| 81,000 km²|
Campinarana, or Rio Negro Campinarana is a neotropical ecoregion in the Amazon biome of the north west of Brazil and the east of Colombia that contains vegetation adapted to extremely poor soil. It includes savannah, scrub and forest, and contains many endemic species of fauna and flora.
Campinarana is found in isolated areas of the Rio Negro and Rio Branco basins in the north of Brazil. Patches of campinarana, which may cover several thousand square kilometres, are found in the transitional region from the Guyana Shield to the Amazon basin. Similar vegetation is found in northern Peru, eastern Colombia and south western Venezuela. It is sometimes called "heath forest" or "Rio Negro caatinga". It covers an area of about 31,200 square miles (81,000 km2). None of the ecoregion is protected, but most of it is relatively intact due to its low productivity. Some areas have suffered from cattle grazing, with burning to maintain pasturage.
The soil type determines the ecosystem more than temperature or rainfall. Factors affecting the vegetation are poor drainage, extremely sandy soil, intense leaching and impermeable layers below the surface. Campinarana is typically found on leached white sands around circular swampy depressions in lowland tropical moist forest. The soil is low in nutrients, with highly acidic humus. Temperatures average 24 °C (75 °F). Average rainfall is 2,500 to 3,000 millimetres (98 to 118 in).
Campinarana includes savannah, scrub and forests. The savannah is mainly composed of grasses and lichens, found in the wet plains beside lakes and rivers. The scrub has bare sand, herbaceous plants, shrubs and trees less than 7 metres (23 ft) high. It is found on the sides of the depressions. The forests have trees up to 30 metres (98 ft). They are found higher up. The tree families are different from those found in the humid rain forest that surrounds the Campinarana. Mammals include various species of monkey, bats and rodents. There are fewer species of birds than in other ecoregions of the Amazon biome.