A recent study published in the Proceedings of the National Academy of Sciences reveals that more than a third of the Amazon rainforest struggles to recover from drought, signaling a “critical slowing down” in its resilience.
This vital ecosystem, known as the world’s largest tropical forest and a crucial carbon sink, faces the risk of irreversible degradation.
The study’s findings emphasize the impact of repeated severe droughts, which have occurred at a frequency exceeding previous estimates.
These extreme weather events, exacerbated by human-induced climate change, place uncommon stress on the forest’s vegetation, leading to widespread dehydration and plant mortality.
Also read: Controversial practice of ‘avoided deforestation’ in Amazon raises concerns
Historically, the Amazon rainforest’s canopy would naturally adapt to seasonal variations between wet and dry periods. However, the frequency and severity of recent droughts have disrupted this equilibrium, posing significant challenges to the forest’s recovery.
Researchers analyzed satellite imagery of vegetation activity from 2001 to 2019 in the study. They examined tens of thousands of pixels, each covering a 25-square-kilometer area, monthly and compared them with local rainfall data.
The study aimed to understand “the frequency, intensity, or duration of droughts contributes to stability loss of Amazon vegetation.”
The findings revealed that 37% of mature vegetation in the region displayed a slowing-down trend.
While these patterns varied across different areas, the researchers identified the highly deforested and degraded southeastern Amazon as the most susceptible to a “tipping event” — a catastrophic transition of the tropical rainforest into a drier state.
The paper’s lead author, Johanna Van Passel, said, “Trees are the last part of the ecosystem to show tipping points because they have the longest life cycle and are most able to cope.”
“If we are already seeing a tipping point getting closer at this macro forest level, then it must be getting worse at a micro level.”