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3 Jun 2019

The science of propagation

 Over the last two years horticulturists at the Australian Botanic Garden Mount Annan Nursery have dramatically increased the number of threatened species they are propagating, growing and returning back into the wild.

These plants cover a broad spectrum of species including 647 that were identified as threatened in NSW from the last State of the Environment Report in 2015. Meeting this demand requires equal scientific and horticultural practice if conservation efforts through translocation are to be successful. Some of the team can be seen in the short video below or extended video at the bottom of this page.

Propagation trials

The horticulturists at the Nursery work closely with scientists from the Australian PlantBank to continually learn and refine their skills as new species, many of which have never been propagated, are put through various trials.

Most of the seed germination trials take place in the PlantBank while all vegetative propagation trials happen in the Nursery. Where these plants will be permanently translocated depends on the species, soil type, climate and surrounding plant community. 

Hibbertia puberula subsp glabrescens 2.jpg
Hibbertia puberula subsp glabrescens is listed as critically endangered.

Translocation attempts

To remain up to date on the latest research, thinking and to share what we have learnt, representatives from the Garden participated in the recent Australasian Plant Conservation Conference in Canberra, which is a biennial event in Australia that highlights plant conservation issues.
The Australian Network for Plant Conservation (ANPC) brings together conservation researchers and practitioners from across Australia to discuss the recent advances and latest scientific findings for successful threatened plant translocations. Species translocations have been an important conservation approach for more than two decades to save threatened species from extinction.
Learnings from our many threatened species projects are being applied to the conservation work at the future Nancy-Bird Walton Western Sydney Airport where we are attempting to conserve three species impacted by the construction, one of which is Pimelea spicata.

Only a few small populations of these plants remain in western and southern Sydney. 
pimelea spicata cutting
Horticulturists and researchers are treating plants that have never been propagated before.

Plants in peril

Once widespread on the Cumberland Plain, Pimelea spicata the Spiked Rice-flower occurs in two areas: the Cumberland Plain and the Illawarra. On the Cumberland Plain it is associated with Grey Box communities and can be found in areas where Ironbarks thrive.

Less than 30 sites remain for this species, and the objectives of the project are to assess genetic diversity and genetic structure across the remaining distribution. We will also be investigating their genetic and environmental diversity.

seed collecting
Horticulturalists and researchers collect seeds from the Western Sydney Airport to propagate in the Nursery.

Genetic research

For the first time, this study will provide a regional genetic perspective for this threatened species, and an understanding of genetic health, population structure and genetic diversity patterns to support long term conservation and management.

Given the size and regional significance of the Pimelea spicata population at the Western Sydney Airport, this population will receive targeted genetic sampling to help us understand the overall context of the species’ genetic spectrum.

Other species included in our current conservation projects include Marsdenia viridiflora, Hibbertia puberula subsp glabrescens, Senecio linearifolius var dangarensis, Allocasuarina portuensis, Hibbertia fumana, Persoonia species, Eucalyptus cattai and Zieria covenyi.

plant cuttings
Plant cuttings from the wild are propagated in the Nursery for conservation research and translocation projects.

Go behind the scenes

Or take an audio adventure with Australian Botanic Garden Mount Annan Curator Manager, John Siemon, and Graham Ross to learn more about the Garden by clicking play on the Branch Out episode below. 

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