The Amazon rainforest, often referred to as the lungs of the Earth, faces unprecedented changes from climate impacts and deforestation. Scientists have discovered that commercial logging and forest fires are erasing the ancient evolutionary history within our forests. As a result of these diverse disruptions, tree diversity is suffering a catastrophic drop off. This alarming trend has been documented in a recent study co-led by Dr. Erika Berenguer and Dr. Cássio Alencar Nunes, which assessed the impacts of human modifications on Amazonian tree diversity.
The new research published in the journal Global Change Biology exposes the dangerous effects of significant disturbances such as logging and wildfires. Illegal logging and recycling-related activities have done significant damage to the forest in recent years. Specifically, the Amazon suffered catastrophic fires in 2015 and recently in 2023. This photo taken in early 2024 tells that story of a changed landscape much more clearly. It draws attention to the long term impacts of the 2023 fire.
The Study’s Findings
Dr. Berenguer is a Brazilian-born researcher based at the Lancaster University and Environmental Change Institute at the University of Oxford. Together with Dr. Nunes, who is based at Lancaster University and the Universidade Federal de Lavras in Brazil, they carried out a detailed census of more than 55,000 trees large and small over 215 plots in two study areas of Eastern Amazonia. Their findings reveal a concerning trend: human disturbances are leading to an impoverished tree diversity within the forest ecosystem.
“Given that disturbed forests presented impoverished and distinct tree compositions, it is expected that large areas of the Amazon are already unable to provide the full range of ecosystem services found in undisturbed primary forests.” – phys.org
Researchers found that both disturbed primary forests and secondary forests supported fewer tree species. They further documented a negative impact on evolutionary lineages and functional types of trees, as compared to reference areas with minimal disturbance. Dr. Nunes noted that the disturbances reduced species richness by half. The bill removed protections for the keystone trees often found in these forests.
“However, it wasn’t just the numbers that were lower, but also the identity of the species, lineages and functional types changed after disturbance,” said Dr. Nunes. “Disturbance is not only resulting in impoverished tree diversity, it is changing the species composition of human-modified Amazonian forests.”
The idea behind this transformative change was to have more initial coverage with ‘pioneer’ tree species. At the same time, larger and slower-growing species abandoned the disturbed areas. Dr. Nunes spoke to the importance of this shift, saying that it’s a reflection of the larger changes going on in nature as humans have an impact.
The Importance of Biodiversity Conservation
Dr. Berenguer emphasized connecting climate conversations with biodiversity protection to combat both crises simultaneously. She emphasized the need to protect intact forests. These logged forests are important for climate-stabilizing carbon they continue to sequester as well as for safeguarding the evolutionary history that has developed into one of Earth’s most biodiverse ecosystems.
“As the Amazon faces mounting human pressures, conserving remaining undisturbed forests is essential—not only for their carbon-storing potential but also to preserve the deep evolutionary heritage that has shaped one of our planet’s most diverse ecosystems.” – Dr. Erika Berenguer
The Amazon rainforest is home to the greatest number of tree species anywhere on Earth. Europe has just 450 native species and the UK only has 32. This unique biodiversity contributes to the production of critical ecosystem services like carbon sequestration.
Dr. Berenguer further noted that while recent advancements in understanding human impacts on rainforests are significant, they highlight a critical reality: “when it comes to understanding human influences on rainforests, it does not matter much—human influences are so profound that all measures are changing.”
Looking Ahead
As discussions around climate change intensify, particularly in forums like COP30, there is an urgent call to integrate biodiversity into these conversations. Dr. Berenguer pointed out that only considering the carbon aspect is not enough to tackle the climate and biodiversity crisis.
“Although the focus of COP30 is mostly on carbon, linking climate discussion with biodiversity is essential if we want to overcome the climate and biodiversity crisis,” she stated. “Ultimately, biodiversity is what guarantees the provision of ecosystem services such as carbon sequestering and stocking.”
Despite the negative effects of the pandemic on transit, this study provides a glimpse at a way forward. It accepts that disturbed forests are more valuable than regenerating clear-felled land. This perspective underscores the need for innovative protection mechanisms like the Tropical Forest Forever Facility (TFFF), which aims to fund conservation efforts for all forests—not just those that remain untouched by human influence.