National Threatened Species Day 2023: Central Victoria’s Ballantinia
Posted on 7 September, 2023 by Hadley Cole
National Threatened Species Day on 7 September each year aims to raise awareness of plants and animals vulnerable to extinction across Australia. According to Nature Conservancy Australia, we have 100 endemic Australian species that have been declared extinct as of March 2021.
Threatened Species Day offers a moment to pause and reflect on how we can conserve and protect Australia’s vulnerable and often unique species from becoming extinct. Many of Australia’s threatened species have become so due to human activity such as land clearing, the introduction of non-native pest and weed species and climate change which has lead to the fragmentation of native species populations. Often the solution to protecting threatened species is through human intervention in the conservation, restoration and enhancement of habitat and biodiversity.
Sadly, in Central Victoria we have numerous threatened species including flora and fauna. A lesser known but precious endemic threatened species in the region is Ballantinia antipoda or Southern Shephard’s Purse. Ballantinia is a tiny annual brassica, less than 5cm tall, with striking delicate white flowers. It has a very limited habitat range across the highest points of Leanganook (Mount Alexander).
Ballantinia was endemic to south-eastern Australia, being found through parts of Victoria and Tasmania. Around the 1800s, it started disappearing and was presumed extinct for most of the 20th century until it was rediscovered at Leanganook (Mount Alexander) in 1983. With much of the wider environment heavily modified for development and agriculture and invaded by weeds, the plant found refuge by growing in delicate moss mats on granite outcrops on the mountain. Surveys across the species’ historic range have failed to locate Ballantinia at other sites, and so it is believed that the only surviving population of the species is on Leanganook (Mount Alexander). Accordingly, its status is extinct in Tasmania, and critically endangered in Victoria.
In order to continue to preserve the species, annual surveys are undertaken to locate these refuges and note their condition, including current threats. In late August 2023 volunteers from across the Mount Alexander region joined Department of Energy, Environment and Climate Action’s Natural Environment Programs Officer, Aaron Grinter, to survey for Ballantinia across Leanganook (Mount Alexander).
Aaron reported that” the survey was attended by 15+ volunteers including Harcourt Valley Landcare and Metcalfe and Sutton Grange Landcare groups, as well as Parks Victoria field staff, Threatened Species Conservancy, Bendigo TAFE, Royal Botanic Gardens Victoria, and Connecting Country. All recently recorded population patches were surveyed except 1 due to time constraints. The plant was absent in 3 of the 8 remaining areas, and, where it was found, it was in significantly reduced numbers. One of the most important sites in particular that has previously recorded more than 1000 plants, only recorded 65. While climatic variation between warmer and cooler seasons is expected, a warming climate poses a significant threat to the species.
As Ballantinia is a cool climate annual, it germinates at 14 degrees Celsius, so we speculate that because of this warm, short winter, it hasn’t has the opportunity to fully sprout, which means the seed bank is not being sufficiently replenished. Royal Botanic Gardens Victoria have collected seed from the Ballantinia population in the past and have successful grown plants in a controlled environment. They will be returning next month to collect seed to bolster diversity in the population they have grown at the Royal Botanic Gardens.”
Thank you to Aaron Grinter, Natural Environment Program Officer at DEECA for the information and photos for this article.