Extreme temperatures and humidity levels (excessive rain or drought) projected for the Amazon in the context of climate change may increase the volume of methane-producing microorganisms in flooded areas and reduce potential uptake of this greenhouse gas in upland forests by 70%, with global impacts, according to a study conducted by researchers at the University of São Paulo (USP) in Brazil. An article reporting their findings is published in the journal Environmental Microbiome.
Extreme temperatures and humidity levels (excessive rain or drought) projected for the Amazon in the context of climate change may increase the volume of methane-producing microorganisms in flooded areas and reduce potential uptake of this greenhouse gas in upland forests by 70%, with global impacts, according to a study conducted by researchers at the University of São Paulo (USP) in Brazil. An article reporting their findings is published in the journal Environmental Microbiome. Effective conservation and management policies are all the more important in light of the results, the researchers said.
For at least six months every year, more than 800,000 square kilometers of floodplains in the Amazon Rainforest, equivalent to 20% of its total area, remain under several meters of water as a result of steady rainfall and rising levels of the region’s rivers. Methane production increases as microbial communities break down organic matter. Recent studies show that floodplains in the Amazon contribute up to 29% of global wetland methane emissions. On the other hand, the region’s upland forests act as methane sinks, capturing the gas from the atmosphere and playing an important role in the regulation of greenhouse gas emissions.
“Although it’s already been shown that factors such as air temperature and seasonal flooding can influence the composition of microbial communities and hence affect the flow of methane in these environments, what should we expect in the context of climate change and the projected alterations in rainfall and temperature patterns, with more intense extremes?” said Júlia Brandão Gontijo, first author of the article and currently a postdoctoral researcher at the University of California, Davis in the United States.
Read more at: Fundação de Amparo à Pesquisa do Estado de São Paulo
Amazon River water levels in the rainy season (left) and dry season near Santarém, Pará state, Brazil (Photo Credit: Júlia B. Gontijo)
