THE 65th Annual Symposium of the International Association for Vegetation Science (IAVS) was held at Opal Cove Resort in Coffs Harbour from Sunday 3 to Friday 8 September.

According to Emeritus Professor in Ecosystem Management Nick Reid from the University of New England, which helped organise the conference, the Symposium was possibly the first international environmental conference held in Australia since COVID-19.

320 delegates from more than 20 countries gathered for the six-day conference.

Half of the delegates were from outside Australia and many of the other half were from New South Wales.

Forestry Corporation NSW (FCNSW) sponsored and helped organise the conference.

Their stewardship staff and ecologists spoke at the event and conducted field trips for delegates to state forests on the Coffs Coast.

Professor Reid said it was a very successful annual symposium, with three or four concurrent sessions each day.

“There were six fantastic plenary speakers,” he said.

“They were very sobering about the effects of global warming on vegetation world-wide and expect things to be different in the future.”

Dr Craig D. Allen, a retired research ecologist with the U.S. Geological Survey and an adjunct professor at the University of New Mexico, gave a grim prognosis for the world’s historical forests under unabated climate change.

He said hotter, drier droughts are driving extensive tree mortality in all major forest types world-wide, especially the largest oldest trees.

“The largest and most charismatic old trees around the globe, which we all love and admire, are now at risk from climate change,” Dr Allen told the conference.

“The biggest trees might be only one percent of the trees in old forests, but are responsible for 50 percent of the stored carbon.

“The tallest trees increasingly struggle to get water up to their leaves for photosynthesis when the atmosphere becomes so hot and dry, resulting in dieback and then replacement by different, shorter, younger species.

“Even the eucalypts here in Australia have their limits and are not immune to the impacts of climate change.

“We are now seeing mass mortality in eucalypt forests across Australia.”

Dr Allen said as global climates increasingly diverge from the documented range of historical variability, previously unseen tipping points or thresholds are being crossed, and historically unprecedented ecosystem surprises are emerging.

“Climate change is accelerating further because those tropical and boreal forests that are so important in storing a lot of our excess greenhouse gases are now episodically bleeding huge pulses of carbon dioxide back into the atmosphere, as more and more historical forests are destroyed and replaced by less carbon-rich types of vegetation.”

Conference delegates had opportunities to tour the Mid North Coast.

After the tours, the Council of the Association passed a resolution asking for the cessation of native forest logging, although this was not part of the conference output.

Dr Angus Carnegie, head of Forest Science with the NSW Department of Primary Industries, showed conference delegates a small stand of scrub turpentine (Rhodamnia rubescens), infected with myrtle rust, in the forest hinterland of Coffs Harbour, and explained that the stand’s fate was effectively sealed.

“This stand and every other stand of scrub turpentine and native guava trees I know of up and down the NSW coast are now functionally extinct in the wild,” he said.

Dr Carnegie said if other strains of the myrtle rust fungus are allowed to enter the country, they have the
potential to threaten Australia’s iconic eucalypts, so Australia’s biosecurity is paramount.

Many of the presentations were on a more positive note.

Professor Reid said two wonderful indigenous speakers, Oliver Costello from the Bundjalung people of the Northern Rivers and Teagan Goolmir from the Arabanna people of South Australia, advised that vegetation science in Australia needs to be done in consultation with Indigenous people, leading to better outcomes.

By Andrew VIVIAN