More than 6 per cent of the Amazon’s floodplain forests and other wetland areas have been converted for human use over the past four decades with nearly one third of the total destruction occurring between 2015 and 2024 according to a new study.
The converted area is roughly equivalent to the size of Belgium, highlighting the growing pressure on one of the world’s most ecologically important tropical regions.
Amazonian wetlands are seasonally flooded by rivers that overflow their banks for months each year. These ecosystems cover around 30 per cent of the Brazilian Amazon and support diverse wildlife as well as riverine communities that depend on fishing, agriculture and other forest resources. Many families live in houses built on stilts to adapt to changing water levels.
The study examined wetland conversion across 13 types of land designations, revealing substantial differences in how land ownership, governance and management rules influence deforestation.
Undesignated public lands face the greatest losses
Public land that has not been assigned a specific government use recorded the highest share of wetland conversion. A median of nearly 14 per cent of wetlands in these areas had been cleared.
Researchers linked much of this pressure to land grabbing, locally known as grilagem. In some cases, people clear or burn public land to demonstrate that they are using it, hoping to obtain formal land titles later.
A 2026 study by a Brazilian research institute found that federal and state land laws can create incentives for these practices. Where clearing is treated as evidence of productive land use, deforestation can become a means of strengthening claims to public land.
The findings suggest that unclear land tenure and policies that reward clearing can encourage the destruction of valuable wetland ecosystems.
Protected and Indigenous lands record lower conversion
Wetland conversion was substantially lower in areas with stronger protections or established conservation arrangements.
Military controlled areas recorded conversion rates below 0.01 per cent the lowest among the land categories examined.
Formally recognised Indigenous territories had a wetland conversion rate of around 0.2 per cent, while Indigenous lands awaiting formal demarcation recorded approximately 0.3 per cent. Other strictly protected areas also reported conversion rates below 0.3 per cent.
These results highlight the importance of Indigenous stewardship and land protection in maintaining forest and wetland ecosystems. They also suggest that formal recognition of Indigenous territories can help secure areas that communities have long inhabited and protected.
Agrarian settlements experience rapid wetland loss
Government agrarian reform settlements, where plots of land are allocated to farming families, recorded some of the fastest increases in wetland conversion.
Within five years of a settlement being established, approximately 1.4 per cent of its wetlands had been converted for human use, compared with 0.9 per cent before settlement.
After 15 years, the proportion of converted wetlands had reached 24 per cent up from 8.5 per cent before the settlements were established.
The study suggests that settlement policies can contribute to this trend when residents are required to demonstrate productive land use but receive limited environmental monitoring or support for livelihoods that depend on keeping forests intact.
By contrast, sustainable agrarian reform settlements where families collectively hold land and harvest forest products, experienced more gradual changes. Wetland conversion in these areas increased from around 2.4 per cent to approximately 3.5 per cent over the period examined.
The difference indicates that the way settlements are designed and managed can influence their environmental outcomes.
Rules and governance shape conservation outcomes
The research points to land governance as a key factor in determining whether Amazonian wetlands remain intact or are converted for other uses.
The contrast between undesignated public land, Indigenous territories protected areas and different types of agrarian settlements suggests that ownership alone is not enough to guarantee conservation. Clear rules, effective monitoring and support for sustainable livelihoods also matter.
Amazon wetlands play an important role in supporting biodiversity and maintaining ecological processes, while providing food and resources for local communities. Their continued conversion could undermine these benefits and place additional pressure on people whose livelihoods depend on healthy rivers and forests.
The findings underline the need for stronger protection of public lands, effective recognition of Indigenous territories and better designed settlement policies that do not encourage forest clearing as proof of productive use.
As wetland losses continue to rise, improving land governance and supporting livelihoods compatible with conservation will be essential to safeguarding the Amazon’s seasonally flooded ecosystems.