Scientists Unravel How and Why Amazon Trees Die & Why Tree Mortality Is Increasing
The capacity of the Amazon forest to store carbon in a changing climate will ultimately be determined by how fast trees die – and what kills them. Now, a huge new study has unraveled what factors control tree mortality rates in Amazon forests and helps to explain why tree mortality is increasing across the Amazon basin.
This large analysis found that the mean growth rate of the tree species is the main risk factor behind Amazon tree death, with faster-growing trees dying off at a younger age. These findings have important consequences for our understanding of the future of these forests. Climate change tends to select fast-growing species. If the forests selected by climate change are more likely die younger, they will also store less carbon.
The study, co-led by the Universities of Leeds and Birmingham in collaboration with more than 100 scientists, is the first large scale analysis of the causes of tree death in the Amazon and uses long-term records gathered by the international RAINFOR network.
The results, published in Nature Communications, show that species-level growth rates are a key risk factor for tree mortality.
“Understanding the main drivers of tree death allows us to better predict and plan for future trends – but this is a huge undertaking as there are more than 15,000 different tree species in the Amazon,” said lead author Dr. Adriane Esquivel-Muelbert, of the Birmingham Institute for Forest Research.
Dr. David Galbraith, from the University of Leeds added “We found a strong tendency for faster-growing species to die more, meaning they have shorter life spans. While climate change has provided favorable conditions for these species, because they also die more quickly the carbon sequestration service provided by Amazon trees is declining.”