RESEARCH is underway to determine how much salinity native vegetation can withstand. The three-year project funded by the National Dryland Salinity Program (NDSP) on risk and restoration potential for remnant vegetation is being led by Professor Richard Hobbs of Murdoch University in Perth. "The south-west of WA has been listed as one of 25 biodiversity hot-spots in the world ‹ the only one in Australia," Professor Hobbs said. "Salinity is one of the major reasons that so many species are under threat and this work will assist in finding solutions." Until now, most research funded by the NDSP has concerned the impact of salinity on agricultural land. Expansion to include native vegetation acknowledges the need to fight salinity on a catchment basis. The Department of Conservation and Land Management has estimated that between 300 and 800 species of native plants risk extinction from rising salinity. Professor Hobbs said that, while it was probably impossible to restore much of the bush affected by salt since clearing for agriculture took place, it might be possible to establish vegetation communities that still had conservation value, for example by substituting more salt-tolerant species. This could help reduce further losses. "At present, we know very little about the physiology of many native species in areas affected by salinity," he said. "We know what plants look like and where they grow, but their tolerance of salinity and waterlogging is often a complete mystery. "Until such gaps in our understanding are filled, attempts to protect and retain remnant vegetation will be difficult." The new research will concentrate on the upper and middle areas of the Blackwood River Basin (between Dumbleyung and Boyup Brook). This area was chosen because the catchment contains a range of habitats and relatively good information is available. "The community needs better advice on management of remnant vegetation at risk from salinisation, and we should be in a much better position to assist on completion of this project," Professor Hobbs said.