Ageing River Red Gum: Developing a
DNA-based tool to make it easier
Aquatic ecologists with Queensland's Department of Regional Development, Manufacturing and Water (DRDMW) are working with CSIRO, ANSTO and other Queensland departments on a project that aims to build an "epigenetic clock" for river red gum (Eucalyptus camaldulensis).
This project will identify changes that occur in the tree's DNA as it ages and correlate these changes with tree age. This will enable botanists, ecologists and foresters to determine tree age using a tissue sample of only fifty milligrams, rather than using the more destructive techniques currently available.
To make this a reality, DRDMW scientists are looking for tissue samples from river red gum trees of known age.
DRDMW project lead Dr Janice Kerr said the project needed trees older than 30 years to create the epigenetic clock.
"We have identified trees of known age up to about 30 years, but to build a useful tool, we need known age specimens of up to 120 years or more," she said.
"We know that the river red gum can live for 350 years, but we consider it unlikely that precise records of trees of this age will exist, so ANSTO is helping to age some larger trees with radiocarbon dating and tree-ring analysis.
"The epigenetic clock technology has been used in the past to develop a non-destructive method for aging endangered fish species, including lungfish, Murray cod and Mary River cod. This was very successful, and work is underway to repeat this for golden perch, bass and green sea turtles," Dr Kerr said.
"We are now keen to develop the method for trees, and we are targeting Australia's favourite tree - the river red gum," she said.
Knowing tree ages will help determine whether tree populations are reproducing at a sufficient rate to remain stable and allow water scientists to ensure that populations have the space and water they need for continued health.
On project completion, the work will be made publicly available in a scientific publication and the technique will become available for wider use through a commercial provider/s of DNA-related analyses.
"We would like to hear from landholders, Landcare groups or managers of gardens, parklands or campuses that have river red gum on their grounds and know the age or planting time of their specimens.
"Landholders may be able to correlate germination of tree stands with flood events. We would then send interested parties a small kit and instructions on how to collect the DNA samples."
For locations close to Toowoomba, Dr Kerr's team could arrange to collect the samples.
"We would also like some extra information about the tree (if known), such as its diameter at chest height, its height, the number of trunks, location information, seed provenance, and of course, age."
Dr Kerr said the new tool would be highly valuable in determining the water needs of river red gums, and thus ensure the future availability of the materials they produce and the habitats they support. This approach may also contribute evidence to support the cultural significance of some trees to indigenous peoples.
If you have a river red gum and you know when it was planted, please contact Dr Janice Kerr at the email address below if you and your gardens are interested and willing to help the team.
Contact Us
Dr. Janice Kerr
Scientist (Aquatic Ecology)
South Region| Water Planning and Science
Department of Regional Development, Manufacturing and Water
E: janice.kerr@rdmw.qld.gov.au
A: 203 Tor Street, Toowoomba QLD 4350 | GPO Box 318, Toowoomba QLD 4350
W: www.rdmw.qld.gov.au
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