Guarding standing forest outperformed restoration across 3 million hectares of Para

The design turns on what each strategy is compared against. The team took the land-use changes that actually happened in Santarem and Paragominas between 2010 and 2020 and re-ran the decade with each intervention switched on, scoring the difference in biodiversity and carbon stocks against the outcome that really occurred ^[5]. A modelled counterfactual is the nearest available substitute for a control group at this scale. It also carries the model's assumptions. If the projection of how land use would otherwise have moved is wrong, the ranking of the three strategies moves with it.

The field layer is thinner than the study area implies. There are 381 survey transects across more than 3 million hectares, roughly one per 7,900 hectares ^[19], and those transects, spread over 38 catchments and 499 rural properties, anchor the satellite imagery and the distribution models for 160 bird species and 426 tree species ^[4]. Biodiversity here means those two groups, 586 species in total ^[21].

Against that decade of real change, avoiding forest disturbance produced the largest gains for forest biodiversity and came almost as close as halting deforestation to protecting carbon stocks ^[7]. "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 Leonardo Miranda of Lancaster University, the study's lead author ^[12].

Restoration mattered most on properties where most of the original forest was already gone ^[8]. Across the study area as a whole it was the least effective option when implemented on its own, and the most expensive ^[9]. The costs are the team's estimates of what each intervention takes to implement, compared in a common framework ^[6]; the phys.org account of the paper does not include the per-hectare figures.

"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," Miranda said ^[11]. No single intervention reversed biodiversity and carbon losses across the entire study area ^[10].

Fire is the part no landowner can buy alone. "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 Jos Barlow of Lancaster University, the senior author ^[13]. Barlow said El Nino events combined with climate change produce longer, hotter and more intense dry seasons across the Amazon's arc of deforestation, greatly increasing the extent and severity of forest fires ^[14]. The 2026 El Nino is intensifying across the region now ^[15].

Joice Ferreira of Embrapa, a co-author and principal investigator of the Capoeira restoration research program, gave the policy version. "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," she said ^[16]. The paper arrives as restoration takes a growing role in global commitments and in Brazilian federal and state policy ^[18].