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https://www.theguardian.com/australia-news/2024/oct/13/nightcap-national-park-rainforest-trees-age-bushfires-impact>
"Thousands of years of accumulated leaf fall makes the ground bounce like a
mattress underfoot and, high above, rainforest coachwood trees form a dense
canopy that dresses the understory in permanent shade.
Some of the unique plants in this rainforest can trace their lineage back 40 or
50m years when the Gondwana supercontinent was breaking apart and Australia was
detaching itself from what is now Antarctica.
Take only a few steps from the cool shade and you emerge to something
altogether different. Still rainforest, but changing fast.
Soil and rocks are exposed and, above, the leafless branches of tall and dead
trees let the sunlight strike the forest floor.
This is a place packed with threatened species, including the nightcap oak – a
true Gondwanan relic that grows nowhere else.
On the ground and at the base of the thin-barked trees is charcoal. Five years
ago, chunks of this rainforest not evolved to burn, did burn, during what
became known as Australia’s black summer bushfires.
“It can take a lot of these trees a long time to die. It is a long, slow
death,” says Dr Robert Kooyman, an evolutionary ecologist who has spent more
than 40 years working and studying the rainforests in and around Nightcap
national park in northern New South Wales.
About 73,000 sq km of forest were burned in the east and south of the country
during black summer and the fires scorched the habitat of about 3 billion
native animals.
Half of the world heritage-listed Gondwana rainforests – a network of 40 parks
and reserves – were affected by the fires that were driven by global heating.
Fires burned into about 10% of the rainforest in the Nightcap area and affected
about 30% of the rainforest’s margin, says Kooyman.
Kooyman discovered the nightcap oak in the late 1980s. Unlike Australia’s many
eucalypt species, rainforest trees have not evolved to deal with fire.
“It burns around the base and it cooks the cambium layer – the live wood – and
the bark. It triggers this slow-motion death and you can see the progressive
stages here,” he says, pointing to trees in various stages of that slow death.
The fires killed about a third of the mature nightcap oaks, he says, leaving
181 behind. Kooyman’s monitoring shows 72 of those are struggling to survive,
or have lost their main stem and now persist “as suckers only”.
“That one’s on the way out,” says Kooyman, pointing to a nightcap whose bark
and stem is split and is covered by fungi.
“That one is failing too,” says Kooyman, pointing to another. “And this was a
low-intensity burn.”"
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
