Tree mortality has increased across the Australian continent, researchers report

Researchers analysed 2,724 long-term forest plots across Australia (1941–2023) and report a widespread increase in tree mortality; they note that carbon accounting models and a decline in long-term monitoring may misrepresent forest carbon dynamics.

Researchers report a widespread rise in tree mortality across the Australian continent. They compiled and analysed data from 2,724 long-term forest monitoring plots spanning 1941–2023. The finding is discussed in the context of forest management and national carbon payment schemes. The authors note that incomplete and declining monitoring data complicate estimates of forest carbon storage. Key facts: - Dataset: 2,724 plots from 12 long-term monitoring networks across Australia, with censuses spanning 1941–2023. - Reported trend: a pervasive increase in tree mortality observed across multiple biomes. - Policy implication: the authors report that ecosystem models that do not simulate increasing tree mortality rates may overestimate forest carbon sink strength, with potential consequences for carbon accounting programmes. - Monitoring gap: long-term plot coverage has declined since the early 2000s for reasons including land-tenure changes, funding and institutional restructuring, adoption of airborne remote sensing, and losses from wildfires; the authors report a cumulative loss of 187 plot-census records since 2000 and 404 in total. Summary: The authors report that rising tree mortality and gaps in long-term monitoring can bias estimates of forest carbon dynamics that underpin carbon payment and accounting programmes. They advocate for the continuous maintenance of permanent plots and for establishing a spatially representative monitoring network to support more reliable cross-biome comparisons and ecological forecasts.