Author: Penny Paton
Over two mornings in the Rare Plant Garden, the Friends Group achieved a world first. Overseen by plant experts from KI and from SA’s Seed Conservation Centre (SASCC), volunteers planted over one thousand rare and endemic plants for nearly 50 species. The endemic plants grow nowhere else on the planet and some of the rare plants are known from only a few small populations, often on roadsides. By planting them into the Garden, where seed can be collected for long-term storage and for growing on more plants, their populations can be protected and enhanced.
The planting days on 7 and 8 July 2023 saw volunteers putting in species that have never been planted before and, for some, they were grown from seed that has never been collected or propagated before. Dan Duval, of the SASCC, said: “It was a very exciting day for plant conservation on the island. We have demonstrated the methods for recovering these species and shown the steps required for reintroducing these rare plants into new areas on the Island”.
Some of the species that have never been grown or planted before are Acrotriche halmaturina, Hibbertia glebosa var. oblonga, Logania scabrella, Spyridium scabradum, Dampiera lanceolata var. insularis and Hibbertia obtusibracteata. On top of this we have also supplemented last year’s plantings of several endangered species, like Astrolasia phebalioides, Gahnia hystrix, Beyeria subtecta and Leionema equestre.
Seed of these threatened plants has been collected from remnant populations on Kangaroo Island, mainly after the devastating fires of 2020, and also withdrawn from long-term storage at the Adelaide Botanic Gardens. Part of the recovery work for these plants involves developing protocols for germination and nursery propagation, so that the collections in long term storage at the Adelaide Botanic Gardens can be more effectively used for recovery work in the future.
When collecting seeds from the small remnant populations in a fragmented landscape, scientists from the SASCC sample as many populations as possible to represent the full range of the remaining genetic diversity. This ensures that the plants we put into the RPG are genetically robust to enhance the resilience of new populations established in future restoration programs.
The plantings this week were the next step in the collaboration between Bio·R, SASCC and the Nature Conservation Society of South Australia. Last year’s plantings have survived well and are growing healthily and we will be able to collect seed from many of these 60 species over the coming spring and summer. The next stage of the project will involve a landscape plan to direct the establishment of new beds, a gazebo, an ephemeral creek, signage and interpretation, new ponds and a seasonal wetland.