Australia's Forests Dying Faster as Climate Warms

A major new study has revealed forests across Australia are losing trees at accelerating rates, signalling a continent-wide shift in vegetation driven by a rapidly warming climate.

New James Cook University-supported research, led by Western Sydney University, analysed 83 years of data from more than 2,700 forest plots nationwide. The study provides the first comprehensive synthesis of background tree mortality — tree loss not caused by fire, logging or land clearing — across Australia’s diverse forest ecosystems, including tropical rainforests, savannas and temperate eucalypt forests.

JCU Associate Professor Michael Liddell was a co-author on the research and contributed tropical rainforest data. The findings show a persistent rise in background tree mortality since the 1940s, with the trend strikingly consistent across all forest types.

Over the same period, tree growth has remained static or slowed, indicating the increase in mortality is not part of a natural regeneration cycle but evidence of a growing imbalance between tree growth and loss.

Assoc Prof Liddell said the research highlighted the importance of long-term forest monitoring.

“As climate change reshapes the questions we ask of forest systems, long-term datasets are becoming increasingly important for answering them with confidence,” he said.

“We know tree mortality will have flow-on effects, so we need to track carbon fluxes, and faunal biodiversity to better understand how ecosystems are responding to a rapidly warming climate.”

The study found tree mortality is increasing fastest in hot, dry regions and dense forests where competition for water and light intensifies stress.

Senior author Distinguished Professor Belinda Medlyn warned rising mortality threatens forests’ ability to store carbon.

“Increasing tree mortality in our unique forests will affect all of these,” she said.

“Our results highlight the critical need for ongoing forest monitoring that is designed to detect long-term trends, in order to guide effective forest management for the future.”

‍