Researchers in Australia are building a “living seed bank” to protect the continent’s last remaining rainforests from climate change. One goal is to prevent the extinction of ancient trees whose ancestral roots can be traced back to Gondwana, the supercontinent that existed before Earth’s continents separated hundreds of millions of years ago.
Historically, Australia’s lush Big Scrub Rainforest thrived on 185,000 acres (75,000 hectares) of eastern Australia. But over the centuries, human intervention and bushfires have reduced it to just 1% of its original area. Now, rising temperatures and drought threaten the remaining fragments.
These smaller patches have fewer trees and less diversity, making species vulnerable to changing weather conditions, warming and disease.
This is particularly worrying for species that descended from Gondwana, such as the red carabene (Carp benthamiana) and Yellow Caravan (Sloanea wolligii) originate from lineages dating back more than 50 million years, a time when Australia was still attached to Antarctica before Gondwana completely broke up.
These canopy trees can grow to heights of 35 and 50 metres respectively and are “the main builders of the forest framework”, according to Robert Kooymana plant biologist at Macquarie University in Australia who is involved in the research.
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In the new project, called Science saves rainforestsmanaged by the Australian non-profit Big Scrub Rainforest Conservancy, scientists have selected 60 plant species, including several trees from the Gondwana era.
For each species, they collected DNA from leaf samples of dozens of plants across their geographic range, to build each species’ genome. Geographic distribution matters, Kooyman said: “What we get from that is a measure of how much diversity a species has in its genome, and how much of that diversity is structured relative to climate variation.”
This reveals the genetics of rainforest plants that can thrive in warmer, drier environments that more closely resemble the climate conditions of the future.
Using the genome, researchers can then identify and collect populations of each plant species that collectively contain as much of the diversity revealed by the genome as possible, including populations better equipped to withstand climate stress.
These plant candidates are currently being propagated and will be grown in a 15 hectare research plantation in New South Wales, called the ‘living seed bank’. In about five years, the propagated trees will be ready to be planted in the remaining forest fragments.
The hope is to transform those patches into diverse landscapes that resemble a larger, intact rainforest. And for species facing climate threats, the plantation provides a resource from which they can select and “move material that increases their ability to cope,” Kooyman said. For trees from ancient lineages, like the Gondwana-descended Carabens, this could be an essential toolkit for survival.
“I admire the positive attitude and the confidence in plant genetic science from those involved,” Sebastian Pfautsch, a researcher who has studied how trees respond to climate stress and was not involved in the study, told Live Science. He is cautious about the overall goal, however.
Pfautsch’s own research has revealed — through controlled experiments with eucalyptus species — that the ability of trees to adapt to higher temperatures may be limited. Pfautsch, who is a professor of urban planning and management at Western Sydney University, also raised concerns about the project’s reliance on public donations to keep it afloat: “Continued funding from the state and federal government is crucial to ensure the growth of the trees,” he said.
Kooyman remains optimistic, however, and believes the project can provide a blueprint for future genetic work — not just in rainforests, but in other threatened ecosystems worldwide. “It’s a starting point to show what’s possible,” he said.