Tasmanian researchers are warning that many plant species are on the verge of disappearing because global warming is reducing the main nutrient in plant growth. Nitrogen is absorbed by plants from the soil, and there are fears that rising carbon dioxide levels from the burning of fossil fuels is reducing its availability.

Researchers from the University of Tasmania's School of Plant Science have been running an experiment for seven years in grasslands at Pontville, north of Hobart. UTAS researcher Dr Mark Hovenden says it's a compelling case for reducing greenhouse emissions.

"The amount of nitrogen is chronically deficient in most of our soils and so if that small amount that's there is reduced even further it could have disastrous consequences, really tipping the balance if you like and pushing a lot of plant communities to change dramatically where you get a disappearance of a lot of species," said Dr Hovenden.

(ABC, 13/11/2008)