PhD Candidate: Chaminda Alahakoon

PhD Supervisors: Associate Professor Paul Rymer (WSU), Associate Professor Rachael Nolan (WSU), Associate Professor Mark Ooi (UNSW), Dr Cathy Offord (Australian Plant Bank, BGS)

Project Summary: Australia is facing an extinction crisis driven by altered land-use and climate change. Although there is a large investment for ecosystem restoration, the outcomes are variable with failures in part due to climate change. It is unclear how to achieve climate resilient restoration outcomes - impeding Natural Capital accounting. Sourcing seed for restoration from future climate analogues has been advocated as an adaptive management strategy, however, this approach is yet to be tested against local versus diverse seed sources.

This project aims to predict which species in the iconic open grassy woodlands of eastern Australia are most vulnerable to climate change and where should seeds be sourced to enhance restoration success in future climates. The proposed research will focus on how temperature warming, and reduced rainfall impact the establishment of native seedlings in restoration-type, direct-seeded plots.

To simulate future warmer and drier conditions, an array of mini-rainout shelters combined with warming chambers on top of restoration plots are currently being established on the managed grassland adjacent to remnant grassy woodlands on the Western Sydney University, Hawkesbury campus. These structures will exclude natural rainfall and allow for controlled irrigation and air temperatures. We have sourced seed for a diverse array of 16 ground cover species found in grassy woodlands in the Sydney Basin, from local (Cumberland), warm (Hunter) and warm/dry (Kerrabee) regions. Seeds will be directly sown into 24 plots maintained under four treatments (control, dry, warm and warm + dry). Seedling emergence will be monitored over spring-summer, 2024 followed by sampling for plant traits in Autumn 2025.