South American pampas lost 20% of grassland 1985–2022
The grassland vegetation of the South American pampas—a biome covering more than 1 million km² between Brazil, Argentina, and Uruguay—suffered a loss of 20 percent, including 9.1 million hectares of native grassland, from 1985 to 2022. Calculations were based on satellite images taken by MapBiomas Pampa, a collaborative network of experts from the three nations.
Of the mapped area, 66 percent lies in Argentina (72 million hectares), 18 percent in Brazil (19.4 million), and 16 percent in Uruguay (17.8 million).
The South American pampas occupy 6.1 percent of South America. It covers the southern half of Rio Grande do Sul state (in Brazil), all of Uruguay, and the portion of Argentina south of the Plate river. MapBiomas Pampa reported that the region’s biodiversity is characterized by native herbaceous vegetation known as grassland. “Though present,” the text continues, “forests occupy a smaller proportion. The region’s climate varies from subtropical to temperate, with a pronounced thermal seasonality of cold winters and hot summers, and no dry season. Rainfall occurs every month of the year.”
The data show that native vegetation currently covers less than half of the pampas (47.4%), most of it grassland (32%), which has traditionally been used in animal husbandry. Scientists regard it as unique, as it combines animal production and biodiversity conservation “with remarkable environmental sustainability.”
Transformation
Animal husbandry areas, however, are being shifted to agricultural production, planted pastures, and forestry, which now occupies almost half of the region (48.4%). The assessment found that agricultural and forestry areas expanded 15 percent over the period, or 8.9 million hectares.
The maps also showed that, even though forestry grew less, it advanced by 2.1 million hectares—a surge of 327 percent. Grassland areas went from 44 million hectares in 1985 to 35 million in 2022. This vegetation is the basis for animal production and the biome’s natural vocation.
In an interview with Agência Brasil, biologist Eduardo Vélez, a member of the MapBiomas Pampa team, said there has been a sharp rise in global commodity prices in the last decade, which has led to a region characterized by beef cattle to migrate to soybean production, “due to higher economic gains. The phenomenon happened across all three countries. In Brazil, it was more intense in terms of proportion. It was the country that lost the most in terms of grassland vegetation in this time span,” he reported.
Brazil
The loss of grassland in Brazil has reached 2.9 million hectares, the study reports. The reduction over the 38-year window alone is equivalent to 32 percent of the area that existed in 1985. “If we look at a map of Brazil, the pampas are nearly insignificant, which is why nobody pays attention to them, but they’re an important biome, and a part of Brazil’s biological diversity,” he noted.
According to the assessment, agricultural land use rose by 2.1 million hectares between 1985 and 2022. Forestry, on the other hand, increased its size by more than 720 thousand hectares—a surge of 1,667 percent. The total area occupied by grassland in 1985 was 9 million hectares, compared to no more than 6.2 million in 2022.
When the mapping began, in 1985, the transformation was already underway at significant levels. Back then, agriculture, forestry, and urban areas took up 40 percent of the region. But the landscape never ceased to change. The result is that the process of converting natural environments into anthropized areas—places whose original characteristics are altered by human occupation—has not stabilized in the region.
“We had hoped it would stabilize in recent years and that the area of agriculture and natural vegetation would be maintained, but it continues every year. It’s not over yet. It has environmental consequences: we’re losing biodiversity, several species are threatened and becoming endangered—especially plants—not to mention the loss of water seeping into the soil and the increase in contamination by pesticides,” he said.
“The pampas today are second only to the Atlantic forest in terms of de-characterization. It’s the second most heavily destroyed biome. In the Atlantic forest it’s stabilized—but not yet in the pampas. This worries us a lot. It’s as if Brazil weren’t looking at the pampas,” said the biologist.
Animal husbandry in the pampas is different from the one practiced in the Central-West and North of the country, where native forests are replaced with exotic vegetation before pasture areas are defined, the biologist pointed out. In the south, he went on, not using grassland vegetation also hampers the production of the so-called green meat.
“It’s a form of animal husbandry that coexists with native vegetation in an absolutely harmonious way. [Therefore,] it’s neutral in terms of carbon emissions and yields healthier meat. In addition, the animals’ way of life is much lighter for them, as they live in a natural environment. This sustainable cattle farming we have here in the pampas is starting to lose scale and a competitive economic advantage,” he said.
Argentina
The biggest loss of grassland vegetation in absolute terms was seen in Argentina, as it has the largest area of pampas of the three countries. There, the reduction amounted to 3.7 million hectares—182 times the size of Buenos Aires. In 38 years, the loss is equivalent to 16 percent of the area, which went from 23.1 million hectares in 1985 to 19.4 million in 2022. In Argentina, the cause of the reduction was the expansion of agricultural areas and pastures planted with exotic species. In the country, forestry grew by 317 thousand hectares from 1985 to 2022.
Uruguay
In Uruguay, the combined effect of the advance of agriculture and forestry has resulted in a dramatic shrinkage in grassland. Losses totaled 2.5 million hectares—47 times the size of Montevideo. In that country, the drop was 20 percent of the total area in 1985.
Agricultural land use is reported to have risen 42 percent over the 38-year period, from 3.2 million to 4.5 million hectares. In proportional terms, forestry expanded the most (748%): from 143 thousand hectares in 1985 to 1.2 million in 2022. “Forestry in Uruguay already exceeds the area observed in the pampas of Argentina (775 thousand hectares) and Brazil (762 thousand hectares),” the survey reports.
“In Argentina, the conversion to agriculture started before 85. It lost more than us and Uruguay in this period, but in proportion to what it had in 85, Brazil was the champion, unfortunately, as our environmental legislation is much stronger than theirs,” the biologist noted.
A collective effort
The collaborative network includes experts from Argentina (the National Institute of Agricultural Technology, the University of Buenos Aires, and the NGO Wildlife Foundation Argentina), Brazil (the Federal University of Rio Grande do Sul and GeoKarten), and Uruguay (the Agronomy and Science Schools of the University of the Republic, the National Institute of Agricultural Research, and the Ministry of the Environment).
