Grasslands of South America

Grasslands of South America
Name	South American Grasslands
Biome	Temperate and Tropical Grasslands, Savannas, and Shrublands
Countries	Argentina, Brazil, Uruguay, Paraguay, Bolivia, Venezuela, Colombia, Chile, Peru

Grasslands of South America South America's grasslands form a mosaic of temperate and tropical plateaus, plains, and pampas that span from the Patagonia steppe to the Llanos and the Cerrado. These regions have been shaped by tectonics associated with the Andes uplift, climatic regimes tied to the South Atlantic and Pacific Ocean circulation, and millennia of interactions with Indigenous cultures such as the Guarani and the Mapuche. Major political entities intersecting these landscapes include the Federative Republic of Brazil, the Argentine Republic, and the Oriental Republic of Uruguay.

Geography and Extent

South American grasslands encompass the Pampas of Argentina, the Uruguayan grasslands, the Pantanal-adjacent savannas, the Cerrado of central Brazil, the Llanos of Venezuela and Colombia, and the Patagonian steppe in southern Chile and Argentina. The biogeographic boundaries relate to physiographic provinces such as the Paraná Basin, the Gran Chaco, and the Guiana Shield fringe, and to river systems like the Paraná River, the Paraguay River, and the Orinoco River. Elevational gradients run from the lowland floodplains near Amazonas to the high interior plateaus of the Altiplano periphery.

Climate and Soils

Climatic controls derive from interactions among the South Atlantic Convergence Zone, the El Niño–Southern Oscillation (ENSO), the South American Monsoon System, and polar influences via the Falkland Current. These produce temperate humid conditions in the Pampas, pronounced wet and dry seasons in the Llanos, and pronounced seasonality in the Cerrado. Soils include fertile mollisols in the Argentine Pampas, dystrophic oxisols and ultisols in parts of the Cerrado and Brazilian Highlands, and aridisols across Patagonian steppe zones; major soil-forming processes reflect provenance from Andean erosion and sedimentation in the Paraná Basin.

Vegetation Types and Plant Communities

Vegetation ranges from tallgrass prairies dominated by genera such as Paspalum in the Pampas to cerrado scrub and gallery forests in river corridors bordering the Cerrado. Distinct plant communities include humid tallgrass steppes, xerophytic shrublands on the Patagonian plateau, and seasonally flooded grasslands in the Llanos and Pantanal. Woody encroachment with species like Prosopis occurs in parts of the Gran Chaco, while riparian patches host taxa associated with the Amazon Rainforest and the Atlantic Forest. Fire-adapted physiognomies and C4-dominated grass assemblages reflect evolutionary history shared with regions across the Neotropics.

Fauna and Biodiversity

Faunal assemblages feature iconic mammals such as the Guanaco and Vicugna in Patagonian sectors, the Maned wolf and Giant anteater in the Cerrado, and the Capybara and Marsh deer in the Llanos and Pantanal. Grassland birds include the Greater rhea and the Screaming cowbird, while reptiles and amphibians show regional endemism tied to plateau refugia and riverine habitats, with taxa recorded by institutions like the Museo Argentino de Ciencias Naturales and the Instituto Nacional de Pesquisas da Amazônia. Invertebrate assemblages, pollinators documented by the Royal Botanic Gardens, Kew-affiliated studies, and microbial soil communities contribute to high functional diversity and to ecosystem services valued in Mercosur member states.

Human Use and Land Management

Longstanding human use includes pastoralism practiced by gaucho cultures of Argentina and Uruguay, Indigenous agroecological systems maintained by the Guarani and other groups, and modern agribusiness centered on soybean and wheat production across the Pampas and Cerrado. Land management regimes involve ranching enterprises, agroforestry trials supported by the Embrapa research network, conservation-oriented reserves like those managed by the World Wildlife Fund and national parks under ministries in the Federative Republic of Brazil and the Argentine Republic, and rural development programs tied to the Inter-American Development Bank. Infrastructure expansion along corridors such as the BR-163 and the Pan-American Highway has reconfigured land-use mosaics.

Threats and Conservation Efforts

Major threats include conversion to cropland for soybean and maize export, degradation from overgrazing, invasive species dynamics exemplified by Ulex europaeus introductions in southern sectors, hydrological alteration from dams on the Paraná River and Orinoco tributaries, and fire regime changes influenced by policies in capitals like Brasília and Buenos Aires. Conservation responses encompass protected area networks spanning federal and provincial jurisdictions, restoration initiatives by NGOs such as Conservation International and academic partnerships with universities like the Universidade de São Paulo and the University of Buenos Aires, and transboundary conservation dialogues within forums such as Mercosur and the Amazon Cooperation Treaty Organization where relevant. International instruments invoked in planning include initiatives tied to the Convention on Biological Diversity and financing mechanisms from institutions like the World Bank.

Category:Biomes of South America