A carefully planned and executed fire in the Adelaide Hills has helped bring a critically endangered orchid back from the brink of extinction.
The naked sun orchid population was down to the last 12 plants, until ecologists and fire experts made the nail-biting decision to burn the area in order to save it.
Natural Resources Adelaide and Mount Lofty Ranges fire ecologist Kirstin Abley said the orchid was being smothered by native coral fern, and something had to be done.
“We realised that we could keep monitoring and documenting their extinction or we could give it a go and try something new.
“We had enough information to suggest that a lack of fire was a key threat, so we decided we needed to be bold and try burning some of these populations.”
In a nail biting exercise, half of the population of 12 orchids were burnt and the other half left unburnt, just to be on the safe side.
The burn was a huge success, with a count done this summer showing the population has increased to 83 plants.
“Burning areas like swamps is tricky, particularly if you only want to burn part of the swamp. Swamps have high fuel loads that are very flammable – getting them to burn is easy, stopping parts of them from burning is much harder,” said Kirstin.
It took a massive effort and very careful planning to protect the chosen six plants from burning, with hours of brush cutting, installation of sprinklers, and with fire fighters positioned in the swamp itself.
“The level of skill the fire management team have developed in planning and conducting prescribed burns is amazing – it gives us the confidence to undertake complex burns like this. The rewards are proving priceless.”
The orchids will be monitored over next few years to see how well they flower and set seed, assisted by the Native Orchid Society of South Australia.