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 avoid the extinction of ancient trees whose ancestral roots can be traced 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 on 185,000 acres (75,000 hectares) from eastern Australia. But over the centuries, human encroachment and forest fires have shrunk 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, making species vulnerable to changing weather, warming and disease.
This is a cause for concern, particularly for Gondwana-derived species such as the Red Carabeen (Karrabina benthamiana) and yellow carabiner (Sloanea woollsii) from lineages over 50 million years old, a time when Australia was still connected to Antarctica before Gondwana broke up completely.
These crown trees can grow to 115 and 164 feet (35 and 50 meters) tall, respectively, and are “the primary framework builders of the forest,” said Robert Kooymanplant biologist at Macquarie University, Australia, who participated in the study.
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In the new project, the so-called Science is saving the rainforestwhich is managed by the Australian non-profit Big Scrub Rainforest Conservancy, scientists have selected 60 species of plants, including several of these 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 one. Geographic distribution is important, Koiman said: “What we get from this is a measure of how much diversity a species has in its genome, and how much of that diversity is structured by climate change.”
This will reveal the genetics of rainforest plants that can thrive in warmer, drier environments that more closely resemble future climates.
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-acre (15 ha) research plantation in New South Wales called a “living seed bank”. After about five years, the grown trees will be ready for planting in the remaining forest fragments.
The hope is to transform these patches into landscapes of diversity resembling a larger, intact rainforest. And for species facing climate threats, the plantation offers a resource from which they can select and “move material that increases their capacity to deal with it,” Koiman said. For trees of ancient lineages, such as the Gondwana-derived carabiners, this can be an essential toolkit for survival.
“I admire the positive attitude and confidence in plant genetic science of the people involved,” Sebastian Pfauch, a researcher who has studied how trees respond to climate stress and was not involved in the study, told Live Science. However, he is cautious about its overall purpose.
Pfautsch’s own research revealed—through controlled experiments on eucalyptus species—that the trees’ ability 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 running: “Continued state and federal government funding is critical to ensuring the trees grow “, he said .
Kooyman remains optimistic, however, and believes the project could provide a blueprint for future genetic work — not just in rainforests, but in other threatened ecosystems around the world. “It’s a starting point to demonstrate what’s possible,” he said.
