Tree cover absorbs a significant proportion of the carbon dioxide emitted from burning fossil fuels and plays an important role in estimates for our ability to reduce CO2 levels.
Researchers said that current climate models expect forests to continue to function as carbon sinks in this century, with higher temperatures and concentrations of CO2 helping to encourage tree growth and therefore maturing Help absorb more carbon.
But in the study, led by the University of Leeds, England and published in the magazine Nature communication, He warned that this rapid growth was also linked to younger trees – suggesting an increase in the role of forests because carbon storage may be “short-lived”.
Researchers examined more than 200,000 tree-ring records from tree species worldwide and found that trade-offs between growth and lifespan occurred in almost all, including tropical trees.
In recent decades, society has benefited from the increased ability of forests to absorb carbon, co-author Steve Volker of the State University of New York College of Environmental Science and Forestry said in a statement from Leeds University.
He said that these CO2 rates are likely to increase as slow-growing and continuously-growing trees are suppressed by fast-growing but weak trees. ”
“Our findings, much like the turtle and rabbit story, indicate that the fastest growing trees have traits within them that make them vulnerable, while slow-growing trees have traits that keep them in place. Allow, ”he said.
The researchers said the findings show that the probability of dying increases dramatically as trees reach their maximum possible size.
But he said that it may also happen that fast-growing trees invest less in protection against diseases or pests attacks, or are vulnerable to drought.
Earth’s average surface temperature has risen just one degree Celsius above pre-industrial levels, enough to increase the severity of droughts, heat and superstorms by rising seas.
Sync or Source?
Commenting on the study, David Lee, professor of atmospheric science at Manchester Metropolitan University in England, said climate models of the Earth system currently predict forests to continue or increase carbon storage.
He said, “This study shows the opposite that CO2 is increased in the form of carbon dioxide.”
This suggests that “fossil-fuel-based emissions may be ‘offset’ by deforestation (or refraining from deforestation) does not really stand up to scientific scrutiny”, he said.
But Keith Kirby, a woodland ecologist at the University of Oxford, said it was not necessary that forests would reverse their carbon role.
“We cannot rely too much on growth per unit area to maintain and increase forest carbon sink capacity, but it can slow deforestation and increase the extent of forest expansion where it is a sustainable Can be done in ways, ”she said.
Global forest – and especially tropical – planet-warming CO2 circulates in the atmosphere of 25 to 30 percent of humanity.
Last year, according to Global Forest Watch, a football pitch of primary, old-growth trees was destroyed every six seconds, about 38,000 square kilometers (14,500 square miles).
© Agnes France-Presse