A new research has found that in addition to the Amazon rainforest in Brazil, the phenomenon of trees live fast and die young as it happens in the warm climatic regions happens across all latitudes.
And according to the new research, this trend can spell bad news for tackling the global climate crisis.
Warmer conditions make trees grow faster and that is supposed to be a natural brake on global heating since such trees take in and store more carbon dioxide from the air with the trees growing. But doubts about that beneficial cycle are raised by the new study which finds that if trees grow faster they die faster and the earlier tree die, the beneficial effect for the climate is reduced.
For long, shorter life spans are expected for long for some fast-growing trees in the cold regions which include conifer species. But the new study has revealed the impact of warmer conditions that can increase growth rate of trees with the accelerating of global heating.
The relationship between faster growth and shorter lifespan of tress is apparently also exists across tree species and latitudes, found a study conducted by an international team of researchers whose work was published on Tuesday in the peer-review journal Nature Communications.
“We started a global analysis and were surprised to find that these trade-offs are incredibly common. It occurred in almost all species we looked at, including tropical trees,” said Roel Brienen, associate professor of geography at the University of Leeds, the lead author of the paper.
The chance of trees dying faster in warmer conditions is because they reach their maximum size sooner than in colder conditions. With respect to events like drought, disease and pests, those species of trees that grow more quickly may also be more vulnerable. After the death of a tree, the carbon dioxide stored in them is gradually give up in the form of methane which is a greenhouse gas.
This study therefore put to question a lot of the standard climate change models that see the possibility of reducing carbon presence in the atmosphere by forests and trees as trees absorb carbon dioxide. But trees of the future that could grow faster with increasing temperatures could also be able to store less carbon as they also die off sooner, the new study suggests.
“Our findings indicate that there are traits within the fastest-growing trees that make them vulnerable, whereas slower-growing trees have traits that allow them to persist,” said Steve Voelker of the department of environmental and forest biology at Syracuse University New York, a co-author of the study. “[The] carbon uptake rates of forests are likely to be on the wane as slow-growing and persistent trees are supplanted by fast-growing but vulnerable trees.”
“Currently, Earth system climate models predict continuation or increases in the size of the carbon sink of mature forests and this study shows the opposite, that increased CO2 compromises forests as a carbon sink … The idea that fossil fuel-based emissions can be offset by planting trees or avoiding deforestation really does not stand up to scientific scrutiny,” said David Lee, professor of atmospheric science at Manchester Metropolitan University, who was not involved in the study.
(Adapted from TheGuardian.com)