Developing ex situ propagation techniques and supporting future translocations for threatened orchids in South hub.
The Orchidaceae is well represented on state and federal threatened species lists. In NSW, 81 taxa are currently listed under NSW TSC Act, 25% of which are critically endangered. Threatening processes such as habitat loss, browsing by native and exotic herbivores, small population size and protracted drought have contributed to these declines. In addition to this, catastrophic climate change is likely to place additional pressures on populations in the future.
Ex situ conservation techniques developed for several threatened orchid genera have significantly reduced their risk of extinction. Translocation has enabled threatened species practitioners to increase orchid population sizes, maximise genetic diversity and protect populations from deleterious stochastic events. Furthermore, ex situ conservation techniques improve the adaptive capacity of orchid taxa to survive climate change by providing opportunities to establish new populations in more suitable climate envelopes.
Orchids have crucial relationships with mycorrhizal fungi which are essential for seed germination and plant survival. Consequently, raising plant stock for the purposes of translocation requires complex laboratory techniques to identify and isolate orchid mycorrhizae.
There are several threatened orchid species with conservation projects developed under the Saving Our Species program in NSW. This project aims to develop techniques to effectively germinate and raise seedlings for four species occurring in South Hub – Calochilus pulchellus
, Caladenia tessellata
, Pterostylis despectans
and Thelymitra kangaloonica
. Specifically, the aims are to:
- Isolate and culture the fungi required to germinate the seeds of each species
- Determine the most suitable culture medium for fungal growth and seed germination
- Determine suitable conditions for seedling growth and survival ex situ
- Develop and maintain a collection of plants suitable for translocation
To achieve these aims, the Australian Plant Bank will work closely with Saving our Species SPCs who are responsible for the recovery of the target taxa. Coordinators will provide in kind support for the project by leading field trips to hand pollinate plants as well as collect soil, seed and plant material.
- Development of orchid propagation techniques to enable the establishment of ex situ populations of the target species.
- Identification and isolation of mycorrhizal fungi that play a crucial role in the germination and survival of the target species;
- Symbiotic germination of target taxa.
This project has been supported by the New South Wales Government's Saving our Species program through its Department of Planning, Industry and Environment.