The Pantanal is a natural region encompassing the world’s largest tropical wetland area. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and portions of Bolivia and Paraguay. It sprawls over an area estimated at between 140,000 and 195,000 sq kms – 54,000 and 75,000 sq mls. Various sub-regional ecosystems exist, each with distinct hydrological, geological and ecological characteristics. Roughly 80% of the Pantanal floodplains are submerged during the rainy seasons, nurturing an astonishing biologically diversity of aquatic plants that, in turn support a terrific range of fauna, especially birds.
It consists of a huge, gently-sloped basin that receives runoff from the upland areas (the Planalto highlands) and slowly releases the water through the Paraguay River and its tributaries. It constitutes an enormous internal river delta (like the smaller similar Okavango Delta in Africa), in which several rivers flowing from the surrounding plateau merge, depositing their sediment residues, which have been filling, throughout the years, the large depression.
Pantanal ©Sara Jenner Wildfoot
The Pantanal is bounded by the Chiquitano dry forests to the west and northwest, by the Arid Chaco dry forests to the southwest, and the Humid Chaco to the south. The Cerrado savannas lie to the north, east and southeast. The Pantanal has an average yearly rainfall of 39 to 55 inches, but is fed by the upper Paraguay River. Its average temperature is 25 °C (77 °F), but temperatures can fluctuate from 0 to 40 °C (32 to 104 °F).
Green Ibis Mesembrinibis cayennensis ©Sara Jenner Wildfoot
During the rainy season, the water in the Pantanal basin rises between two and five meters. Just as the Nile delta is fertile, arable land, so too are the Pantanal plains. The dramatic increase of water during the rainy season nourishes the land. Humans have taken advantage of this so much that it has become a problem.
Blue-and-gold Macaw Ara ararauna ©Sara Jenner Wildfoot
The vegetation of the Pantanal, often referred to as the “Pantanal complex”, is a mixture of plant communities typical of a variety of surrounding biome regions: these include moist tropical Amazonian rainforest plants, semiarid woodland plants typical of northeast Brazil, Brazilian cerrado savanna plants and plants of the Chaco savannas of Bolivia and Paraguay. Forests usually occur at higher altitudes of the region, while grasslands cover the seasonally inundated areas. The key limiting factors for growth are inundation and, even more importantly, water-stress during the dry season. The Pantanal ecosystem is home to 3,500 known plant species. It is also thought to be home to 1,000 bird species, 400 fish, 300 mammals, 480 reptiles and over 9,000 different subspecies of invertebrates.
The apple snail is a keystone species in its ecosystem. When the wetlands are flooded once a year, the grass and other plants will eventually die and start to decay. During this process, decomposing microbes deplete the shallow water of all oxygen, suffocating larger decomposers. Unlike other decomposing animals, the apple snail have both gills and lungs, making it possible for them to thrive in anoxic waters where they recycle the nutrients. To get oxygen they extend a long snorkel to the water surface and pump air into their lungs. This ability allows them to consume all the dead plant matter and turning it into nutritious fertilizer available for the plants in the area. The snails themselves are also food for a variety of animals.
Giant Otter Pteroneura brasiliensis ©Sara Jenner Wildfoot
Among the rarest animals to inhabit the wetland of the Pantanal are the marsh deer Blastocerus dichotomus and the giant river otter Pteroneura brasiliensis. Parts of the Pantanal are also home to other endangered or threatened species including Hyacinth Macaw Anodorhyncus hyacinthinus, the maned wolf Chrysocyon brachyurus, South American tapir Tapirus terrestris and giant anteater Myrmecophaga tridactyla.
Common species include Capybara Hydrochoerus hydrochaeris and Yacare Caiman Caiman yacare. According to 1996 data, there were 10 million caimans in the Pantanal making it the highest concentration of crocodilians in the World. In addition to caiman other reptiles that inhabit the Pantanal include the Yellow Anaconda Eunectes notaeus and the Green Iguana Iguana iguana.
Jaguar Panthera onca ©Sara Jenner Wildfoot
The Pantanal is home to one of the largest and healthiest jaguar Panthera onca populations on Earth.
Text Source: Fatbirder
Photo Source: Wildfoot
Map Source: Google Maps