Tuesday , February 7 2023

Amazonian forests that are not climate change


Forest parcel for measuring Amazon trees in Peru (2009). Credit: Roel Brienen, Leeds University

More than 100 scientists have evaluated the effects of global warming on thousands of Amazonian tree species to uncover winners and losers from 30 years of climate change. Their analysis revealed that the impact of climate change affects the composition of the tree species of rainforest, but not fast enough to keep pace with changing environments.

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 hundred plots of land under the Amazon Forest Inventory Network (RAINFOR) to track the lives of individual trees throughout the Amazon region. Their findings revealed that, since the 1980s, the effects of global environmental change – more severe droughts, increased temperatures and rising carbon dioxide levels in the atmosphere – slowly affected the growth and mortality of particular tree species.

In particular, the study found that most moisture-loving tree species dying more often than other species, and those that were fit for a dry climate could not replace them.

The holy author Dr. Adriane Esquivel Muelbert of the Leeds Geography School said: "The ecosystem reaction lags behind the pace of climate change. The data showed that the drought that hit the Amazon basin over the last decades had serious consequences for forest composition, higher mortality in tree species most affected subjected to drought and insufficient compensation for species that are better equipped to survive in colder conditions. "

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

The team also acknowledged that larger trees – mostly on the upper leaves of the foliage species – surpassed small plants. The group's observations confirm the belief that canopy species could become "winners" as they benefit from increased carbon dioxide, which allows them to grow faster. It also shows that higher concentrations of carbon dioxide also directly affect the composition of rainforest and the dynamics of forests – the way forests grow, die and change.

In addition, the study suggests that forestry dynamics accelerate the benefits of pioneer trees that grow rapidly and grow with spaces when trees die.

Research co-author Olivers Phillips, professor of ecology at Tedra in Leeds and founder of the RAINFOR network said: "The increase in the number of pioneering trees, such as the extremely fast growing Cecropia, is consistent with the observed changes in forest dynamics, which may eventually lead to increased levels of carbon dioxide."

Large Trees in Central Amazon, Brazil, 2016. Credit: Adriane Esquivel Muelbert, Leeds University

Shared author Dr. Kyle Dexter from the University of Edinburgh said: "The impacts of climate change on forest communities have a significant impact on the biodiversity of rainforests. The species most at risk of drought are threatened twice, as they are usually limited to smaller areas in the heart of the Amazon, most likely will disappear if this process continues.

"Our findings suggest the need for strong measures to protect existing rain-fed forests. It is known that agriculture and livestock deforestation are exacerbating the drought in the region, which exacerbates the effects already caused by global climate change."

The relative response of the Amazonian forest to climate change has been published Global Change Biology November 8, 2018.

Continue research:
Scientists are finding that drought is hampering tree growth and eliminating the Amazon carbon sink

More information:
Amazon forest composition response to climate change Global Change Biology, DOI: 10.1111 / gcb.14413

Reference to the journal:
Global Change Biology

Leeds University

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