Protecting Existing Amazon Forests Yields Greater Climate and Biodiversity Gains Than Restoration, Study Finds

Governments, carbon market regulators, and climate financiers allocating billions of dollars to tropical conservation face a persistent operational choice between planting new trees and guarding the ones that are still standing. A comprehensive decade-long analysis of the Brazilian Amazon, published this week in the journal Science, provides a definitive empirical ledger for that decision.

The research demonstrates that keeping existing forests free from logging and fire delivers vastly superior biodiversity and carbon returns than restoring cleared land, and does so at a fraction of the cost. The findings challenge the heavy emphasis that international climate frameworks often place on high-visibility tree-planting campaigns, suggesting that capital deployed to protect mature ecosystems yields a significantly higher ecological return on investment.[1][2]

The research, led by scientists at Lancaster University and the Brazilian Agricultural Research Corporation (Embrapa), modeled land-use changes across more than three million hectares in the Santarém and Paragominas regions of Pará between 2010 and 2020.

By combining high-resolution satellite imagery with granular data from 381 survey transects and 499 rural properties, the team quantified the ecological and financial outcomes of three distinct interventions. They evaluated the impacts of avoiding outright deforestation, preventing forest disturbances such as understory wildfires and selective logging, and active restoration efforts designed to bring properties up to the minimum forest cover required by Brazilian law.[1][3]

The resulting data upends the conventional prioritization of ecosystem recovery over the protection of degraded but standing forests. According to the models, preventing forest disturbances—specifically keeping fires and logging operations out of standing old-growth forests—mitigated 68.5 percent of projected biodiversity losses under a business-as-usual scenario. It also prevented 46.8 percent of carbon losses.

Avoiding outright deforestation delivered the strongest carbon outcome, mitigating 60.8 percent of projected losses, alongside a 28.0 percent reduction in biodiversity loss. By stark contrast, restoration efforts implemented as a standalone strategy compensated for just 6.5 percent of biodiversity losses and 14.7 percent of carbon losses.[1]

When the researchers evaluated the strategies for cost-effectiveness, the disparity between protection and planting widened even further. The team priced each conservation strategy pixel by pixel, factoring in reported farm incomes, the market value of timber, and the operational costs of cutting and maintaining firebreaks.

Avoiding disturbances proved to be the most cost-effective method for preserving biodiversity, yielding 0.372 average weighted occurrence probabilities per 10,000 Brazilian reais spent. Preventing deforestation delivered the most efficient carbon retention, securing 52.0 megagrams of carbon for the same price. Restoration consistently ranked last, remaining the most expensive and least effective option even when the model artificially reduced its implementation costs by 95 percent.[1]

"Restoration is essential where forests have been lost across large areas. But our study shows that investing in new forests makes little sense if, at the same time, we fail to protect existing forests," said Dr. Joice Ferreira, a senior researcher at Embrapa and a co-author of the study.

"Otherwise, we are pouring money into a leaky pot—restoring forests in one place while others are being degraded and lost." Her assessment underscores the biological reality that old-growth tropical forests possess complex, interconnected networks that take centuries to develop and cannot be quickly replicated by planting saplings on degraded agricultural land.[1][2][3]

The findings highlight a critical operational gap in international climate finance frameworks. While global initiatives like the United Nations Decade on Ecosystem Restoration heavily promote replanting, and programs such as REDD+ focus primarily on halting clear-cut deforestation, the less visible degradation caused by selective logging and understory fires receives comparatively little funding and regulatory attention.

Yet, across the studied decade in Pará, fire and logging damaged significantly more total forest area than was entirely cleared. The researchers argue that avoiding forest disturbance must become a central pillar of national policies and international carbon markets if the world is to meet its climate pledges.[1]

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The optimal approach, the study confirms, is a layered defense that integrates all three strategies based on precise local conditions. When avoidance strategies were combined with restoration, the landscape saw net ecological gains, increasing biodiversity and carbon by 12 percent and 18 percent, respectively, above the 2010 baseline.

The researchers noted that restoration only outperformed protection on properties that had already lost more than 57 percent of their original forest cover. Below roughly 43 percent forest cover, tree planting beat avoided deforestation for biodiversity, dictating that conservation capital must be deployed dynamically rather than through blanket regional mandates.[1][3]

As the 2026 El Niño intensifies heat and drought across the Amazon basin, the threat of widespread wildfires is accelerating, placing immense pressure on the region's remaining intact ecosystems. For policymakers, environmental ministries, and carbon market regulators preparing for the next round of climate finance disbursements, the mandate from the data is clear. Securing the perimeter of the existing Amazon and shielding it from further degradation is the absolute prerequisite for any successful ecological recovery, ensuring that future investments in restoration are built on a stable biological foundation.[2][3]