Trees in tropical rainforests may be too hot to photosynthesize, according to a study reported March 15, 2020 in the Jurula River, Brazil./Florence Goisnard/AFP/Getty Images
2023.08.24 Thu posted at 18:00 JST
(CNN) A team of researchers from the United States, Australia, Brazil, and elsewhere in the rainforests of South America and Southeast Asia said on Monday that some leaves may be unable to perform photosynthesis due to excessive heat. published in the scientific journal Nature.
Photosynthesis, the process by which plant leaves produce energy from carbon dioxide, sunlight and water, begins to falter when temperatures reach around 46.7 degrees Celsius. Leaf temperature can be significantly higher than air temperature, the researchers said.
The research team used temperature data received from a thermal satellite sensor at the International Space Center, about 400 kilometers above the Earth. The observations were combined with data from sensors attached to leaves that climbed into the upper rainforest canopy.
They found that the average temperature in the canopy was 34 degrees Celsius at its peak, but exceeded 40 degrees Celsius in some areas.
At present, 0.01% of leaves are above the temperature at which photosynthesis ceases, and such leaves and trees can die.
According to reports, as global warming progresses, this proportion will increase, threatening the world’s rainforests. Tropical rainforests cover about 12% of the planet and are home to more than half of the world’s species. It also plays an important role in regulating the Earth’s climate by absorbing carbon dioxide.
Uganda rainforest
The researchers predict that rainforests can withstand up to about 4 degrees of global warming, but beyond that, their photosynthetic capacity will reach a breaking point. If warming exceeds this level, the proportion of leaves reaching temperatures at which photosynthesis cannot occur could increase to 1.4%, which could lead to mass leaf loss and whole tree death. It is pointed out.
Current climate change measures predict that temperatures will rise by 2.7 degrees Celsius above pre-industrial levels, and that much warming is not anticipated. However, the most pessimistic scenario of continuing to burn fossil fuels is expected to occur.
Experts say the findings and assessments show that climate change is jeopardizing this critical process, as nearly all organisms depend on photosynthesis for food, while others say the opposite. Some people
Given the scarcity of leaves reaching temperatures where photosynthesis ceases to function, and the magnitude of the warming required, the findings suggest that “theoretically, forests can It shows that we are quite resilient to climate change.” “It’s a simple model, forest dynamics are much more complex,” he added.
Despite the uncertainties, the study’s authors emphasize the significance of the study, which provides insight into how rainforests will respond to climate change. Co-author Joshua Fischer, a climate scientist at Chapman University in the United States, called the discovery “a reminder of the unknown dangers we’re starting to see.”
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2023-08-24 09:00:00
