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Scientists achieve orchid holy grail

In a world first, a self-sustaining population of an endangered orchid species has been created.

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Scientists achieve orchid holy grail

In a world first, a self-sustaining population of an endangered orchid species has been created.

The Colourful Spider-orchid (Caladenia colorata) is endangered nationally with small populations of the plant remaining in just a handful of sites in Victoria and South Australia.

Orchids are notoriously fickle and difficult to reintroduce back into the wild because they are so dependent on having the right environment and ecology.

The Colourful Spider-orchid is part of a decade-long Orchid Conservation Program led by the Royal Botanic Gardens Victoria and includes teams of volunteers, Trust for Nature, Australian Network for Plant Conservation, Wimmera Catchment Management Authority, Department of Environment, Land, Water and Planning, Parks Victoria, Australasian Native Orchid Society, Grampians Threatened Species Hub, and private landowners.

Research Scientist and Orchid Conservation Program leader from the Royal Botanic Gardens Victoria, Dr Noushka Reiter, said this successful reintroduction in the Wimmera region gives scientists the confidence that other endangered orchid species can also be reintroduced.

“This is a fantastic outcome involving the reintroduction of over 700 plants. These plants were subsequently naturally pollinated leading to over 500 recruits,” she said.

“We are now confident this reintroduction is self-sustaining—it’s the holy grail of threatened species reintroductions and a global first for orchid reintroductions.”

Orchids are the epitome of nature’s interdependence: they have a relationship with mycorrhiza fungi in order for seed to germinate and often depend on a single species of pollinator—in the case of C. colorata a particular species of wasp.

The Royal Botanic Gardens Victoria grows the orchids symbiotically with their mycorrhizae and surveys for their pollinators prior to reintroduction.

The conservation program is using protected sites on Parks Victoria land and sites that have Trust for Nature covenants on them, which means they will be protected even if the properties change hands, giving greater long-term certainty of the orchids’ survival.

Trust for Nature Senior Conservation Officer Fiona Copley said the primary threats to orchids are land clearing, weeds, grazing, trampling and thefts by poachers (which means the location of sites is highly guarded).

Fiona said, “For populations to remain viable they need to have their threats managed, relationships between the mycorrhizae and pollinator must remain intact, so a whole lot of environmental conditions need to come together – orchids have a challenging time!

“Putting conservation covenants on native bush helps preserve existing ecological interactions.”

The Orchid Conservation Program also recently found more than 300 flowering endangered Tawny Spider-orchids, Caladenia fulva, growing on a separate covenanted property near the Grampians.  

Main photo: Caladenia colorata. Inset: Caladenia fulva. Photos courtesy Royal Botanic Gardens Victoria.