Saturday , January 23 2021

Amazon forests fail to keep pace with climate change



Measurement of the growth of the Amazon tree in the forest land, Peru (2009) Credit: Roel Brienen, University of Leeds

A team of over 100 scientists evaluated the impact of global warming on thousands of tree species in the Amazon to discover winners and losers from 30 years of climate change. Their analysis found that the effects of climate change alter the composition of tropical rainforests in tree species, but not fast enough to keep up with the changing environment.


The team, led by the University of Leeds, in collaboration with more than 30 institutions around the world, used long-term records from more than one hundred lots as part of the Amazon Forest Inventory Network (RAINFOR) Amazon Region. Their findings have found that since the 1980s, the effects of global climate change – stronger droughts, elevated temperatures, and higher levels of carbon dioxide in the atmosphere – have slowed the growth of tree species and mortality.

In particular, the study found that tree-loving tree species are more dead than other species, and those adapted to the dry climate have failed to replace them.

Adriane Esquivel Muelbert, lead author of the Leeds Geography School, said: "The ecosystem's response is the rate of climate change. The data have shown us that droughts that have hit the Amazon basin in recent decades have had serious consequences for forest formation, with higher mortality in tree species most vulnerable to drought, and inadequate growth of better-equipped species to survive drier conditions. "

The Dead Forest in Amazon Central, Brazil, 2016 Credit: Adriane Esquivel Muelbert, University of Leeds

The team also found that older trees – predominantly canopy species in the higher levels of forests – are smaller than the smallest. The team's observations confirm the belief that the canopy species would be the "winners" of climate change, benefiting from the growth of carbon dioxide, which will allow them to grow faster. This also suggests that higher carbon dioxide concentrations also have a direct impact on the composition of tropical forests and the dynamics of forests – the way forests grow, die and change.

In addition, the study shows that pioneering tree trees that spring rapidly and grow in gaps left behind when trees die – benefit from accelerating forest dynamics.

Co-author of the study, Oliver Phillips, lecturer of tropical ecology in Leeds and founder of the RAINFOR Network, said: "The increase in the number of pioneering trees, such as extremely fast Cecropia, is in line with the changes observed in forest dynamics, the latter being determined by the increase in carbon dioxide. "

Measurement of large trees in Amazon Central, Brazil, 2016 Credit: Adriane Esquivel Muelbert, University of Leeds

Co-author Dr. Kyle Dexter of the University of Edinburgh said: "The impact of climate change on forest communities has important consequences on the biodiversity of tropical rainforests. The most vulnerable species are doubled at risk, limited to fewer locations the heart of the Amazon, which makes them more likely to disappear if this process continues.

"Our findings highlight the need for stringent measures to protect intact tropical forests. Deforestation for agriculture and animals is known to increase the drought in this region, exacerbating the effects already caused by global climate change."

The paper responds to the Amazon's climate change behavior Global Change Biology November 8, 2018.


Continue to explore:
Drought increases tree growth and closes Amazon carbon sink, researchers found

More information:
The compositional response of the Amazon forests to climate change, Global Change Biology, DOI: 10.1111 / gcb.14413

Journal reference:
Global Change Biology

Provided by:
University of Leeds


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