About the talk
Australia’s forests span some of the world’s strongest gradients in climate variability and disturbance regimes, making the continent a natural laboratory for examining whether background tree mortality is shifting under climate change. In this seminar, I will present results from a collaboration with Australian researchers using an 83-year dataset (1941–2023) from more than 2,700 forest plots across Australia. Spanning tropical savannas and rainforests as well as warm and cool temperate forests, this dataset provides a unique opportunity to assess large-scale changes in forest mortality. Our analysis reveals a pervasive increase in background tree mortality across all four major forest biomes. These trends persist after accounting for stand structure and recovery dynamics and are most consistently associated with rising temperatures, with additional influences from drought, atmospheric water demand, and cyclones in tropical forests. Although species traits explain differences in baseline mortality among species, they do not prevent the widespread increase observed over time. Our continent-wide assessment suggests that rising temperatures are already shifting the demographic balance of Australian forests, with important consequences for their long-term capacity to store carbon.