He said National Parks and Wildlife Service botanists were particularly concerned about heathlands in the park. While some plants can reshoot from the same rootstock after fires — and their recovery is fairly rapid — those relying on seeds are more problematic. They may not have had enough time to mature since the last big burn.

The National Parks and Wildlife Service director general, Brian Gilligan, said the bushfires were a scientific and ecological tragedy.

MORE than half the Royal National Park south of Sydney was destroyed yesterday afternoon — leaving the world’s second oldest national park facing devastation for the third time in a decade.

There were fears much of the 16,000ha park would be burnt out by this morning.

The park was severely burnt in 1994 and was again under threat from bushfires in 1997.

The National Parks and Wildlife Service director general, Brian Gilligan, said the bushfires were a scientific and ecological tragedy.

But few fire-fighting resources were directed to preserving it yesterday — the more urgent priority was saving life and property.

The coastal park on the city’s southern fringe has long been a fixture of Sydney life. Ornithologists claim it has more bird species than any other park in the country, including the Northern Territory’s Kakadu.

“It’s fundamentally too soon for the park to be comprehensively burnt again,” Mr Gilligan said.

National Parks research indicated that while some species, such as kangaroos and pigmy possums had recovered after 1994, only one koala was spotted in the latest survey.

Botanists are also concerned about plant populations.

“The difficulty we face with the frequency we are dealing with now is when the plant community don’t have enough time to recover you get a gradual change or reduction in biodiversity,” Mr Gilligan said.

He said National Parks and Wildlife Service botanists were particularly concerned about heathlands in the park. While some plants can reshoot from the same rootstock after fires — and their recovery is fairly rapid — those relying on seeds are more problematic. They may not have had enough time to mature since the last big burn.

Altogether, 100,000ha of national parkland across the state has been burnt. Parks and remote walking tracks will remain closed until further notice.