Humid Chaco
The Humid Chaco (Spanish: Chaco Húmedo or Chaco Oriental) is tropical grasslands, savannas, and shrublands ecoregion in South America. It lies in the basin of the Paraná River, covering portions of central Paraguay and northern Argentina, and with a small portion of southwestern Brazil and northwestern Uruguay. 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. 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 grasslands to the northeast. It borders on some large flooded grasslands and savannas, including the Paraná flooded savanna along the lower Paraná and Paraguay rivers, the Pantanal to the north, and the Southern Cone Mesopotamian savanna to the southeast between the Paraná and Uruguay 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