed understanding of the mechanisms, timing and magnitude of phosphorus release from farmland into shallow groundwater and waterways in the Peel-Harvey region," Professor Lambers said.
"We will also determine the capacity of phosphorus-resistant native plants in pastures and rehabilitation sites to absorb phosphorus, and the environmental and biological factors that affect this capacity."
UWA's partners in the project are Greening Australia (WA), the Alcoa Foundation, the Harvey River Restoration Taskforce Inc, Alcoa Farmlands, the Department of Agriculture and Food WA, the National Measurement Institute, and Rothamsted Research and Cranfield University, both in the United Kingdom.
Winthrop Professor Hans Lambers (Head, UWA School of Plant Biology) (+61 8) 6488 7381
Associate Professor Megan Ryan (Frank Ford Associate Professor in Pasture Science) (+61 4) 39 985 366
Michael Sinclair-Jones (UWA Public Affairs) (+61 8) 6488 3229 / (+61 4) 00 700 783