Efforts to stop deforestation and restore cleared land are central to many conservation programs. But a new study published in Science suggests that preventing disturbances within existing forests, including selective logging and wildfires, can sometimes deliver the greatest benefits for the money spent.

An international research team from the UK, Brazil, Sweden and Australia, led by scientists at Lancaster University, carried out what the researchers describe as the first systematic comparison of its kind. The team evaluated different strategies for protecting existing forests and restoring forests on agricultural land.

Comparing Conservation Strategies Across the Amazon

The study examined more than three million hectares in Santarém and Paragominas, two regions in the Brazilian state of Pará, over the period from 2010 to 2020.

Researchers combined high-resolution satellite imagery with extensive field observations. Their dataset included 381 survey transects across 38 catchments and 499 rural properties, along with models charting the distributions of 160 bird species and 426 tree species.

The team then used observed changes in land use to construct counterfactual scenarios. These models allowed the researchers to estimate what might have happened to biodiversity and forest carbon stocks under different conservation approaches compared with what actually occurred.

They also calculated the costs associated with each strategy, making it possible to compare how much environmental benefit each intervention could provide for the resources invested.

"These findings highlight the need to put in place policies and resources to prevent and tackle the wildfires that disturb and degrade tropical forests," said Professor Jos Barlow, of Lancaster University and senior author of the study.

"This is all the more urgent in this El Niño year. These events, combined with climate change, result in longer, hotter and more intense dry seasons across the Amazon's 'arc of deforestation', greatly increasing the extent and severity of forest fires."

Protecting Standing Forests Produced Major Gains

Preventing damage to forests emerged as especially important. Measures that reduced disturbances generated the largest benefits for forest biodiversity and were nearly as important as preventing outright deforestation when it came to safeguarding carbon stocks.

"While no one strategy is a silver bullet, our results provide clear evidence that we should begin by prioritizing the forests we have left," said Dr. Leonardo Miranda, of Lancaster University and lead author of the study. "And protection must go beyond avoiding deforestation. Avoiding forest disturbances from wildfires or logging delivered the greatest benefits for forest biodiversity."

Forest restoration also provided meaningful benefits, particularly on properties where much of the original forest had already disappeared.

Across the entire study area, however, restoring forest on agricultural land was less effective when used by itself. It was also the most expensive of the strategies evaluated. The findings suggest that conservation funding should be tailored to the conditions of individual landscapes rather than relying on a single approach everywhere.

No Single Strategy Was Enough

None of the interventions on its own was able to reverse the overall losses of biodiversity and carbon across the full study area.

"Net gains in biodiversity and carbon storage were only achieved when both avoidance interventions were implemented. However, combining all three interventions delivered even greater gains," said Dr. Miranda. "Combined interventions will be even more important as climate change progresses, especially as forest restoration can be particularly vulnerable to wildfires."

That finding is especially relevant as governments and international organizations place increasing emphasis on forest restoration. Both global environmental commitments and Brazilian federal and state policies include major efforts to bring forests back to areas where they have been lost.

Restoration Works Best Alongside Protection

The researchers emphasize that restoration remains necessary, especially in landscapes where widespread clearing has already occurred. But restoring forests while existing forests continue to be damaged can undermine the overall benefits.

"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 the co-author Dr. Joice Ferreira, senior researcher at Embrapa and the principal investigator of the 'Capoeira' research program on restoration. "Otherwise, we are pouring money into a leaky pot - restoring forests in one place while others are being degraded and lost. What we urgently need to do is integrate these policy agendas, ensuring that forest restoration goes hand in hand with protection of the forests we still have."

Although the research focused on two regions of the Amazon, the scientists say its conclusions may also apply to tropical deforestation frontiers elsewhere in the world. The findings could also have implications for conservation policy beyond tropical regions.

Soy, Beef and Forest Degradation

The researchers also argue that responsibility for forest conservation extends beyond governments and conservation organizations. Industries and markets tied to commodities produced in areas experiencing forest loss and degradation may also need to address their role.

"There is a need for the companies and markets that benefit from nationally and globally traded commodities like soy and beef to take responsibility not only for deforestation, but also the degradation of remaining forests that is inextricably linked to these production systems," said Dr. Toby Gardner, co-author and Senior Research Fellow at Stockholm Environment Institute and co-founder of the supply chain sustainability initiative Trase.

The findings are detailed in the paper "Protecting tropical forests is more cost-effective for biodiversity and climate than restoration" published in Science on September 17, 2026.

The research was convened by the Sustainable Amazon Network (Rede Amazonia Sustentavel) and funded by sources including UK's Global Centre on Biodiversity for Climate and Brazil's National Council for Scientific and Technological Development (CNPq).