Scientists have long studied the Amazon Basin\u2019s impact on rainfall<\/a> in southern Brazil, but much less attention has been given to its importance for Andean countries, even though flying rivers provide more than 70% of precipitation<\/a> in parts of southern Peru and northern Bolivia.<\/p>\n A recent white paper<\/a> from the NGO Amazon Conservation highlights flying rivers\u2019 transnational effects by showing how deforestation in Brazil risks reducing rainfall in Peru and Bolivia.<\/p>\n It builds on earlier research<\/a> by Amazon Conservation\u2019s Monitoring of the Andes Amazon Program (MAAP), which mapped the flying rivers\u2019 pathways through the wet, dry and transition seasons and identified the most sensitive areas in the Andean Amazon.<\/p>\n The new report identifies the forests at risk of being cleared along these pathways and offers recommendations for how to protect the invisible moisture flows.<\/p>\n \u201cIt is more critical that forest is retained along the pathway than in other places, because the [flying] rivers do take a specific course, and if forest cover was to be removed along that path, then it would affect the ability of these rivers to continue flowing by constantly recycling humidity,\u201d said co-author of the report Blaise Bodin, Amazon Conservation\u2019s director of strategy and policy.<\/p>\n At least 75% of the moisture from rain<\/a> in the Amazon is recycled into the atmosphere by the forest, a process that is repeated five or six times as the water vapor travels toward the Andes.<\/p>\n \u201cThere has already been a reduction in flying rivers because, in the south of the Amazon, there is already one million square kilometers of deforested [land turned into] pasture, crops, soy,\u201d said Nobre, a professor of climate and sustainability at the Universidade de S\u00e3o Paulo who wrote the report\u2019s foreword.<\/p>\n \u201cAnd pasture and soy recycle much less water. In the dry season, these plantations recycle a third or a quarter [of what forests do],\u201d Nobre told Mongabay during a press conference in Rio de Janeiro on June 11.<\/p>\n The resulting reduction in rainfall risks inducing a \u201ctipping point\u201d<\/a> in parts of the Amazon, where the forest would turn into a savanna ecosystem. The southwestern Amazon in Peru and Bolivia is most vulnerable to experiencing such a tipping point, the MAAP research found.<\/p>\n Identifying deforestation risks<\/p>\n \u201cThe wet season [pathway] is pretty well conserved, it flows over a lot of protected areas and Indigenous territories, and just generally intact forest,\u201d co-author of the report Matt Finer, director and senior research specialist at MAAP, told Mongabay in a video interview.<\/p>\n The transition and dry season pathways, however, not only cross more deforested areas in Brazil, but also pass over territories that are at risk of being cleared \u2013 notably undesignated public forests (UPFs), areas without formal protection that belong to the state or federal governments.<\/p>\n According to the Public Forests Observatory\u2019s latest bulletin<\/a>, UPFs are the second most deforested type of land in Brazil (after large and medium private properties), vulnerable to illegal land grabbing and accounting for 20.6% of Amazon deforestation between January 2025 and April 2026. They are also vulnerable to climate extremes, seeing an increase in fires during the drought of 2024.<\/p>\n Road development also threatens the flying rivers\u2019 pathway during the dry season. One example is the controversial repaving of the BR-319 highway,<\/a> which connects the cities of Manaus and Porto Velho. There are also several road projects in the state of Acre, which borders Peru and Bolivia, including the repaving of a highway linking the state capital Rio Branco to Cruzeiro do Sul.<\/p>\n A new road has a multiplying effect on deforestation as it often leads to the clearing of forests for side roads, a phenomenon known as the \u201cfishbone effect<\/a>.<\/a>\u201d<\/a> Concern with the impact of the BR-319 has led it to be dubbed the \u201ctipping point road<\/a>.<\/a>\u201d<\/a><\/p>\n Forest cover in Acre is particularly important, because the three seasonal pathways of flying rivers converge over the west of the state. Research has also shown that the vegetation in the central-western Amazon, furthest away from the Atlantic Ocean and closest to the areas sensitive to shifts in the flying rivers, plays a more important role in recycling moisture and providing rainfall to the tropical Andes.<\/p>\n \u201cAcre is the last stretch before you get to these critical areas, so if you interrupt forest cover there, it\u2019s very likely it would lead to a drastic reduction in precipitation just downstream of the flying rivers,\u201d Bodin told Mongabay in a video interview.<\/p>\n Disruption from climate change<\/p>\n The onset of a strong El Ni\u00f1o<\/a> could also lead to a particularly fierce dry season this year. When conditions are dry, the forest has less moisture to pump into the atmosphere and less water evaporates, Bodin explained.<\/p>\n One recent study<\/a> found that the southwestern Amazon\u2019s dry season is already lasting longer, with more intense water deficit and climate unpredictability. Another<\/a> study<\/a> showed<\/a> that drought during the 2023-2024 El Ni\u00f1o led to increased fires and forest degradation in the Brazilian Amazon.<\/p>\n Both deforestation and climate change impact flying rivers in \u201ca sort of reinforcing feedback loop,\u201d Bodin said.<\/p>\n The 2023-2024 drought in the Amazon began with a severe shortage of rainfall<\/a> in the Peruvian and Bolivian Altiplano, but it is not possible to establish exactly how much deforestation contributed to this, the report noted.<\/p>\n \u201cThe models are not yet accurate enough,\u201d Bodin said, but they are being developed. A newly published paper<\/a> calculated that deforestation between 1982 and 2018 in the Amazon reduced seasonal precipitation by 6% to 30% across seven soybean states in central and southern Brazil.<\/p>\n And it is possible to observe how changes to the climate are already affecting biodiversity and communities in the areas most dependent on the flying rivers, the Amazon Conservation report said.<\/p>\n In recent years, more frequent droughts and unpredictable rainfall have severely affected activities that support rural livelihoods in southern Peru and northern Bolivia, like potato production<\/a> and Brazil nut collection<\/a>.<\/p>\n \u201cWe used to base ourselves on the seasons, but now everything has changed,\u201d said Magaly Tipuni, an Indigenous leader from the Pil\u00f3n Lajas Biosphere Reserve and Communal Land in Bolivia\u2019s Beni department. Pil\u00f3n Lajas is home to 23 Indigenous communities who cultivate rice, yucca, banana and corn for subsistence. They hadn\u2019t experienced fires prior to 2023, Tipuni told Mongabay over the phone.<\/p>\n \u201cFirst came the drought, and from the drought came the fire. The fire burnt many animals and plants, even parts of our communal crops. And the following year, the floods came,\u201d she said.<\/p>\n Evapotranspiration as a factor for conservation<\/p>\n Putting Brazil\u2019s roughly 50 million hectares (around 123 million acres) of UPFs under formal protection could be an important step to protecting the flying rivers, but the report\u2019s authors defend a more targeted approach.<\/p>\n They recommend that the criteria for designating new protected areas and undertaking infrastructure projects like roads should take into account a forest\u2019s contribution to atmospheric moisture.<\/p>\n \u201cLet\u2019s start incorporating flying rivers into the list of things to consider when you are doing environmental assessments and project planning,\u201d Finer said.<\/p>\n When the first conservation units were created in Brazil, they considered factors like species and ecosystems, said Erika Guimar\u00e3es, leader for protected areas at WWF-Brazil. \u201cNow we have an understanding that we also create conservation units to promote ecosystem services,\u201d she said.<\/p>\n \u201cThe production of rain or moisture in the Amazon is a role that is now crystal-clear, [but] I don\u2019t think it\u2019s something which has been consciously incorporated,\u201d she added. \u201cIt would be interesting to develop and perfect models to take this criterion into account.\u201d<\/p>\n These same models could be used by companies to calculate a project\u2019s impact on deforestation and therefore, moisture, Bodin said, while acknowledging that this requirement would need to be included in the Brazilian government\u2019s environmental licensing rules. At the same time, recent law changes<\/a> in Brazil have led to a simplification of the environmental licensing process for projects like the BR-319<\/a>.<\/p>\n The countries that depend on the flying rivers also have a role to play, Finer said, citing the example of Manu National Park in Peru. \u201cFor an official in Peru, half the [conservation] strategy is avoiding deforestation in Manu, but the other half is diplomacy, perhaps, and making sure that Brazil doesn\u2019t trigger excess deforestation that cuts off the moisture flow,\u201d he said.<\/p>\n Banner image: Soy plantations abut the Amazon rainforest in southern Brazil. Image by Rhett A. Butler\/Mongabay.<\/p>\n Citations:<\/p>\n Finer M, Ari\u00f1ez A, Sierra JP, Espinoza JC,, Weng W, Vriesendorp C, Bodin B, Beavers J (2025) The Amazon Tipping Point \u2013 Importance of Flying Rivers Connecting the Amazon. MAAP: 232<\/a>.<\/p>\n Lovejoy, T. E., & Nobre, C. (2019). Amazon tipping point: Last chance for action. Science Advances, 5(12). doi:10.1126\/sciadv.aba2949<\/a><\/p>\n Dutra, D. J., Ferreira, I. J. M., Rodrigues, \u00c9. T., Braga, D., Izidoro, B., Mataveli, G., Arag\u00e3o, L. E. O. C. de, & Anderson, L. O. (2026). Intensification of drought-associated wildfires challenges actions for Amazonia\u2019s sustainable development. Perspectives in Ecology and Conservation, 24(2). doi:10.1016\/j.pecon.2026.02.013<\/a><\/p>\n Dutra, D. J. , C. Jones , R. A. Betts , et al. (2026). Dry-Season Water Deficits in the Southwestern Amazon Under High Emissions. International Journal of Climatology, 46(6). doi:10.1002\/joc.70331<\/a><\/p>\n Li, H., Lesk, C., Zhu, L., Crowther, T., Chen, M., Ray, D., & Mueller, N. (2026). Amazon deforestation reduces precipitation and soybean yields across Southern Brazil. Proceedings of the National Academy of Sciences, 123. doi:10.1073\/pnas.2525378123<\/a><\/p>\n FEEDBACK: Use this form<\/a> to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.<\/p>\n Cite this articleConstance Malleret (2026). Targeted conservation in Brazil could help protect the Amazon\u2019s flying rivers. Mongabay Conservation news. DOI: https:\/\/doi.org\/10.66709\/news-322348<\/a> <\/p>\n ![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/20211022_151003-1200x800.jpg\")
Aerial view in Manaus, in the Brazilian state of Amazonas. Photo courtesy of Hans ter Steege.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/Figure-2-FR_ENG.png\")
Flying river pathways for the three seasons, overlaid on land designations and key road development projects. Image courtesy of Amazon Conservation Association.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/Brazil-Climate-Amazon-Drought.jpeg\")
The Taruma Acu River is visible amid a severe drought in Manaus, state of Amazonas, Brazil, Wednesday, Sept. 25, 2024. (AP Photo\/Edmar Barros)<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/Figure-4.png\")
Seasonal pathway to the sensitive areas for the dry season, showing overlap with the watershed of the Madeira River and its tributaries. Image courtesy of Amazon Conservation Association.<\/p>\n![\"BR-319](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/319_4_div_min_transp-1200x800.jpeg\")
BR-319 highway cuts through some of the Amazon\u2019s most conserved areas, home to 69 Indigenous territories and 41 conservation units.\u00a0 Amazon Conservation\u2019s report found that road development threatens the pathway of flying rivers during the dry season. Image courtesy of the Ministry of Transportation.<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/6ddc11ab3173ab5e21a8b9ce7c4f11c7fc908bb2b47d47eaf0789863708a3588.png\")
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