Australia's declining alpine regions

Posted: 18 June 2001

In an early warning to the rest of the world, Australia's snowy alpine regions are shrinking and could disappear in 70 years because of global warming, Australian scientists say.

"In Australia we could have the complete loss of the alpine ecosystems within the next 70 years," said botanist John Morgan in La Trobe University's latest campus magazine.

A La Trobe study found that sub-alpine trees in the Snowy Mountains have started growing 40 metres (130 feet) higher than they had in the past 25 years as a result of global warming.

"Australia's mountains are just at the limit of alpine, so changes could happen very dramatically here. We may be any early warning system for the rest of the world," said Morgan.

Australia's mountains are low by world standards, with only 100 to 200 metres (328-656 feet) separating the tree-line from the top of some mountains. Yet there are more than 250 species of alpine plants growing in the restricted habitat.

Morgan said the amount and duration of snow was crucial for the survival of alpine vegetation, with some plants dependent on banks of snow not melting until late in the spring.

La Trobe scientists say Australia's Snowy Mountains sub-alpine forest are 300 to 500 years old, suggesting the forest had been stable for centuries.

"We are now starting to see movement in the trees. They are now establishing and growing 30 and 40 metres from the existing tree-line. Every year since 1975 new snow gums have established where they were previously absent," Morgan said.

Morgan said the movement of sub-alpine trees higher up the mountains supported evidence that global warming was changing the pattern of vegetation in the world's alpine regions.

The demise of Australia's alpine ecosystem would mean the end of a small but thriving ski industry worth hundreds of millions of dollars a year.

Australia's highest peak is the 2,228-metre (7,310 feet) Mount Kosciuszko.

Source: Reuters News Service, April 24, 2001.