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Some regions of the Amazon rainforest are more resilient to climate change than previously thought and may actually BENEFIT from warmer temperatures, according to a study.
- Researchers studied how changes in soil and air humidity affect photosynthesis
- Water stress was thought to have a largely negative impact
- This, in turn, would slow down the absorption of carbon by the Amazon and increase warming
- However, in more humid areas, dry air causes plants to grow leaves more efficiently
- The team warned, however, that excessive warming would also harm these areas
Warmer temperatures may benefit parts of the Amazon rainforest, suggesting that the tropical ecosystem may be more resilient to climate change than previously thought.
It was previously thought that water stress caused by global warming and the drying up of soil and air would greatly damage plants in the Amazon.
This would lead to a reduction in photosynthesis, the chemical process by which plants produce food and absorb carbon dioxide, and would help accelerate climate change.
However, US researchers found that the wetter areas of the world’s largest rainforest actually grow more photosynthetic-efficient leaves when exposed to dry air.
The team warned that there is a limit to this, however, and that excessively hot temperatures would continue to cause damage to even these hardy parts of the forest.
Warmer temperatures may benefit parts of the Amazon rainforest, pictured, suggesting the tropical ecosystem may be more resilient to climate change than previously thought.
“This is the first basin-level study that demonstrates that, contrary to what models show, photosynthesis is actually increasing in some of the very humid regions of the Amazon rainforest during limited water stress,” the author said. Pierre Gentine article.
‘This increase is related to atmospheric dryness in addition to radiation and can be largely explained by changes in the photosynthetic capacity of the canopy,’ added the environmental scientist from Columbia University in the United States.
“As trees get stressed, they generate more efficient leaves that can more than compensate for water stress.”
In their study, Dr. Gentine and colleagues used machine learning techniques to analyze data from various climate models to determine how changes in dry air and soil moisture in tropical regions of the Americas affect photosynthesis.
They compared these analyzes with those made of observational remote sensing data collected by satellites passing over rainforests.
Data from so-called flow towers, which monitor the exchange rates of carbon dioxide between the earth and the atmosphere around the world, were then used to study the processes at smaller scales.
The greenness of plants in parts of the Amazon basin at the end of the dry season had been observed in previous research.
“Prior to our study, it was still unclear whether these results translated into a wider region effect – and they had never been linked to dryness other than light,” added article author Julia Green. .
‘Our results indicate that current models overestimate the carbon losses in the Amazon rainforest due to climate change.’
‘In this particular region, these forests may indeed be able to sustain, or even increase, rates of photosynthesis with some warming and drying in the future.’
However, the team warned that if dryness increases beyond observed levels, photosynthesis could still slow down in the future.
‘We found a tipping point for the most severe drought stress episodes where the forest could not maintain its level of photosynthesis,’ said Dr. Green.
“So our results are certainly no excuse not to reduce our carbon emissions.”
Once their initial study is complete, the researchers are now looking to measure the impacts of water stress on plants’ carbon dioxide intake and relate it to specific ecosystem traits.
“Much of the scientific research coming out these days is that with climate change, our current ecosystems may not be able to survive, potentially leading to acceleration of global warming due to feedback,” reflected Dr. Green.
“It was nice to see that perhaps some of our estimates of approaching mortality in the Amazon rainforest may not be as disastrous as we previously thought.”
The full study results were published in the journal Science Advances.
WHICH SPECIES GROW IN THE RAIN FOREST TODAY?
Today, rainforests cover only about two percent of the earth.
However, about half of all plant and animal life exists in rainforests.
Rainforests exist on every continent except Antarctica.
Any four square mile area of the rainforest can host up to 1,500 flowering plants.
Researchers at the University of Birmingham found that climate change that occurred 307 million years ago affected the types of species living today. The shift caused the rainforests around the equator to dry out (photo file)
The same amount of space can accommodate 750 species of trees, 400 species of birds and 150 species of butterflies.
Resources such as timber, cocoa, coffee and some medicines come from the rainforests.
The National Cancer Institute of the United States said that 70 percent of plants useful in treating cancer grow exclusively in rainforests.
However, of all the many tropical rainforest species, less than 1% have been evaluated for their medicinal value.
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