In the last 37 years, the biome has lost the equivalent of 70 times the area of the municipality of Porto Alegre

Access the Pampa highlights from MapBiomas Brazil Collection 7

Currently, the Pampa has more anthropized areas, meaning modified by human action, than native vegetation. In 1985, native vegetation areas occupied 61.3% of the Pampa; by 2021, this participation dropped to 43.2% - almost the same as agricultural areas, which already occupy 41.6% of the biome. There was a loss of 29.5% of native vegetation only between 1985 and 2021, which was accentuated in the last two decades. The data comes from the most recent survey by MapBiomas on land use and land cover in the biome covering a period of 37 years.

Made up of different types of grassland, the biome, which has seen a decrease of 3.4 million hectares - the equivalent of 70 times the area of the municipality of Porto Alegre, has seen the growing advance of agriculture result in the loss of grassland formations, the native vegetation typical of the biome and traditionally used for livestock farming. In 1985, grassland formations occupied 48.6% of the territory. In 2021, it was only 30.9%, a loss of 36%.

"The exaggerated advance of agriculture, especially soy, over areas of grassland vegetation should serve as a warning about the future of the biome. We're putting aside sustainable livestock farming, which is the natural vocation of the biome - and which allows us to produce and conserve nature at the same time - and betting everything on a few commodities, such as soy and forestry," explains Heinrich Hasenack, a researcher at UFRGS. "A poorly diversified economy increases the risk of recurring crop losses, as we've seen in recent years, especially in a climate change scenario," he explains.

Forestry currently occupies 3.8% of the biome and was the cover with the highest proportion of growth in the period from 1985 to 2021, an increase of 1,641%. Although it is found throughout the Pampa, forestry is very concentrated in the central-eastern region of the biome. The five municipalities that have seen the most growth in forestry in the last 37 years are Encruzilhada do Sul, Piratini, Canguçu, Dom Feliciano and Butiá.

The mapping also reveals the number and location of marshes, rocky outcrops, dunes and coastal lagoons, natural ecosystems of great ecological importance that are part of the Pampa's natural heritage.

"The changes in land use in the Pampa have been very expressive in only one direction, which is very worrying since they don't point to a path of environmental sustainability. We should implement public policies to promote livestock farming, diversify production in rural areas, encourage rural tourism and care for the Pampa's natural heritage, such as the creation of new conservation units," warns Hasenack.

The results of the biome mapping also show that 1 in every 4 hectares of native vegetation in the Pampa is secondary vegetation - that which has already been cleared at least once and ended up regenerating. Between 1985 and 2021, 2.2 million hectares of native vegetation became secondary vegetation, which is equivalent to more than 45 times the size of the municipality of Porto Alegre. In other words, of the 43.2% of the biome that is still covered by native vegetation, more than 25% is already secondary.