Australian Institute of Botanical Science researchers in partnership with South32 Illawarra Metallurgical Coal have successfully restored an endangered plant population on a mining site as part of a wider project to develop protocols for the future conservation of threatened plants.
In a new paper in Restoration Ecology, scientists report on the results of the first experimental translocation trial of Persoonia hirsuta or hairy geebung, an endangered shrub related to the well-known waratah and banksia plants that is patchily distributed across the Greater Sydney region of NSW in dry sclerophyll woodlands.
Lead researcher Samantha Andres, a PhD researcher with the Institute and Western Sydney University, said many native populations of this species consisted of a few plants or a single isolated individual.
“Sadly, there has also been significant population decline in recent years and some populations of the species have become locally extinct,” she said.
“To mitigate the risk of this species extinction, we translocated 128 plants to a site owned and operated by South32 Illawarra Metallurgical Coal near Appin, which is a key management and conservation area for Australian Coal Industry's Research Program.
“The research is focussed on maintaining and enhancing the remnant hairy geebung population on offset and rehabilitation areas on mining lease.”
South32 Illawarra Metallurgical Coal is working with the Institute to improve the capacity to conserve threatened plants on mining lease.
“Increasing development and urbanisation in Greater Sydney has posed a significant threat to many plant species and translocation is commonly used in the conservation of threatened species to prevent the risk of local extinctions by supplementing small or declining populations with additional plants to improve seed production and recruitment,” Andres said.
“The problem with doing this is there is often limited knowledge of the species biology and its ecological requirements to succeed in the landscape.
“Trials like this can help to address species knowledge gaps and identify effective strategies for the successful establishment of a threatened species prior to implementing full-scale planting regimes.”
Severe temperatures and drought conditions over the summer of 2019-2020 impacted the planting trial with 25 of the 128 plants surviving after two years.
However, the experiment successfully identified several key factors that should be considered for the ongoing management of the species, including the use of plant guards and local mulch to reduce the effects of herbivory and drought. The research also determined that plants grown from seeds outperformed plants grown from vegetative cuttings.
In a separate paper published in the Australian Journal of Botany, the Institute has also reported the reproductive biology of the endangered shrub with the results to assist with the planning of future translocations for this species.
Dr Nathan Emery and Dr Cathy Offord surveyed bee pollinators of the hairy geebung and performed experimental pollination treatments to understand the plant’s breeding system.
The researchers discovered the species was almost exclusively visited by native bees, and greater numbers of fruits were produced when flowers were pollinated from a neighbouring plant than from self-pollination.
“This information is critical for future conservation management of the hairy geebung as small and isolated populations are less likely to produce fruits and may continue to decline unless supplemented with additional plants via translocation,” Dr Emery said.
Scientists at the Institute are also working on a wide range of projects aimed at greening the urban environment sustainably, ensuring resilient ecosystems and much more.
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