Peru’s Amazon rainforest holds a hidden climate solution: its largest trees. A recent study reveals these giants store a disproportionate amount of carbon, yet are also the primary targets of logging operations. This creates a dangerous cycle where the most effective carbon sinks are systematically removed, accelerating atmospheric carbon release.
The Carbon Storage Paradox
Nearly 60% of Peru is forested, with the Amazon representing 11% of the total rainforest. Current Peruvian forestry laws permit selective harvesting based on minimum tree diameter (41-61cm), incentivizing companies to take the largest specimens. Larger trees yield higher-value wood, reducing transportation costs and labor time. However, these are also the trees that have spent decades or centuries accumulating carbon.
Researchers, led by Geomar Vallejos-Torres, measured hundreds of trees across five Peruvian forests. Their findings confirm that carbon storage increases dramatically with trunk diameter. Trees exceeding 41cm hold between 88% and 93% of the total aboveground carbon. For example, breadnut trees store 88.7% of their carbon in trees larger than this threshold, compared to only 11.4% in smaller ones. The forests studied sequester up to 331 metric tons of carbon per hectare aboveground and 47 metric tons belowground.
Why This Matters
This isn’t merely an academic point. The study underscores a fundamental conflict: Peru’s forestry policy actively targets the most valuable carbon reservoirs. If unchecked, this practice undermines the Amazon’s role as a critical climate regulator. The larger trees are not just storing more carbon, they are also older and denser, meaning they will continue to accumulate carbon for centuries.
Debates and Challenges
Some experts question whether tree size is the sole measure of carbon retention. Ulf Büntgen of Cambridge argues carbon residence time is more important, especially in the tropics. However, Vallejos-Torres counters that smaller trees grow too slowly to compensate for the loss of old-growth giants. Martin Perez Lara of the WWF suggests well-managed selective harvesting can be climate-positive, but the study highlights that this may not be the case when targeting the largest, most carbon-rich trees.
The biggest obstacle remains economic reality. A legal reform protecting these trees would threaten the timber industry, which wields significant influence over Peruvian forestry policy. Vallejos-Torres acknowledges this political challenge, expressing skepticism about meaningful change.
Ultimately, preserving Peru’s largest Amazonian trees is not just an environmental issue, but a matter of climate security. Failure to protect these carbon stores will accelerate atmospheric warming and weaken the Amazon’s ability to act as a natural climate buffer.
