Areas of campinarana, which may cover several thousand square kilometres, are found in the transitional region from the Guyana Shield to the Amazon basin.

[5] Areas of white-sand soils and their characteristic campinarana vegetation are found in the Serra do Cachimbo on the Pará–Mato Grosso boundary, the Parecis plateau in Rondônia, the Atlantic coast near the mouth of the Amazon, and in Maranhão.

[3] Factors affecting the vegetation are poor drainage, extremely sandy soil, intense leaching and impermeable layers below the surface.

[7] Campinarana is typically found on leached white sands around circular swampy depressions in lowland tropical moist forest.

[2] A study at San Carlos de Río Negro, near the confluence of the Guainia and Casiquiare rivers in southern Venezuela, found the soils were similar to temperate podzols.

Tropical rainfall over millions of years had intensely leached the soils, which had become infertile due to lack of a source of fresh parent material.

The low exchange capacity of the podzols lets decomposing organic matter dissolve in soil water as humic acids, from where it is carried into the nearby streams.

[2] Endangered birds include Rio Branco antbird (Cercomacra carbonaria) and yellow-bellied seedeater (Sporophila nigricollis).