Scientists Advocate for Protection of Large Amazon Trees to Achieve Net-Zero Emissions

A recent study published in Frontiers in Forests and Global Change highlights the necessity for Peru to revise its forest regulations to meet its net-zero greenhouse gas emissions target by 2050. The research underscores the importance of prioritizing the protection of large trees in the Peruvian Amazon, which play a significant role in carbon storage.

Dr. Geomar Vallejos-Torres, the study's corresponding author and a principal investigator at the National University of San Martín, Peru, stated, "Felling trees with a diameter at breast height of at least 41 cm, depending on species, releases disproportionately large amounts of carbon into the atmosphere, making the net-zero goal difficult or even impossible to achieve."

Peru, possessing the ninth-largest forest cover globally and the second-largest within the Amazon, stores approximately 6.9 million tons of CO₂ equivalent above ground. However, official monitoring indicates that 150,602 hectares of Amazonian forest were lost in 2024 alone, highlighting ongoing pressures on these ecosystems.

Current Peruvian forest policy permits the harvesting of trees once they reach a minimum diameter at breast height, ranging from 41 to 61 cm depending on the species. This regulation results in the selective logging of the largest trees, which are vital for carbon sequestration.

The study examined five representative forests in the San Martín department of northern Peru: Ojos de Agua, Huallaga, Bajo Huallaga, Alto Mayo, and Alto Roque. Researchers measured 535 trees across 100 sampling plots, recording variables such as diameter, height, crown area, and wood density to estimate biomass and carbon storage.

Findings revealed that large trees, those with a diameter at breast height of at least 41 cm, store between 88% and 93% of a forest's carbon, depending on the species. For instance, in the species Brosimum alicastrum, 88.6% of above-ground carbon is stored in trees exceeding this diameter, while Manilkara bidentata stores 92.1% of its below-ground carbon in larger trees.

The authors concluded that existing regulations are counterproductive, as they prioritize the logging of trees that are most crucial for carbon storage. They recommend policy changes to protect large trees as a key strategy for achieving net-zero emissions by 2050.

Dr. Vallejos-Torres warned, "The current resolution could generate serious problems for forest conservation and carbon storage. Our results show that these largest trees are not expendable resources, but an integral part of the climate solution."

This study underscores the critical role of large trees in carbon sequestration and the need for policy adjustments to safeguard them, aligning with global climate objectives.