Igapó (Portuguese pronunciation: [igaˈpɔ], from Old Tupi: "root forest") is a word used in Brazil for blackwater-flooded forests in the Amazon biome. These forests and similar swamp forests are seasonally inundated with freshwater. They typically occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found in a range of climate zones, from boreal through temperate and subtropical to tropical. In the Amazon Basin of Brazil, a seasonally whitewater-flooded forest is known as a várzea, which is similar to igapó in many regards; the key difference between the two habitats is in the type of water that floods the forest.[1]

Igapó in Brazil


Igapó is primarily characterized by seasonal inundation caused by abundant rainfall; in some areas, trees can be submerged for up to 6 months of the year.[2] These ecosystems are relatively open and feature over 30% canopy cover with an average canopy height ranging from 20–25 m; sparse measurements of trees can reach 33–36 m. Tree composition includes a varied mixture of leaf types and seasonality. Development of tree communities within the freshwater swamp forests rely heavily on microtopography and flooding intensity. Swamp forests can have harsh environments, in which only a few adapted species are able to sustain life or dominate over other tree species. One of the tree species mostly found in freshwater swamp forests are legume trees, in which most swamp forests have high single legume species populations. Legume trees in these forests are thought to be abundant in nitrogen fixation, which is most common in waterlogged locations and is thought to be a favorable trait when experiencing seasonal and/or constant waterlogging.[3]

Freshwater swamp forests can be classified into two categories of forested wetlands, which are permanently and periodically flooded forests. It is possible to find these two types because of the high microtopographic variation. Due to these topographic differences, tree communities are delimited and have a distribution over small continuous areas.[3]

These forests may be able to sustain a large number of bird, mammal, reptile, amphibian, fish and invertebrate species, however, biodiversity varies between wetland ecosystems and the species richness of the freshwater swamp forests is not entirely known. As for plant species, these forests have a lower diversity compared to other types of forests, such as the terra firme, in South America.[3]

A young guide in Óbidos, Para, Brazil

Soil chemistry

Igapó forests are characterized by sandy acidic soils that have a low nutrient content. The color and acidity of the water is due to the acidic organic humic substances (e.g. tannins) that dissolve into the water. The acidity from the water translates into acidic soils. They are the more nutrient poor than a comparable várzea forest. They also “carry less suspended inorganic elements and contain elevated concentrations of dissolved organic material such as humic and fulvic acids”.[2] Therefore, igapó forests support comparatively less life and the environment found within these areas tend to lack species diversity and animal biomass. Várzea forest soils have high nutrient contents because they receive a transport of high sediment loads from the whitewater rivers. In contrast, igapó forests do not receive this seasonal influx of sediments which explains the nutrient poor soils. However, they do have the highest phosphorus concentrations out of comparable várzea and terra firme forest soils. Nevertheless, the seasonal inundation of the soils leads to anoxic conditions which limits plant growth.[2]


Igapó and other flooded forests typically display a lower diversity of plants than that seen in terra firme forests. Similar to other forests found throughout the tropics, it is common to observe only a few dominant tree species[3] Distribution of trees and other plants is highly dependent on inundation tolerances of species causing a non-random distribution of plants where more flood-tolerant species are found at lower elevations and less flood-tolerant species are found on higher ground. Fabaceae (or Leguminosae) and Euphorbiaceae are the dominant families of plants observed in igapó forest.[2][4]

Seed dispersal

Colossoma macropomum ostergaard
Pacu (Colossoma macropomum), an important food fish and seed predator common in igapó

Tree species adapted to seasonal inundation have adapted to maximize fruit production during periods of flooding in order to take advantage of newly available seed dispersal methods. Fish consume nearly all fruit that fall into the water, and species that are unable to digest the seeds eventually excrete and disperse them into the water. Dispersal by other vectors such as birds and monkeys is secondary to that of fishes in igapó. An important factor in seed survival is the presence of seed predators. Fishes that lack the strong jaws found in characins, such as catfish, digest the fleshy material of the fruit while the seeds pass through the gut unharmed. Because many catfishes are bottom-feeders, they are critical dispersers for seeds that sink upon entering the water.[5]


Giant otter (Pteronura brasiliensis)
Tapirus terrestris
Brazilian tapir (Tapirus terrestrus)

Diversity of terrestrial wildlife and fishes in igapó is highly influenced by flooding. During periods of inundation, vast numbers of aquatic species migrate into the flooded forest in search of food. Fish populations are highest during maximum fruiting periods and river dolphins and giant otters move in to prey upon them.[5] Compared to terra firme forests, Igapó features lower nutrients and favors slow-growing plants with low fleshy fruit production, which has resulted in a lower diversity and abundance of animals.[6] Larger terrestrial mammals have varied strategies of dealing with flooding: red brocket deer and collared peccaries move into islands and shift diet from fruit to browsing woody plants. White-lipped peccaries and tapirs are largely unaffected by seasonal inundation; both species take advantage of the greater abundance of fruit during these times. White-lipped peccaries migrate between flooded and dry areas and tapirs are highly capable swimmers.[7]

Arboreal mammals such as monkeys tend to be lower in species richness compared to terra firme forests due to the decrease in tree diversity and the resulting lack of variety of suitable food types.[4] A lower population density of birds also reflects the lack of nutrients found in igapo forests.[8] For example, within Jaú National Park, 247 species of birds are found in terra firme forests; 121 of those species are limited to that habitat. Within neighboring igapó forests, 194 species of birds are found; of those, just 58 are restricted to igapó.[9]

Human occupation and use

Native Amazonians have been using and modifying the forests in which they have lived for thousands of years. Several studies suggest that the presence of nutrient-rich "black earth" in typically nutrient-poor igapó environments indicates intense fertilization and burning of these areas. Black earth is a modified soil characterized by high nutrient content from highly stable organic matter and high levels of phosphorus. The highly fertile soils and the openness of these areas confirm that the native Amazonians have been using these fields for agriculture.[10]

However, the Amazonians have not only used these areas for crops; they have used their agricultural lands as a place to hunt as well. Many animals (rodents, tapirs and deer) are attracted to these areas for food. The Amazonians produce a surplus so that the animals do not over-consume their food resource. Though, if the animals do start to deplete their crops, they will then harvest higher numbers of animals. Additionally, Amazonians consume fish as a main source of protein. Indigenous peoples understand that, while flooded, the forest serves as an essential feeding ground that increases fish abundance. Because of this, many protect igapó forests from deforestation.[11]


The greatest threat to igapó forests is the construction of hydroelectric dams on tributaries of the Amazon river; when constructed, the dams will divert huge amounts of water and dramatically change the hydrology of the Amazon basin and its ecosystems. Because many flora within seasonally inundated forests are highly adapted to a particular flooding schedule, alterations in flood patterns and the creation of permanently flooded areas will induce higher rates of tree mortality. The loss of these trees will likely affect populations of frugivorous understory birds, such as the blue-throated piping guan and some Amazona parrots that are restricted to igapó. Loss of habitat will cause migrations of species that will inevitably lead to higher competition in unaffected habitats and possibly local extinctions.[12]

Pipile cumanensis (Denver Zoo)2
Blue-throated piping guan (Pipile cumanensis), one of the species likely to be affected by hydroelectric dams

Deforestation is also a large conservation concern because Igapó forests are characterized by slow tree growth due to low soil nutrient content and high soil acidity. Despite low nutrient availability, Igapó and other floodplain forests can be biodiverse with some partially endemic species. Due to soil chemistry and seasonal inundation, trees and other resources tend to grow back more slowly after harvest by humans than in other types of Amazonian forests, . Accordingly, igapó forests cannot sustain timber harvest. For the future, igapó forests should be fully protected from logging and deforestation because of the low productivity found in them.[13]

In protected areas, such as Jaú National Park, the lack of indigenous inhabitants and a low population of rural families limits the potential for over-harvest of fish and turtle species. However, enforcement of harvest regulation is problematic when there are only three park rangers at the entrance to the park. In other unprotected areas that lack rangers, unregulated harvest of fauna by peoples that move into igapó forests to hunt and fish may adversely affect future stocks.[9] Approximately 3% of the Amazon's seasonally inundated forests are under protection within national parks or biological reserves.[12]

Notable areas

Freshwater swamp forests are distributed in multiple climate zones throughout the world, such as boreal, temperate, tropical and subtropic zones. They are found in the Afrotropics, Australasia, Indomalaya, and the Neotropics. However, they are most notably found in Amazonian areas.

Igapó forests are one of the distinct natural communities found in the Cantão State Park. They offer a rich bird fauna that includes some habitat specialists due to the unique ecosystem the blackwater inundation provides. The trees in the igapó bloom once the inundation season begins. They do this so they can drop their fruit into the water to be dispersed by the different fish taxa.[9]

The Jaú National Park was designated in 1980 and is the largest national park in the Amazon Basin and the second largest protected tropical forest. It is known for its high level of biodiversity and varying ecosystems within. The park protects the entire watershed of the Jaú River, which happens to be one of the best examples of a blackwater ecosystem where the water is colored by acidic decomposing organic matter.[9]


  1. ^ Fresh water flooded forests
  2. ^ a b c d Haugaasen, Torbjørn and Peres, Carlos Augusto. Floristic, edaphic and structural characteristics of flooded and unflooded forests in the lower Rio Purús region of central Amazonia, Brazil. Acta Amaz. [online]. 2006, vol.36, n.1, pp. 25-35 <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672006000100005&lng=en&nrm=iso>.
  3. ^ a b c d Koponen, Piia, Pekka Nygren, et al. "Tree Species Diversity and Forest Structure in Relation to Microtopography in a Tropical Freshwater Swamp Forest in French Guiana." Plant Ecology. 173.1 (2004): 17-32. <https://www.jstor.org/stable/20146617.>.
  4. ^ a b Parolin, P., J. Adis, et al. "Floristic study of an igapó floodplain forest in Central Amazonia, Brazil (Tarumã-Mirim, Rio Negro)." Amazoniana. XVII.1/2 (2004): 29-47. <http://www.evolbio.mpg.de/amazoniana/18_03Parolin.pdf>.
  5. ^ a b Kubitzki, Klaus, and Albrecht Ziburski. "Seed Dispersal in Flood Plain Forests of Amazonia." Biotropica. 26.1 (1994): 30-43. <https://www.jstor.org/stable/2389108>.
  6. ^ Fleagle, J. G.; Janson, Charles; and Reed, Kaye. Primate Communities. Cambridge University Press, 1999. Cambridge Books Online. doi:10.1017/CBO9780511542381
  7. ^ Bodmer, Richard E. "Responses of Ungulates to Seasonal Inundations in the Amazon Floodplain." Journal of Tropical Ecology. 6.2 (1990): 191-201. <https://www.jstor.org/stable/2559266>.
  8. ^ Haugaasen, Torbjørn, and Carlos A. Peres. "Population abundance and biomass of large-bodied birds in Amazonian flooded and unflooded forests." Bird Conservation International. 18.2 (2008): 87-101. <http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1878112>.
  9. ^ a b c d United Nations Environment Programme-World Conservation M. "Jaú National Park, Brazil." Jaú National Park, Brazil. The Encyclopedia of Earth, 17 Nov. 2008. <http://www.eoearth.org/article/Ja%C3%BA_National_Park,_Brazil>.
  10. ^ German, Laura A (2004). "Ecological Praxis and Blackwater Ecosystems: A Case Study From the Brazilian Amazon". Human Ecology. 32 (6): 653–83. doi:10.1007/s10745-004-6831-1.
  11. ^ Dufour, Darna L. "Use of Tropical Rain Forests by Native Amazonians." BioScience 40.9 (1990): 652–59. JSTOR. University California Press, Oct. 1990.<https://www.jstor.org.lp.hscl.ufl.edu/stable/pdfplus/1311432.pdf?acceptTC=true>.
  12. ^ a b Borges, Sergio Henrique, and Andre Carvalhaes. "Bird species of black water inundation forests in the Jaú National Park (Amazonas state, Brazil): their contribution to regional species richness." Biodiversity and Conservation. 9. (2000): 201-214. <http://www.springerlink.com/content/t4j15m7157521657/>.
  13. ^ Ferreira Da Fonseca Júnior, Sinomar, Maria Teresa Fernandez Piedade, and Jochen Schöngart. "Wood Growth of Tabebuia Barbata (E. Mey.) Sandwith (Bignoniaceae) and Vatairea Guianensis Aubl. (Fabaceae) in Central Amazonian Black-water (igapó) and White-water (várzea) Floodplain Forests." Trees 23.1 (2009): 127-34. <http://www.springerlink.com/content/4001k74g64np0721/>.

See also

António Filipe Camarão

António Filipe Camarão (c. 1580 – August 24, 1648) was an indigenous Brazilian from the tribe of the Potiguara near the Rio Grande do Norte area of the Portuguese colony of Brazil. His original tribal name was Poti, which means prawn (Portuguese Camarão). He was born in the neighbourhood of Igapó, in Natal, or, according to some other historians, in the state of Pernambuco, or in Aldeia Velha.

On the occasion of his conversion to the Christian faith on June 13, 1612 (the feast day of Saint Anthony) he chose the Portuguese version of the name António and the middle name of Filipe in honor of King Philip II of Portugal, adding the Portuguese version of his tribal name Poti (Camarão in Portuguese). He married the very next day in the Capela de São Miguel de Guajeru to a lady from his tribe who also converted to Christianity and took the name Clara. Besides knowing perfect Portuguese, he was also well-versed in Latin because of his education in a missionary school led by Jesuit monks.

Since 1630, he fought against the Dutchmen, who tried to take over Brazil. He fought them as the leader of an Indian regiment on various battles until his death in 1648. The last year of his life brought him to the top of his military career as leader of the right flank of the United Portuguese Army during the First Battle of Guararapes against General Arcizewski.

By royal decision, António Filipe Camarão was given the right to use the title "Dom". He was also a knight commander of the Order of Christ, the most prestigious order of Portugal. He is buried in Várzea in Pernambuco, Brazil on August 24, 1648.

There are several ways of writing the name. In Brazil, for example, it is common to read the name in the archaic spelling "Felipe Camarão" or "Antônio Felipe Camarão".


Beruri is a municipality located in the Brazilian state of Amazonas. Its population was 13,220 (2005) and its area is 17,251 km².The municipality contains 28.17% of the 1,008,167 hectares (2,491,230 acres) Piagaçu-Purus Sustainable Development Reserve, established in 2003.

It contains about 6% of the Nascentes do Lago Jari National Park, an 812,745 hectares (2,008,340 acres) protected area established in 2008.

It contain 57% of the 397,557 hectares (982,380 acres) Igapó-Açu Sustainable Development Reserve, created in 2009.

Borba, Amazonas

Borba is a municipality in the state of Amazonas in northern Brazil.


Cantão is a tropical forest ecosystem located in the central Araguaia river basin, the southeastern edge of the Amazon biome, in the Brazilian state of Tocantins. It is one of the biologically richest areas of the eastern Amazon, with over 700 species of birds, nearly 300 species of fish (more than in all of Europe), and large populations of endangered species such as the giant otter and the black cayman. About 90% of the Cantão ecosystem is protected within Cantão State Park.

Cantão State Park

The Cantão State Park (Portuguese: Parque Estadual do Cantão) is a state park in the state of Tocantins, Brazil.

It protects the Cantão wetlands, an area of igapó flooded forest in the ecotone where the Amazon rainforest merges into the cerrado.

Caquetá moist forests

The Caquetá moist forests (NT0107) is an ecoregion of tropical moist broad leaf forest to the east of the Andes in the east of Colombia, with a small section in Brazil, in the Amazon biome.

The forests are in the transition between the Guiana and Amazon regions, and have highly diverse flora and fauna.

They are relatively intact, although they are mostly unprotected and are threatened with deforestation to create cattle pastures.

Freshwater swamp forest

Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found in a range of climate zones, from boreal through temperate and subtropical to tropical.

In the Amazon Basin of Brazil, a seasonally flooded forest is known as a várzea, a use that now is becoming more widespread for this type of forest in the Amazon (though generally spelled varzea when used in English). Igapó, another word used in Brazil for flooded Amazonian forests, is also sometimes used in English. Specifically, varzea refers to whitewater-inundated forest, and igapó to blackwater-inundated forest.

Peat swamp forests are swamp forests where waterlogged soils prevent woody debris from fully decomposing, which over time creates a thick layer of acidic peat.


The Guasiniidae are a family of harvestman with three described species from South America.

It is, together with the Fissiphalliidae and the Ogoveidae, one of the least diverse harvestman families.

The family is probably closely related to the Zalmoxidae and Fissiphalliidae.

All described species in this family are completely eyeless (anophthalmic).

González-Sponga found the two first species inside bark under litter, G. persephone was also found inside soil, in an inundation-forest of black-water (igapó) at Tarumã-Mirim, near the mouth of Rio Negro, 20 km upstream from Manaus. The region is flooded for almost half a year.

Current research suggests that the two described genera should be merged into one.

Igapó-Açu River

Igapó-Açu River (Portuguese: Rio Igapó-Açu is a river of Amazonas state in north-western Brazil.

It is a left tributary of the Madeira River.

The river flows through the Purus-Madeira moist forests ecoregion.

Igapó-Açu Sustainable Development Reserve

The Igapó-Açu Sustainable Development Reserve (Portuguese: Reserva de Desenvolvimento Sustentável Igapó-Açu) is a sustainable development reserve in the state of Amazonas, Brazil. It is part of a "green barrier" created to prevent deforestation along the BR-319 highway.

Igapó River

The Igapó River is a river of Paraná state in southern Brazil.


Ipueira is a municipality in the interior of the state of Rio Grande do Norte in the Northeast region of Brazil, in the region of Seridó. It is located 318 kilometers to the southwest of Natal, the state capital, and has an area of 127 km2 and is located at the midway point between Caicó (in Rio Grande do Norte) and Patos (in Paraiba). It has a population (as estimated in 2016 by IBGE in 2016) of 2,236 people, making it the third least populous municipal in the state.

Ipueira was separated from the municipality São João do Sabugi in the 1960's. The name is formed from combining the words iapo (meaning igapó) with the Portuguese suffix -eira. It has a human development index of 0.679 (2010), the eighth highest in Rio Grande do Norte, and considered average by the United Nations Development Programme.

List of rivers of Amazonas (Brazilian state)

List of rivers in Amazonas (Brazilian State).

The list is arranged by drainage basin, with respective tributaries indented under each larger stream's name and ordered from downstream to upstream. Amazonas is located entirely within the Amazon Basin.

List of rivers of Paraná

List of rivers in Paraná (Brazilian State).

The list is arranged by drainage basin from north to south, with respective tributaries indented under each larger stream's name and ordered from downstream to upstream. All rivers in Paraná drain to the Atlantic Ocean, primarily via the Paraná River.


Manicoré is a municipality located in the south-east of the Brazilian state of Amazonas.

Matupiri River

The Matupiri River (Portuguese: Rio Matupiri) is a river of Amazonas state in north-western Brazil.

It is a tributary of the Igapó-Açu River.

Mura people

The Muras are an indigenous people who live in the central and eastern parts of Amazonas, Brazil, along the Amazon river from the Madeira to the Purus. They played an important part in Brazilian history during colonial times and were known for their quiet determination and subsequent resistance to the encroaching Portuguese culture. Formerly a powerful people, they were defeated by their neighbors, the Munduruku, in 1788.Of the original diversity of Muran languages, only Pirahán survives today.

Newton Navarro Bridge

The Newton Navarro Bridge, is one of the biggest cable-stayed bridges in Brazil. It is located in the city of Natal, the capital of the Brazilian state of Rio Grande do Norte. It connects North Zone and the cities of the north coast to the South Zone and the other regions of the city that cross the Potengi River.

The main purpose is to ease the usual heavy traffic on Igapó Bridge and to improve access to the future Greater Natal International Airport and its adjacent areas. It also increases the flow of tourism on the north coast and improves access to the inhabitants of the North Zone to the downtown and the main zones.

It is named upon Newton Navarro, an important local artist.

Yellow-crowned brush-tailed rat

The yellow-crowned brush-tailed rat, Isothrix bistriata, is a South American brush-tailed rat species from the family Echimyidae. It is found in Bolivia, Brazil, Colombia, Ecuador and Peru and Venezuela.They are nocturnal and arboreal animals found in lowland evergreen rainforest, probably restricted to igapó and várzea habitats. Sometimes they can be seen at the entrances of their dens, in tree holes (specially hollow palms) on the borders of rivers.

Classification systems

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