Vegetation Assessment Using Remote Sensing: A Systematic Review for Eucalypts in Australia

Rapid advancements in remote sensing increasingly allow assessing vegetation at the landscape, local and individual scales. This systematic review investigates the diverse applications of remote sensing for assessing vegetation in eucalypt forests and woodlands within Australia. Of the 137 studies included in the review, two-thirds investigated vegetation conditions, including the effects of dieback and fire, with the remaining articles focusing on vegetation classification and structural vegetation properties. This focus on vegetation conditions highlights the potential of remote sensing to contribute to the monitoring and conservation of biodiversity, suggesting that remote sensing will become more important as the impacts of climate change intensify. Currently, the application of remote sensing methods for investigating eucalypt vegetation remains underutilised. For example, remote regions, including areas of high biodiversity, are generally poorly studied, highlighting major gaps in spatial coverage. Furthermore, study locations are often reported in insufficient detail to facilitate independent verification and reproducibility, reducing the usefulness of existing studies. A key challenge in remote sensing is the identification of an appropriate approach based on the research question and the resources available and we provide guidance with that. Reviewed studies predominantly used freely available imagery (e.g., Landsat and Sentinel), whilst high-resolution commercial imagery (e.g., WorldView) and research-accessible datasets (e.g., PlanetScope) remain little utilised. Emerging technologies like LiDAR, UAVs and hyperspectral imaging that could provide insights at higher resolutions require greater resources for data collection and processing and are yet to be widely integrated into vegetation assessment. To address these challenges, interdisciplinary collaboration among vegetation and remote sensing specialists, and a framework for selecting appropriate remote sensing methods based on research and resources, are critical. Such efforts would help align study objectives with appropriate tools and resources and will be crucial to achieving biodiversity and climate adaptation goals in Australia and beyond.