Western Australia's jarrah forests were unevenly impacted by the record-breaking 2023-2024 heatwave and subsequent drought, with some areas experiencing more severe tree die-off than others, according to a new study.
PhD student Huanhuan Wang, from The University of Western Australia's Centre for Water and Spatial Science and School of Environmental Engineering, was lead author of the study published in Environmental Research Letters, which combined satellite observations with groundwater, soil and geophysical data.
Researchers examined how forests across the South West of Western Australia responded to 2024's extreme summer heat and drought and found that areas with shallow soils, rocky terrain and limited access to groundwater were most vulnerable.
"We found these areas showed much stronger declines in forest health than areas with deeper soils and better subsurface water availability," Ms Wang said.
"The results suggest forest vulnerability depends not only on extreme climate conditions, but also on what lies beneath the surface.
"Our study highlighted the critical role of soil depth, rockiness and groundwater access in shaping how forests respond to extreme heat and drought."
By integrating multiple data sources, the study identified spatial patterns of forest vulnerability that were not apparent from climate data alone.
In a recent review , co-author Professor Sally Thompson, from UWA's Centre for Water and Spatial Science and School of Engineering, outlined a framework for how ecosystems adapt to a drying climate.
"The jarrah forest study provided evidence for how the framework can be applied in practice, helping forest managers decide where to act — such as by thinning forest — and where to prioritise protection of forest areas that cope better with heat and drought," Professor Thompson said.
The research also demonstrated the value of combining remote sensing with hydrological understanding.
"By integrating satellite data with subsurface process knowledge, the study improves our ability to understand ecosystem vulnerability and support more targeted forest management strategies," Ms Wang said.
