Cerrado

The Cerrado is a massive tropical savanna located in central Brazil.

It is the second largest habitat type in Brazil, following the Amazonian rainforest. This vast ecoregion covers 21 percent of the country's total land area. It extends across many states, including Goiás, Mato Grosso, and Minas Gerais. The region also reaches marginally into Paraguay and Bolivia. It covers about 2 million square kilometers of land. Because about 75 percent of this area is privately owned, protecting it is difficult.

The climate of the Cerrado is characterized by a semi-humid tropical pattern. The year is divided into two dominant seasons: wet and dry. Most of the area receives between 80 and 200 cm of annual precipitation. A very strong dry season occurs during the southern winter from April to September. The average annual temperatures range between 22 and 27 °C. These seasonal shifts create a shifting mosaic of different habitats. This variety of environments supports a huge range of life.

Vegetation in the Cerrado varies based on how much canopy cover exists. Researchers have categorized these into four distinct types. The first is campo sujo, which has a herbaceous layer and small trees about 3 meters tall. Next is campo cerrado, where trees average about 4 meters in height. The third type is cerrado sensu stricto, featuring orchard-like vegetation with 6-meter trees. Finally, cerradão has a canopy cover near 50 percent with trees reaching 9 meters.

Other important habitats include gallery forests and savanna wetlands. Gallery forests are closed canopy tall forests that grow along streams. Between these forests and the savanna lies the wet campo. In the wet campo, tree growth is inhibited by seasonal changes in the water table. Soil also plays a critical role in shaping the landscape. Most soils are oxisols, which are well-drained but have low pH levels. They also lack calcium and magnesium, though nitrogen and phosphorus levels can affect tree growth.

The Cerrado is one of the most biologically diverse savannas on Earth. The World Wide Fund for Nature calls it the biologically richest savanna in the world. It contains about 10,000 plant species and 837 bird species. There are nearly 200 species of mammals and 150 amphibian species. Many species are endemic, meaning they are found nowhere else. For example, 10 bird species and 11 mammal species are unique to this region.

Animals have developed specific ways to live in this environment. Fire is a natural part of the landscape and shapes the vegetation. Many plants are fire-adapted and possess thick, corky bark to survive heat. Mammals often use gallery forests as primary habitats for protection and water. Large predators like the jaguar and cougar live here, alongside herbivores like the Brazilian tapir. Insects are also vital, especially leaf cutter ants. These ants can reach densities of 4,000 nests per hectare.

Historically, the Cerrado's vegetation may date back to the Cretaceous period. It likely expanded and contracted alongside the Amazonian rainforest during glacial periods. This movement created different biological refugia that boosted species richness. Early indigenous groups, such as the Xavantes and Karajás, used fire as a tool. They used it to increase fodder for domesticated animals. Later, the Danish botanist Eugenius Warming provided the first detailed European account in 1892.

The Cerrado is also a vital resource for South American water. It contains the headwaters for the Paraná-Paraguay and São Francisco river basins. Additionally, it feeds major Amazon tributaries like the Xingu and Tapajós. The region also acts as a potent carbon sink in its peatlands. This carbon storage is six times more potent per unit area than the Amazon. However, agricultural expansion has changed the land significantly.

In the mid-1960s, agricultural activity began to increase rapidly. Initially, the low-fertility soil was only used for beef cattle. This changed when researchers at Embrapa discovered how to improve the soil. By adding lime and phosphorus, the land became suitable for industrial crops. In 2003 and 2004, about 25 million tons of lime were used. This allowed for a massive boom in soybean production. Today, Brazil is a leading global exporter of soybeans due to this development.