The Humid Chaco (

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

: ''Chaco Húmedo'' or ''Chaco Oriental'') is tropical grasslands, savannas, and shrublands

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

. It lies in the basin of the Paraná River, covering portions of central

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

and northern

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, and with a small portion of southwestern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and northwestern

Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...

. The natural vegetation is a mosaic of grasslands, palm savanna, and forest.

Geography

The Humid Chaco lies in the lowlands of the Paraná river and its tributaries, including the

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters i ...

. It is bounded on the west by the Dry Chaco, a semi-arid region of dry forests and savannas. The Alto Paraná Atlantic forests lie to the east, and the

Cerrado The ''Cerrado'' (, ) is a vast ecoregion of tropical savanna in eastern Brazil, particularly in the states of Goiás, Mato Grosso do Sul, Mato Grosso, Tocantins, Minas Gerais, and the Federal District. The core areas of the Cerrado biome are the ...

grasslands to the northeast. It borders on some large

flooded grasslands and savannas Flooded grasslands and savannas is a terrestrial biome of the WWF biogeographical system, consisting of large expanses or complexes of flooded grasslands. These areas support numerous plants and animals adapted to the unique hydrologic regimes ...

, including the

Paraná flooded savanna The Paraná flooded savanna (NT0908) is an ecoregion that borders the southern Paraná River in Argentina. It has largely been converted to agriculture or occupied by urban development, but scattered patches of the original habitat remain along the ...

along the lower Paraná and Paraguay rivers, the

Pantanal The Pantanal () is a natural region encompassing the world's largest tropical wetland area, and the world's largest flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and ...

to the north, and the

Southern Cone Mesopotamian savanna The Southern Cone Mesopotamian savanna, also known as the Argentine Mesopotamian grasslands, is a flooded grassland ecoregion of Argentina and southern Paraguay. Setting The ecoregion covers an area of , lying west of the Uruguay River in Argent ...

to the southeast between the Paraná and

rivers. The topography is generally flat or gently rising, and the soils are mostly fine alluvium deposited by the area's rivers. Asuncion, Paraguay's capital, lies in the ecoregion.

Climate

The climate is tropical, becoming subtropical towards the south. Average annual rainfall generally decreases towards the west, and ranges from 1,300 mm in the wetter eastern portions to 750 mm in the west near the transition to the Dry Chaco. Rainfall is highest in the summer months (January to April) and lowest in the winter months (June to August).

Flora

The flora is a mosaic of grassland, savanna, forests, and bogs. Grasslands and savannas are generally found on higher ground, and forests along streams and in river floodplains. Bogs form seasonally or year-round over impermeable soil layers. Grasslands are characterized by tall, coarse grass. Palm savannas are common, including the palm ''

Copernicia alba ''Copernicia alba'' is a South American species of palm tree, which is found in the Humid Chaco ecoregion in Bolivia, Paraguay, Colombia, Brazil (in the states of Mato Grosso and Mato Grosso do Sul) and Argentina (especially the province of ...

''. The most common trees in the forests are quebracho colorado (''

Schinopsis balansae ''Schinopsis balansae'' is a hardwood tree known as willow-leaf red quebracho which forms forests in the subtropical Humid Chaco ecoregion of north-eastern Argentina, and Paraguay. It is also found in the wild Pantanal vegetation in Brazil. Some ...

'') and quebracho blanco (''

Aspidosperma quebracho-blanco ''Aspidosperma quebracho-blanco'', commonly known as Quebracho blanco, kebrako, or white quebracho, is a South American tree species, native to Brazil, northern Argentina, Bolivia, Paraguay, and Uruguay. It must not be confused with other specie ...

''), together with guayacán (''

Caesalpinia paraguariensis ''Libidibia paraguariensis'' (the guayacaú negro or ibirá-berá) is a species of legume in the family Fabaceae. It is found in Argentina, Bolivia, Brazil, and Paraguay. It is threatened by habitat loss. Guayacaú negro is used for timber in ...

''), espina corona ('' Gleditsia amorphoides''), urunday ('' Myracrodruon balansae''), viraró (''

Ruprechtia laxiflora ''Ruprechtia'' is a genus of plant in family Polygonaceae The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus '' Polygon ...

''), palo piedra (''

Diplokeleba floribunda ''Diplokeleba'' is a genus of flowering plants belonging to the family Sapindaceae The Sapindaceae are a family of flowering plants in the order Sapindales known as the soapberry family. It contains 138 genera and 1858 accepted species. Examp ...

''), guayaibí ('' Patagonula americana''), zapallo caspini ('' Pisonia zapallo''), lapacho negro ('' Tabebuia ipe''), palo borracho del flor rosada (''

Chorisia speciosa ''Ceiba'' is a genus of trees in the family Malvaceae, native to tropical and subtropical areas of the Americas (from Mexico and the Caribbean to N Argentina) and tropical West Africa. Some species can grow to tall or more, with a straight, la ...

''), and itin (''

Prosopis kuntzei ''Prosopis kuntzei'' (synonym ''Prosopis casadensis'') is a South American legume, leguminous tree species that inhabits the westernmost Gran Chaco forests covering areas of Argentina, Bolivia, and Paraguay, where it acts as natural component. It ...

'').

Fauna

Native mammals include puma (''Puma concolor''), jaguar (''Panthera onca''),

maned wolf The maned wolf (''Chrysocyon brachyurus'') is a large canine of South America. It is found in Argentina, Brazil, Bolivia, Peru, and Paraguay, and is almost extinct in Uruguay. Its markings resemble those of foxes, but it is neither a fox nor a w ...

(''Chrysocyon brachyurus''),

red brocket The red brocket (''Mazama americana'') is a species of brocket deer from forests in South America, ranging from northern Argentina to Colombia and the Guianas. It also occurs on the Caribbean island of Trinidad (it also occurred on the island ...

(''Mazama americana''),

gray brocket The gray brocket (''Mazama gouazoubira''), also known as the brown brocket, is a species of brocket deer from northern Argentina, Bolivia, southern Peru, eastern and southern Brazil, Paraguay, and Uruguay. It formerly included the Amazonian br ...

(''Mazama gouazoubira''),

marsh deer The marsh deer (''Blastocerus dichotomus'') is the largest deer species from South America reaching a length of and a shoulder height of . It is found in Argentina, Bolivia, Peru, Brazil, Uruguay and Paraguay. Formerly found in much of tropical ...

(''Blastocerus dichotomus''),

pampas deer The Pampas deer (''Ozotoceros bezoarticus'') is a species of deer that live in the grasslands of South America at low elevations.Geist, Valerius. Deer of the world their evolution, behaviour, and ecology'. Mechanicsburg, Pa: Stackpole Books, 1998 ...

(''Ozotoceros bezoarticus''),

White-lipped peccary The white-lipped peccary (''Tayassu pecari'') is a species of peccary found in Central and South America and the only member of the genus ''Tayassu''. Multiple subspecies have been identified. White-lipped peccaries are similar in appearance to ...

(''Tayassu pecari''),

collared peccary The collared peccary (''Dicotyles tajacu'') is a species of artiodactyl (even-toed) mammal in the family Tayassuidae found in North, Central, and South America. It is the only member of the genus ''Dicotyles''. They are commonly referred to as ...

(''Tayassu tajacu''),

giant anteater The giant anteater (''Myrmecophaga tridactyla'') is an insectivorous mammal native to Central and South America. It is one of four living species of anteaters, of which it is the largest member. The only extant member of the genus ''Myrmecophag ...

(''Mymercophaga tridactyla''), capybara (''Hydrochaerys hydrochaeris''),

black howler monkey The black howler (''Alouatta caraya'') or black-and-gold howler, is among the largest New World monkeys and a member of the ''Alouatta'' genus. The black howler is distributed in areas of South America such as Paraguay, southern Brazil, eastern ...

(''Alouatta caraya''), and

Azara’s night monkey Azara's night monkey (''Aotus azarae''), also known as the southern night monkey, is a night monkey species from South America. It is found in Argentina, Bolivia, Brazil, Peru and Paraguay. The species is monogamy, monogamous, with the males prov ...

(''Aotus azarae''). Birds species include the

greater rhea The greater rhea (''Rhea americana'') is a species of flightless bird native to eastern South America. Other names for the greater rhea include the grey, common, or American rhea; ema (Portuguese); or ñandú (Guaraní and Spanish). One of two sp ...

or ñandú (''Rhea americana''),

undulated tinamou The undulated tinamou (''Crypturellus undulatus'') is a species of ground bird found in a wide range of wooded habitats in eastern and northern South America. Etymology Its generic name ''Crypturellus'' is formed from three Latin or Greek words ...

(''Crypturellus undulatus''),

savanna hawk The savanna hawk (''Buteogallus meridionalis'') is a large raptor found in open savanna and swamp edges. It was formerly placed in the genus ''Heterospizias''. It breeds from Panama and Trinidad south to Bolivia, Uruguay and central Argentina ...

(''Buteogallus meridionalis''), and

pale-crested woodpecker The pale-crested woodpecker (''Celeus lugubris'') a species of bird in subfamily Picinae of the woodpecker family Picidae. It is found in Argentina, Bolivia, Brazil, and Paraguay.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A ...

(''Celeus lugubris'').

Protected areas

A 2017 assessment found that 35,949 km², or 12%, of the ecoregion is in protected areas. Protected areas include

Chaco National Park The Chaco National Park ( es, Parque Nacional Chaco) is a national park of Argentina, located in the province of Chaco. It has an area of 150 km2. It was created in 1954 in order to protect a sample of the Eastern Chaco, composed mainly of ...

Río Pilcomayo National Park The Río Pilcomayo National Park ( es, Parque Nacional Río Pilcomayo) is a national park located in the northeastern part of the Argentine province of Formosa, on the border with Paraguay. Established on September 29, 1951 to protect the natur ...

, and Mburucuyá National Park in Argentina, and Ypoá National Park in Paraguay. The

Iberá Wetlands The Iberá Wetlands ( es, Esteros del Iberá, from Guaraní ''ý berá'': "bright water") are a mix of swamps, bogs, stagnant lakes, lagoons, natural slough, and courses of water in the center and center-north of the . Iberá is one of the mos ...

, located in the southeast of the ecoregion adjacent to the

, are protected by Argentina's

Iberá Provincial Reserve The Iberá Provincial Reserve ( es, Reserva Provincial Iberá, from Guaraní ''ý berá'': "bright water") is a provincial protected area in the north-west of Corrientes Province, north-eastern Argentina. Established on 15 April 1983, it contains ...

and Iberá National Park.

References

External links

* {{WWF ecoregion, id=nt0708, name=Humid Chaco La Plata basin Ecoregions of South America Ecoregions of Argentina Ecoregions of Brazil Ecoregions of Paraguay Neotropical ecoregions Tropical and subtropical grasslands, savannas, and shrublands