Researchers in Australia are building a “living seed bank” to protect the continent’s last remaining fragments of rainforest from climate change. One goal is to prevent the extinction of ancient trees whose ancestral roots go back to Gondwana, the supercontinent that existed before Earth’s continents split apart hundreds of millions of years ago.
Historically, Australia’s lush Big Scrub Rainforest flourished at 185,000 hectares (75 thousand hectares) of eastern Australia. But over the centuries, human attacks and fires have reduced it to just 1% of that original space. Now, rising temperatures and drought threaten the remaining fragments.
These smaller patches contain fewer trees and declining diversity, which leaves species vulnerable to changing weather, warming and disease.
This is a particular concern for species native to Gondwana such as the Red Carabeen (Carrabina benthamiana) and Yellow Carabeen (Sloanea woolsii) from lineages over 50 million years old, a time when Australia was still connected to Antarctica before Gondwana broke off completely.
These canopy trees can grow up to 115 and 164 feet (35 and 50 meters) tall, respectively, and are “the primary framework builders of the forest,” it said. Robert Koymana plant biologist at Macquarie University, Australia who is involved with the research.
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In the new project, called Rainforests saving sciencewhich is run by the Australian non-profit Big Scrub Rainforest Conservancy, scientists have selected 60 plant species, including some of those Gondwana-era trees.
For each species, they collected DNA from leaf samples taken from dozens of plants across their geographic range to build the genome of each. Geographic distribution is important, Kooyman said: “What we get from this is a measure of how much diversity a species has within its genome, and how much of that diversity is structured in relation to climate change.”
This will reveal the genetics of rainforest plants that are able to thrive in warmer, drier environments that more closely resemble future climate conditions.
Using the genome, researchers can then identify and assemble populations of each plant species that will collectively contain as much of the diversity it reveals as possible—including populations that are better equipped to withstand climate stress. .
These candidate plants are currently being propagated and will be grown in a 37-hectare (15 ha) research plantation in New South Wales, called a “living seed bank”. In about five years, the raised trees will be ready for planting in the remaining forest fragments.
The hope is that those areas will be transformed into landscapes with diversity resembling 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 capacity to deal with it,” Kooyman said. For trees from ancient lineages, such as the Gondwana-derived Carabeens, this may be an essential tool for survival.
“I admire the positive attitude and faith in plant genetic science of the people involved,” Sebastian Pfautsch, a researcher who has studied how trees respond to climate stress and is not involved in the research, told Live Science. However, he is cautious about his overall goal.
Pfautsch’s own research has found – through controlled experiments on eucalyptus species – that the capacity of trees to adapt to higher temperatures may be limited. Pfautsch, who is a professor of urban planning and management at the University of Western Sydney, also expressed concern about the project’s reliance on public donations to keep it afloat: “Continued state and federal government funding is essential to ensure the trees grow. ,” he said. .
Kooyman, however, remains optimistic and believes the project could provide a blueprint for future genetic work — not just in rainforests, but other threatened ecosystems around the world. “It’s a starting point to demonstrate what’s possible,” he said.