RSSA March 2025 Meeting and Scientific Presentation

We are very excited to invite you all to the first RSSA Meeting and Scientific Presentation of 2025!

We will be kicking off an exciting year on March 13th, with scientific presentations from two special guest speakers. Join us as we dive into exciting research on Australian and New Guinea Water Beetles and hear about novel efforts to safeguard stringybark eucalypts in the face of changing climates. 

The event will begin at 6:00 pm with nibbles, refreshments and opportunities for pre-meeting discussions and networking. A small donation to the RSSA is greatly appreciated to partake in this and support the continued provision of these pre-meeting treats.

This event will be held in-person in the Royal Society rooms, but we will simultaneously live-stream the meeting via Zoom for those not able to attend on the night.

To attend either in person, or online, you must register here. The zoom link will be sent to you on registration. Please feel free to share this event with your institution or networks.

If in-person tickets are sold out, please be aware that we are unable to admit more people than our room capacity. If online tickets are sold out, please contact admin@rssa.org.au and we can supply the zoom link to you.

For more information on the location of the RSSA rooms, please visit https://www.rssa.org.au/contact/

Yuxuan Zhao (George)

Talk Title: “From Ground to Below and Pinnacle: Tempo and Mode of morphological evolution in Australian and New Guinea Water Beetles (Dytiscidae)”

Bio: Yuxuan Zhao (George) is a second-year PhD student at the University of Adelaide. His PhD research delves into the evolutionary history of Australian water beetles (Dytiscidae), constituting both subterranean and surface species. He is using a multi-disciplinary approach to explore the complex pathways shaping their evolution of this unique ecosystem.

Abstract: Ecological 'free space' alters selection pressures on organisms entering new environments. While phenotypic evolution is often attributed to directional selection, we present evidence for alternative pathways. Over the past ~10 million years, Australian and New Guinean dytiscid beetles have colonised surface, alpine, and subterranean aquatic habitats, serving as "evolutionary experiments" that trace transitions from surface life to extreme environments. We investigated body shape evolution as species occupied new niches, focusing on potential selection and relaxed selection among three eco-types of water beetles. Using a phylogenetic-comparative approach, we analysed the body shape morphology of species within the dytiscid genus Limbodessus. Our findings reveal that surface-dwelling dytiscids exhibit convergent evolutionary stasis, indicating strong selection pressure on body shape. Subterranean species have undergone directionless morphological radiation, suggesting reduced selection pressure. Alpine dytiscids show directional morphological radiation, highlighting strong selection pressures driving divergence in this extreme habitat.

Chloe Bentze

Talk Title: “Using in-situ microrefugia to safeguard stringybark eucalypts in the face of climate change-type droughts”

Bio: Currently a PhD researcher at the University of South Australia, I am passionate about all things ecology and ecosystem conservation. After specialising in Ecology and Conservation in my undergraduate and master’s degrees at University College London and Imperial College London, I fled the cold and rain to undertake research here in Adelaide on stringybark eucalypt declines. I am in my last year of PhD, and keen to continue researching the future of forest ecosystems under unprecedented change. I am particularly interested in linking research with on-the-ground conservation action and translating research outcomes for informed landscape management.

Abstract: Facilitating species persistence under climate change is a pressing issue. Refugia, places where the impacts of climate change are less severe, may constitute the only option for ­in-situ persistence for many taxa. However, refugia will still experience some impacts of climate change and are vulnerable to other disturbances. Management approaches that utilize the buffering provided by climate-change refugia, whilst recognising their vulnerability, are needed. We established a gradient from good (putative microrefugia) to poor canopy health for a unique population of Eucalyptus macrorhyncha in South Australia. Microrefugia were located on pole-facing slopes and in valleys that received less solar radiation and were cooler and moister than other habitats. Physiological measurements (Percent Loss of Conductivity) indicate that microrefugia are already impacted by water stress during droughts. However, trees in microrefugia experienced lower drought stress than other habitats such as ridges and equator-facing slopes, and strong regeneration was observed in habitats with canopy dieback between 25-70%. These results suggest that persistence and recovery of populations in-situ should be feasible but may require interventions during periods of acute stress. Watering of targeted microrefugia and selected adjacent areas of high regeneration during extreme heatwaves in episodes of intense droughts could prevent the accumulation of hydraulic damage that triggers canopy defoliation and maintain a buffer around selected microrefugia.