Spread the love

Post Views: 34

A new study by 80 scientists from Europe and South America has identified the regions of the Amazon rainforest most likely to face the most significant risk from drier conditions caused by climate change. The study, which provides the first assessment of how different areas of the Amazon Forest are likely to respond to a warmer and drier climate, warns that trees in the western and southern Amazon face the most significant risk of dying.

The study reveals that previous scientific investigations may have underestimated the impact of drought on the rainforest because they focused on the central-eastern part of the forest, which is the least vulnerable to drought. The findings are significant because some studies predict the rainforest will experience increased periods of drought.

Dr Adriane Esquivel Muelbert at the Birmingham Institute of Forest Research (University of Birmingham), who contributed to the study, said, “This work fills a fundamental gap in our understanding of how tropical trees are responding to droughts, and how they will respond to droughts in the future.”

The research team, known as the “tree doctors” to the communities living in the forest, took measurements and samples over a year from 11 separate sites across the western, central-eastern, and southern Amazon – covering Brazil, Peru, and Bolivia. The study involved data from 540 individual trees across 129 species. The researchers wanted to determine how resistant different tree species and forests were to drought conditions.

The scientists used the data to test whether forest vulnerability to drought could predict its ability to accumulate and store carbon from the atmosphere. The research team could quantify how safe the trees were from drought-related death from the data.

In the southern part of the Amazon Forest, where historically there have been declining levels of rainfall, the trees showed the most significant degree of adaptation to cope with drought. Despite that, the study revealed that the trees faced the most significant risk of dying due to drought. This is likely because the region has already seen rapid climate change and disruption to rainfall patterns caused by deforestation, pushing trees to the limits of their ability to cope.

The study’s lead author, Dr Julia Tavares, who is now based at Uppsala University in Sweden, said, “A lot of people think of the Amazon as one large forest. But it is not. It is made up of numerous forest regions that span different climate zones, from locations that are already very dry to those that are extremely wet, and we wanted to see how these different forest ecosystems are coping so we could begin to identify regions that are at particular risk of drought and drier conditions.”

Professor David Galbraith, from the University of Leeds, who supervised the study, said, “Multiple stressors, including deforestation and climate threaten the Amazon. Understanding the stress limits that these forests can withstand is a major scientific challenge. Our study provides new insights into the limits of forest resistance to one major stressor – drought.”

The study’s findings are published in Nature’s scientific journal titled “Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests.” The researchers hope their findings will help policymakers and governments identify and protect the most vulnerable areas of the Amazon Rainforest.