TREES across Australia\u2019s forests are dying at increasing rates as the climate warms, according to a major new study led by Western Sydney University.<\/p>\n
The research found a continent-wide rise in background tree mortality, defined as tree loss not caused by fire, clearing or logging.<\/p>\n
Published in Nature Plants, the study analysed 83 years of data from more than 2,700 forest plots across Australia.<\/p>\n
The plots span a range of forest ecosystems, including tropical rainforests, savannas and temperate eucalypt forests.<\/p>\n
Researchers found background tree mortality has increased steadily since the 1940s across all forest types.<\/p>\n
Over the same period, tree growth has remained the same or slowed, indicating the trend is not part of a natural cycle of renewal.<\/p>\n
The study found the rise in tree deaths closely tracks Australia\u2019s warming and drying climate.<\/p>\n
Rising temperatures were identified as the dominant driver of increased mortality.<\/p>\n
Tree deaths increased most rapidly in hot, dry regions and in dense forests where competition for water and light intensifies stress.<\/p>\n
Senior author Distinguished Professor Belinda Medlyn from Western Sydney University\u2019s Hawkesbury Institute for the Environment said the findings pointed to growing pressure on Australia\u2019s forests.<\/p>\n
\u201cAustralians rely on their forests for a wide range of ecosystem services, from cultural values and recreation to timber for houses. Increasing tree mortality in our unique forests will affect all of these,\u201d Professor Medlyn said.<\/p>\n
\u201cA particular worry is that the forests\u2019 ability to store carbon will decline. This has significant implications for Australia\u2019s net carbon balance,\u201d she said.<\/p>\n
Professor Medlyn said forests worldwide currently absorb about one-third of human carbon dioxide emissions.<\/p>\n
\u201cIf mortality continues to rise while growth stagnates, that buffering capacity will erode,\u201d she said.<\/p>\n
She said recent evidence from northern Australia showed tropical rainforests shifting from being net absorbers of carbon to net producers.<\/p>\n
\u201cThis will weaken the planet\u2019s ability to absorb emissions and amplify existing climate feedbacks, further narrowing the window for stabilising the global climate,\u201d she said.<\/p>\n
The study found the combined trend of rising mortality and stagnant growth signals a decline in the resilience of Australian forests.<\/p>\n
Researchers said adapting forest management could help safeguard forest health but warned that monitoring capacity has declined.<\/p>\n
The study found the number of long-term forest monitoring plots has fallen sharply over the past 25 years.<\/p>\n
\u201cOur 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,\u201d Professor Medlyn said.<\/p>\n","protected":false},"excerpt":{"rendered":"
TREES across Australia\u2019s forests are dying at increasing rates as the climate warms, according to a major new study led by Western Sydney University. The research found a continent-wide rise in background tree mortality, defined as tree loss not caused by fire, clearing or logging. Published in Nature Plants, the study analysed 83 years of […]<\/p>\n