Campinarana (NT0158, ), also called Rio Negro Campinarana, is a

neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

ecoregion in the Amazon biome of the north west of

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, southern

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

, and the east of

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

that contains vegetation adapted to extremely poor soil. It includes savanna, scrub and forest, and contains many endemic species of fauna and flora.

Location

Areas of campinarana, which may cover several thousand square kilometres, are found in the transitional region from the Guyana Shield to the Amazon basin. Large stretches of Campinarana are contained within the Japurá-Solimões-Negro moist forests, Negro-Branco moist forests, Guianan piedmont and lowland moist forests, Uatuma-Trombetas moist forests and Guianan savanna. The campinarana ecoregion totals about . Campinarana is mainly found in flat flooded areas in the Rio Negro and Rio Branco basins, which are tributaries of the Amazon, in northern Brazil along the borders of Colombia and Venezuela, and in the Ventuari–upper

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

basin in Venezuela's southernmost state of Amazonas. Smaller patches are found throughout the Amazon region. Areas of white-sand soils and their characteristic campinarana vegetation are found in the Serra do Cachimbo on the

Pará Pará () is a Federative units of Brazil, state of Brazil, located in northern Brazil and traversed by the lower Amazon River. It borders the Brazilian states of Amapá, Maranhão, Tocantins (state), Tocantins, Mato Grosso, Amazonas (Brazilian st ...

–

Mato Grosso Mato Grosso ( – ) is one of the states of Brazil, the List of Brazilian states by area, third largest by area, located in the Central-West Region, Brazil, Central-West region. The state has 1.66% of the Brazilian population and is responsible ...

boundary, the Parecis plateau in

Rondônia Rondônia () is one of the 26 states of Brazil, located in the northern subdivision of the country (central-western part). It is bordered by Acre (state), Acre in the west, Amazonas, Brazil, Amazonas in the north, Mato Grosso in the east, and Bo ...

, the Atlantic coast near the mouth of the Amazon, and in

Maranhão Maranhão () is a States of Brazil, state in Brazil. Located in the country's Northeast Region, Brazil, Northeast Region, it has a population of about 7 million and an area of and it is divided into 217 municipalities. Clockwise from north, it ...

. Similar vegetation is found in northern Peru, eastern Colombia and south western Venezuela.

Climate

Temperatures in the region average and average rainfall is .

Soil characteristics

Tropical soils are generally infertile, and white sand soils are among the most infertile of such soils, primarily composed of quartz sand. The white sands are found on arenaceous sediments on the low ''terra firme'' uplands, on natural levees in a flooded Várzea forest, on restinga sand dunes in a coastal lowland, on

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

sandstone plateaus and on hill areas of granitic rocks. 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. 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. They had a thick humus layer, a highly leached A horizon, and a well developed Bh horizon at . 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. They may be short of phosphorus and/or calcium. The water that drains the Campinarana is tea colored, often called blackwater. The low exchange capacity of the podzols lets decomposing organic matter dissolve in soil water as

humic acid Humic substances (HS) are colored relatively recalcitrant organic compounds naturally formed during long-term decomposition and transformation of biomass residues. The color of humic substances varies from bright yellow to light or dark brown lead ...

s, from where it is carried into the nearby streams.

Ecology

Flora

Campinarana has very varied vegetation formations from fields to forests with thin trees. The

sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short Internode (botany), internodes (the distance between leaves along the stem) and leaf orientation which is parallel or ...

ous vegetation is adapted to the sandy soil, with high endemism and low diversity. Campinarana vegetation includes

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) biome and ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach th ...

, scrub and forests. The

Brazilian Institute of Geography and Statistics The Brazilian Institute of Geography and Statistics (; IBGE) is the agency responsible for official collection of statistical, geographic, cartographic, geodetic and environmental information in Brazil. IBGE performs a decennial national cen ...

defines four subtypes, or formations, of vegetation: The forests are found higher up. They have trees up to from families that differ from those in the humid rain forest that surrounds the Campinarana. The scrub has bare sand, herbaceous plants, shrubs and trees less than high. The palm '' Barcella odora'' is endemic. It is found on the sides of the depressions. The savannah is mainly composed of grasses and lichens, found in the wet plains beside lakes and rivers.

Fauna

Fauna are less diverse in the campinarana than in the surrounding ecoregions. 153 species of mammals have been reported. Mammals with restricted distribution include white-faced saki (''Pithecia pithecia''), golden-backed uakari (''Cacajao melanocephalus''), red-faced spider monkey (''Ateles paniscus''), mottle-faced tamarin (''Saguinus inustus''), Isabelle's ghost bat (''Diclidurus isabella''), Marinkelle's sword-nosed bat (''Lonchorhina marinkellei''), least big-eared bat (''Neonycteris pusilla''), Ega long-tongued bat (''Scleronycteris ega''), Brock's yellow-eared bat (''Vampyriscus brocki''), yellow-throated squirrel (''Sciurus gilvigularis''), northern grass mouse (''Necromys urichi''), black-tailed hairy dwarf porcupine (''Coendou melanurus'') and Tome's spiny rat (''Proechimys semispinosus''). Other mammals include

collared peccary The collared peccary (''Dicotyles tajacu'') is a peccary, a species of artiodactyl (even-toed) mammal in the family Peccary, Tayassuidae found in North America, North, Central America, Central, and South America. It is the only member of the gen ...

(''Pecari tajacu''), white-lipped peccary (''Tayassu pecari''), South American tapir (''Tapirus terrestris''),

jaguar The jaguar (''Panthera onca'') is a large felidae, cat species and the only extant taxon, living member of the genus ''Panthera'' that is native to the Americas. With a body length of up to and a weight of up to , it is the biggest cat spe ...

(''Panthera onca'') and red brocket (''Mazama americana''). Endangered mammals include white-bellied spider monkey (''Ateles belzebuth''), black bearded saki (''Chiropotes satanas''), Fernandez's sword-nosed bat (''Lonchorhina fernandezi''), Marinkelle's sword-nosed bat (''Lonchorhina marinkellei'') and

giant otter The giant otter or giant river otter (''Pteronura brasiliensis'') is a South American carnivorous mammal. It is the longest member of the weasel family, Mustelidae, a globally successful group of predators, reaching up to . Atypical of mustel ...

(Pteronura brasiliensis). 368 species of birds have been recorded, fewer than in the surrounding forest. Endemic species include Rio Branco antbird (''Cercomacra carbonaria''), spot-backed antwren (''Herpsilochmus dorsimaculatus''), chestnut-crested antbird (''Rhegmatorhina cristata'') and Orinoco piculet (''Picumnus pumilus''). Species with restricted distribution include russet-backed oropendola (''Psarocolius angustifrons''), white-bellied dacnis (''Dacnis albiventris''), dotted tanager (''Tangara varia''), Serra do Mar tyrant-manakin (''Neopelma chrysolophum''), yellow-crested manakin (''Heterocercus flavivertex'') and crestless curassow (''Mitu tomentosum''). Endangered birds include Rio Branco antbird (''Cercomacra carbonaria'') and yellow-bellied seedeater (''Sporophila nigricollis'').

Status

The

World Wildlife Fund The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the ...

classes the ecoregion as "Relatively Stable/Intact". 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.

References

Bibliography

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