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Pantanal

earth science Maturity 7-9 Next article →

The Pantanal is a massive natural region that serves as the world's largest tropical wetland area. It also contains the largest expanse of flooded grasslands on Earth. This vast landscape spans an estimated 140,000 to 240,000 square kilometers. While most of the region lies within the Brazilian state of Mato Grosso do Sul, it also extends into Mato Grosso, Bolivia, and Paraguay. The name "Pantanal" is derived from Portuguese and Spanish words meaning swamp or marsh. The suffix "-al" indicates an abundance or a large collection of these features.

Pantanal, Mato Grosso, Brasil
Pantanal, Mato Grosso, Brasil

Geologically, the Pantanal is a large, concave depression in the Earth's crust. This formation is related to the Andean orogeny, which is the process of mountain building in the Andes. The region acts as an enormous internal river delta. Water from the surrounding Planalto highlands runs off into this gently sloped basin. The water eventually exits the system through the Paraguay River and its various tributaries. Because the land is so flat, the floodwaters move very slowly, at only about 0.1 meters per second. This slow movement is caused by the low gradient and the resistance of dense vegetation.

The ecosystem is defined by a cycle of seasonal inundation and desiccation. This means the land shifts between being flooded and being dry. During the rainy season, roughly 80% of the Pantanal floodplains are submerged. This flooding is driven by annual rainfall that typically ranges between 920 and 1,540 mm. In the Paraguay River portion, water levels can rise by two to five meters each season. When rising waters first touch dry soil, the environment can become anoxic. Anoxic means the water is depleted of oxygen. This can lead to natural fish kills if there are no oxygenated refuges available for them.

The vegetation in the region is known as the "Pantanal complex." It is a mixture of many different plant communities from surrounding areas. These include plants from the Amazonian rainforest, the Cerrado savannas, and the Chaco savannas. Forests usually grow at higher altitudes, while grasslands cover the areas that flood seasonally. There are approximately 2,000 different identified plants in this biome. Two major factors limit how these plants grow: the seasonal flooding and the water stress during the dry season.

Aerea
Aerea

This environment supports an incredible variety of wildlife. The Pantanal is home to 463 species of birds and 269 species of fish. It also supports more than 236 species of mammals and 141 species of reptiles and amphibians. There are over 9,000 subspecies of invertebrates living here. One vital animal is the apple snail, a keystone species. A keystone species is an organism that helps hold an entire ecosystem together. When plants decay in the water, they use up the oxygen. The apple snail uses both gills and lungs to survive. It extends a snorkel to the surface to breathe, allowing it to eat dead matter and turn it into nutritious fertilizer.

The region is famous for its high concentration of specific animals. For example, there were 10 million yacare caimans recorded in 1996. This is the highest concentration of crocodilians in the world. The Pantanal also hosts one of the largest and healthiest jaguar populations on Earth. However, some animals are quite rare or endangered. The marsh deer and the giant river otter are among the rarest inhabitants. Other threatened species include the hyacinth macaw, the maned wolf, and the giant anteater. Many birds, such as herons and kingfishers, use the wetlands as breeding grounds.

Despite its beauty, the Pantanal faces many significant threats. About 99% of the land is privately owned for agriculture and ranching. There are roughly 2,500 fazendas, or farms, and up to eight million cattle in the region. This ranching can cause erosion and change the soil. Additionally, the use of chemical pesticides and fertilizers in large-scale soy farming can leach into the water. In late 2020, a massive fire destroyed about 12,500 square kilometers of the wetland. This fire was attributed to climate change and killed millions of vertebrates. Protecting this area through sites like the Pantanal Matogrossense National Park is essential for its survival.

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File:Pantanal, Mato Grosso, Brasil.jpg
Pantanal, Mato Grosso, Brasil.jpg
File:Aerea.jpg
Aerea.jpg
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