Loss of vegetation cover in the Upper Paraguay Basin Highlands worsens drought in the biome
November 12, 2025
The Pantanal, the world’s largest tropical wetland, is experiencing its driest period in four decades. A survey conducted by MapBiomas—based on Collection 10 of land use and cover maps in Brazil covering 1985 to 2024—reveals that the annual area remaining flooded in the biome has decreased by 75%. It dropped from 1.6 million hectares in the first decade (1985-1994) to 460,000 hectares in the last decade (2014-2024). The year 2024 was the driest in the entire historical series, with the flooded area falling 73% below average. The last major flood, recorded in 2018, was 22% drier than the first major flood of the series in 1988. The biome has faced smaller flood pulses and more severe droughts with each passing decade.
Changes in the Pantanal Plains (Planície) are directly correlated with transformations in the Upper Paraguay Basin Plateau (Planalto), where the rivers that feed the Pantanal originate. The BAP covers areas of the states of Mato Grosso (48% of the BAP; 17.4 million hectares) and Mato Grosso do Sul (52% of the BAP; 18.6 million hectares). While the Pantanal biome corresponds to the Plains, the Plateau is divided between the Cerrado (83%) and the Amazon (17%).
Vegetation cover alterations were most intense on the Plateau, directly impacting the water flow between the Plateau and the Plains. Natural areas on the Plateau dropped from 72% to 46% in Mato Grosso and from 59% to 36% in Mato Grosso do Sul—a total loss of 5.2 million hectares (37%) of native vegetation between 1985 and 2024. During this same period on the Plateau, agriculture increased 3.8 times (1.4 million hectares), with soy representing 80% of agricultural areas. Pastureland expanded by 4.4 million hectares over native vegetation, intensifying human-modified (anthropic) areas in the region
“Climate variations and precipitation in the BAP determine the annual flood pulse in the Pantanal. The loss of Forests and Savannas weakens soil protection at the biome’s headwaters, interfering with the flow of water reaching the Plains. In 1985, 33% of the Plateau, or seven million hectares, were already under human use. By 2024, practically 60% of the Plateau has been anthropized,”explains Eduardo Reis Rosa, coordinator of the MapBiomas Pantanal team.
The condition of pastures on the Plateau is also an aggravating factor. In 2024, 63% of pastures showed low or medium vegetative vigor. Of the 8.6 million hectares of pasture on the Plateau, the portion within the Amazon (2,068,850 hectares) shows 52% low vigor and 40% medium vigor, while the Cerrado portion (6,620,165 hectares) has 14% low vigor and 41% medium vigor.
In the Pantanal Plains, the changes were also significant. Natural areas dropped from 96% to 84% between 1985 and 2024, with a total loss of 1.7 million hectares of native vegetation. This includes 0.7 million hectares in the Mato Grosso portion (where natural areas fell from 96% to 84%) and 1.1 million hectares in the Mato Grosso do Sul portion (where natural areas fell from 96% to 85%).
The conversion of native vegetation to pasture accounted for this entire 1.7 million-hectare loss over 40 years. Pasture area grew from 563,000 hectares in 1985 to 2.2 million hectares in 2024. Data on pasture condition shows that in 2024, 85% of pastures on the Plains had low or medium vegetative vigor. Mining was the human activity that grew the most proportionally in the last decade in the Pantanal, with a 60% increase.
Across the entire Upper Paraguay Basin, agricultural and livestock areas increased from 21% in 1985 to 40% in 2024, totaling 7.5 million hectares converted from native vegetation in four decades. Of this total, 84% (12 million hectares) of agricultural activity is on the Plateau and 16% (2.3 million hectares) on the Plains.
Decadal Analysis of Plateau and Plains Dynamics:
1985–1994: The largest conversion of savanna formations to pasture occurred. Pasture area doubled (592,000 hectares). The Plateau lost 12% of its native vegetation (2.6 million hectares).
1995–2004: Deforestation advanced into the interior of the Pantanal biome, with a loss of 527,000 hectares (3%) of its native vegetation. On the Plateau, the loss was 9%.
2005–2014: For the first time, a reduction in flood frequency and woody encroachment (adensamento lenhoso) were observed, with 350,000 hectares of savanna formations expanding over grasslands and pastures.
2015–2024: The driest decade, with a reduction of 1.2 million hectares (compared to the first decade) in the annual area that remains flooded. In this last decade, the Pantanal Plains lost more native vegetation (450,000 hectares) than the Plateau, which maintains, in 2024, 42% of natural areas, while the Pantanal has 84% of the biome with natural areas.