Fast-growing trees are at risk of dying younger and releasing carbon dioxide, which challenges predictions that forests will become “sinks” for global warming emissions, scientists said Tuesday.
Wood cover absorbs a significant portion of the carbon dioxide emitted when burning fossil fuels, and plays an important role in predicting its ability to lower CO2 levels.
Researchers predict that the current climate model predicts that forests will continue to serve as carbon sinks through this century, and high temperatures and concentrations of CO2 promote tree growth and help them absorb more carbon as they mature faster.
However, a study led by the University of Leeds in the UK and published in the journal Nature Communication, They warned that this rapid growth has to do with trees dying because they are younger. This suggests that the role of forests increases because carbon storage can be “short-lived”.
The researchers looked at records of more than 200,000 tree rings in tree species around the world and found that a trade-off between growth and longevity occurred in almost all trees, including tropical trees.
Society has benefited from the increased ability of forests to absorb carbon in recent decades, said co-author Steve Voelker of the New York State University School of Environmental Sciences and Forestry in a statement at the University of Leeds.
However, these rates of CO2 uptake are likely to decrease as “slow-growing persistent trees grow rapidly but are replaced by vulnerable trees”, He added.
“Much like the story of turtles and rabbits, our research shows that the fastest-growing trees have properties that make them vulnerable, while the slow-growing trees have properties that can last.” He said.
The researchers said the findings dramatically increase the likelihood of dying as the tree reaches its maximum potential size.
However, they said fast-growing trees may invest less in defenses against disease or insect attack, or may be more susceptible to drought.
Earth’s average surface temperature has risen more than one degree Celsius above pre-industrial levels, and has risen enough to increase the severity of more devastating droughts, heat waves and super storms due to sea rise.
Sink or source?
Regarding the study, David Lee, professor of atmospheric science at the University of Manchester Metropolitan University in the UK, said that the Earth System Climate Model predicts that the current forest’s carbon storage will continue or increase.
“This study, on the contrary, shows that increased carbon dioxide damages forests as a carbon sink,” he said.
It added that the idea that “fossil fuel-based emissions can be offset by planting trees (or avoiding deforestation)” does not really fit scientific investigation.
But Keith Kirby, a forest ecologist at Oxford University, said forests don’t need to reverse the carbon role.
“We cannot rely heavily on increased growth per unit area to maintain and enhance forest carbon uptake potential, but this could be offset by slowing deforestation and increasing the extent of deforestation that this could be done in a sustainable way. .” He said.
The global warming-causing CO2 is absorbed by global forests, especially tropical regions, which erupt 25 to 30% of humanity into the atmosphere.
Last year, a football stadium of primary high-growth trees was destroyed every 6 seconds, according to a total of about 38,000 square kilometers (14,500 square miles). Global forest monitoring.
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