Pomaderris walshii is a critically endangered plant with only about 80 individuals growing in the wild in and around Budderoo National Park. In the wild there is quite low recruitment seen in new seedlings growing up in the understory. National Parks have been of working with this critically threatened species for almost 20 years and in 2015 through discussions with National Parks and the Office of Environment and Heritage and support from the Saving Our Species Program. Wollongong Botanic Garden joined in by collecting cuttings to build an ex-situ collection (one that is outside its natural population). Having an ex-situ conservation collection like this enables us to back up the wild population should anything go wrong, like a fire or major flood. This species has a very small natural range so if a major flood or fire went through the area the species as a whole could be devastated. In the last few years there have been a few floods which have caused much damage to the wild population, and highlighted the importance of having back up ex-situ holdings.
Our ex-situ collection also supports research projects, which means researchers do not have to affect or damage the wild population to obtain samples to work on. Research carried out with this species from ex-situ holdings include genetic research to understand how diverse and ‘healthy’ this small population is. Other research includes what the response is to fire from seeds, to understand if this species has evolved to withstand fire. This can help us understand if other treatments can assist this species naturally regenerate in the wild by small controlled burns etc.
Over the last 3 years we have been propagating this species and now we have a few hundred in our collection. In November 2018 over one hundred plants of Pomaderris walshii were replanted into the wild from our collections, doubling the wild population, and serving as a research planting to inform further reintroductions of this species. All this work is being done to safeguard this critically endangered species into the future and is just one of the project of this nature Wollongong Botanic Gardens are involved with, all helping our wonderful regional flora. This project is a great example of working in collaboration with different organisations to get great conservation outcomes.