The Purus-Madeira moist forests (NT0157) is an

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

in the central

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

. It is part of the

Amazon biome The Amazon biome () contains the Amazon rainforest, an area of tropical rainforest, and other ecoregions that cover most of the Amazon basin and some adjacent areas to the north and east. The biome contains blackwater river, blackwater and whitewa ...

. The ecoregion covers a stretch of flat and relatively infertile land between the Purus and

Madeira Madeira ( ; ), officially the Autonomous Region of Madeira (), is an autonomous Regions of Portugal, autonomous region of Portugal. It is an archipelago situated in the North Atlantic Ocean, in the region of Macaronesia, just under north of ...

rivers, extending to the

Solimões River Solimões () is the name often given to upper stretches of the Amazon River in Brazil from its confluence with the Rio Negro upstream to the border of Peru. The Solimões flows for about 1,600 km (1,000 miles) through a floodplain about 80 km ...

(upper Amazon) in the north. It is isolated from other regions by the seasonally flooded

várzea forest A várzea forest is a seasonal floodplain forest inundated by whitewater rivers that occurs in the Amazon biome. Until the late 1970s, the definition was less clear and várzea was often used for all periodically flooded Amazonian forests. Althoug ...

along these rivers, and has a high degree of

endemism Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

among its flora and fauna. The natural environment is relatively intact. The

BR-319 BR-319 is an federal highway that links Manaus, Amazonas to Porto Velho, Rondônia. The highway runs through a pristine part of the Amazon rainforest. It was opened by the military government in 1973 but soon deteriorated, and by 1988 was imp ...

highway was built along the length of the ecoregion in the early 1970s, but rapidly deteriorated and is now closed.

Location

The Purus-Madeira moist forests ecoregion lies to the east of the Carauari arch, an ancient uplift zone in Brazil. The ecoregion stretches from southwest to northeast between the

Purus River The Purus River (Portuguese: ''Rio Purus''; Spanish: ''Río Purús'') is a tributary of the Amazon River in South America. Its drainage basin is , and the mean annual discharge is . The river shares its name with the Alto Purús National Park a ...

to the west and the

Madeira River The Madeira River ( ) is a major waterway in South America. It is estimated to be in length, while the Madeira-Mamoré is estimated near or in length depending on the measuring party and their methods. The Madeira is the biggest tributary of ...

to the east, both tributaries of the

(upper Amazon). In the south it is crossed by the Igapó-Açu River, Ipixuna River, Itaparaná River, Mucuim River, and

Jari River The Jari River, or Jary River (), is a northern tributary of the Amazon River on the border between the states of Pará and Amapá in northeastern Brazil. It is in the most downstream regions of the Amazon Basin and borders the Guiana Highlands ...

. The large rivers that separate the ecoregion from surrounding regions prevent many species from migrating from or to other regions, making a distinctive environment with various endemic species. The Purus-Madeira moist forests are bounded by the Purus várzea ecoregion along the Purus and the

Monte Alegre várzea The Monte Alegre várzea (NT0141) is an ecoregion of seasonally flooded várzea forest along the Amazon River in the Amazon biome. Location The várzea forests of this ecoregion extend along the low, seasonally flooded rivers of the central and ...

along the Solimões and Madeira. The Madeira-Tapajós moist forests lie on the east shore of the Madeira. To the south there are stretches of

Iquitos várzea The Iquitos várzea (NT0128) is an ecoregion of flooded forest along rivers in Brazil, Peru and Bolivia in the west of the Amazon biome. The forest is seasonally flooded up to by whitewater rivers carrying nutrient-rich sediment from the Andes. T ...

in the

Southwest Amazon moist forests The Southwest Amazon moist forests (NT0166) is an ecoregion located in the Upper Amazon basin. The forest is characterized by a relatively flat landscape with alluvial plains dissected by undulating hills or high terraces. The biota of the sou ...

Physical

The ecoregion covers an almost entirely flat area of in the lower Amazon basin. The plain holds large meandering rivers that have formed many

oxbow lake An oxbow lake is a U-shaped lake or stream pool, pool that forms when a wide meander of a river is meander cutoff, cut off, creating a free-standing body of water. The word "oxbow" can also refer to a U-shaped bend in a river or stream, whether ...

s, and a great many small streams, all subject to annual flooding. Elevations range from . It is within the low Amazon Basin, an area of soft sediments that emerged from five to two million years ago. Soils are acidic and low in nutrients, mostly sandy

podzol Podzols, also known as podosols, spodosols, or espodossolos, are the typical soils of coniferous or boreal forests and also the typical soils of eucalypt forests and heathlands in southern Australia. In Western Europe, podzols develop on heathlan ...

s or hydromorphic

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

soils.

Ecology

The ecoregion is in the

Neotropical realm The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropics, tropical Ecoregion#Terrestrial, terrestrial ecoregions of the Americas and the entire South American temperat ...

and the

tropical and subtropical moist broadleaf forests Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature (WWF). Description TSMF is generally found in la ...

biome.

Climate

The

Köppen climate classification The Köppen climate classification divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

is "Am": equatorial, monsoonal. Average temperatures range from with a mean of . Temperatures are fairly constant throughout the year. Average annual precipitation is . Precipitation is lowest in July with an average of and highest in March with an average of .

Flora

Most of the vegetation is seasonally flooded tropical lowland rainforest. The flora have high

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

and

. In the north the forest is dense with a canopy of and emergent trees of up to . There is a dense understory. In the south the canopy is more open and the understory less dense. In the extreme south the moist forest meets patches of wooded savanna. As with other forests of the Amazon basin the main families are

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

Sapotaceae 240px, '' Madhuca longifolia'' var. ''latifolia'' in Narsapur, Medak district, India The Sapotaceae are a family of flowering plants belonging to the order (biology)">order Ericales">family (biology)">family of flowering plants belonging to th ...

Lecythidaceae The Lecythidaceae ( ) comprise a family of about 20 genera and 250–300 species of woody plants native to tropical South America, Africa (including Madagascar), Asia and Australia. Well known members of the family include the cannonball tree ...

Moraceae Moraceae is a family of flowering plants comprising about 48 genera and over 1100 species, and is commonly known as the mulberry or fig family. Most are widespread in tropical and subtropical regions, less so in temperate climates; however, their ...

Chrysobalanaceae Chrysobalanaceae is a family of flowering plants, consisting of trees and shrubs in 27 genera and about 700 species of pantropical distribution with a centre of diversity in the Amazon. Some of the species contain silica in their bodies for rig ...

Lauraceae Lauraceae, or the laurels, is a plant Family (biology), family that includes the bay laurel, true laurel and its closest relatives. This family comprises about 2850 known species in about 45 genus (biology), genera worldwide. They are dicotyled ...

and

Myristicaceae The Myristicaceae are a family of flowering plants native to Africa, Asia, Pacific islands, and the Americas and has been recognized by most taxonomists. It is sometimes called the "nutmeg family", after its most famous member, '' Myristica fragr ...

. The most common species are '' Eschweilera alba'', '' Eschweilera odora'', '' Pouteria guianensis'', '' Vantanea guianensis'', ''

Ragala sanguinolenta Ragala is a small town in Central Province, Sri Lanka. It is part of Walapane Pradeshiya Sabha, in the Nuwara Eliya District. Agriculture The town's agricultural exports consist of tea leaves to tea production companies such as Dilmah. Raga ...

'', ''

Licania apetala ''Licania'' is a genus of over 100 species of trees and shrubs in the family Chrysobalanaceae. Species are found naturally occurring in neotropical forests from southern Mexico to Brazil and the Lesser Antilles. Due to increased deforestation and ...

'' and '' Iryanthera ulei''. Four common species of palm are ''

Astrocaryum vulgare ''Astrocaryum vulgare'' is a very spiny palm native to the Guianas and the Amazon. It is a species which has greatly benefited from deforestation, as it cannot grow in undisturbed rainforest. It is common in the Pará state of Brazil, to the east ...

'', '' Oenocarpus bataua'', ''

Attalea maripa ''Attalea maripa'', commonly called maripa palm is a palm native to tropical South America and Trinidad and Tobago. It grows up tall and can have leaves or fronds long. This plant has a yellow edible fruit which is oblong ovoid and cream. An ...

'', and ''

Socratea exorrhiza ''Socratea exorrhiza'', the walking palm or cashapona, is a palm native to rainforests in tropical Central and South America. It can grow to 25 metres in height, with a stem diameter of up to 16 cm, but is more typically 15–20 m tall ...

''. The palm-like '' Spathelia excelsa'' fruits once and then dies. '' Couma utilis'' provides edible fruit. The '' Physocalymma scaberrim'' is a typical emergent with red hardwood timber used in furniture.

Fauna

There is diverse fauna with many endemic species. 165 species of mammals have been recorded, of which over 80 are bats. Primates include the

bare-eared squirrel monkey The bare-eared squirrel monkey (''Saimiri ustus'') is a squirrel monkey endemic to Brazil and possibly eastern Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The cou ...

(''Saimiri ustus''),

white-fronted capuchin White-fronted capuchin can refer to any of a number of species of gracile capuchin monkey which used to be considered as the single species ''Cebus albifrons''. White-fronted capuchins are found in seven different countries in South America: Bol ...

(''Cebus albifrons''), brown woolly monkey (''Lagothrix lagotricha''), and five species of

titi The titis, or titi monkeys, are New World monkeys of the subfamily Callicebinae, which contains three extant genera: ''Cheracebus'', ''Callicebus'', and ''Plecturocebus.'' This subfamily also contains the extinct genera '' Miocallicebus, Homuncu ...

monkey (Callicebus genus), of which Hershkovitz's titi (''Callicebus dubius''),

ashy black titi The ashy black titi monkey (''Plecturocebus cinerascens'') is a species of titi monkey, a type of New World monkey, endemic to Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the w ...

(''Callicebus cinerascens''), and

collared titi The collared titi monkey (''Cheracebus torquatus'') is a species of titi, a type of New World monkey. It is endemic to northern Brazil. Taxonomy At the end of the 1980s, the genus ''Callicebus'' was revised from the Hershkovitz concept of thre ...

(''Callicebus torquatus'') are endemic. Other mammals include

Hoffmann's two-toed sloth The Hoffmann's two-toed sloth (''Choloepus hoffmanni''), also known as the northern two-toed sloth, is a species of sloth from Central and South America. It is a solitary, largely nocturnal and arboreal animal, found in mature and secondary ra ...

(''Choloepus hoffmanni''),

brown-throated sloth The brown-throated sloth (''Bradypus variegatus'') is a species of three-toed sloth found in the Neotropical realm of Central and South America. It is the most common of the four species of three-toed sloth, and is found in the forests of Sout ...

(''Bradypus variegatus''),

silky anteater The silky anteater, also known as the pygmy anteater, has traditionally been considered a single species of anteater, ''Cyclopes didactylus'', in the genus ''Cyclopes'', the only living genus in the family Cyclopedidae. Found in southern Mexico ...

(''Cyclopes didactylus''),

southern tamandua The southern tamandua (''Tamandua tetradactyla''), also called the collared anteater or lesser anteater, is a species of anteater from South America and the island of Trinidad in the Caribbean. It is a solitary animal found in many habitats, from ...

(''Tamandua tetradactyla''),

giant anteater The giant anteater (''Myrmecophaga tridactyla'') is an Insectivore, insectivorous mammal native to Central America, Central and South America. It is the largest of the four living species of anteaters, which are classified with sloths in the or ...

(''Myrmecophaga tridactyla''),

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''),

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''),

cougar The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...

(''Puma concolor''),

red brocket The red brocket (''Mazama americana'') is a species of brocket deer from forests in South America, ranging from northern Argentina to Colombia and the Guianas. It also occurs on the Caribbean island of Trinidad (it also occurred on the island of ...

(''Mazama americana''),

gray brocket The gray brocket (''Mazama gouazoubira''), also known as the brown brocket, is a species of brocket deer from northern Argentina, Bolivia, southern Peru, eastern and southern Brazil, Paraguay, and Uruguay. It formerly included the Amazonian bro ...

(''Mazama gouazoubira''), and

South American tapir The South American tapir (''Tapirus terrestris''), also commonly called the Brazilian tapir (from the Tupi ), the Amazonian tapir, the maned tapir, the lowland tapir, (Brazilian Portuguese), and ''la sachavaca'' (literally "bushcow", in mixed ...

(''Tapirus terrestris''). Endangered mammals include

Peruvian spider monkey The Peruvian spider monkey (''Ateles chamek''), also known as the black-faced black spider monkey, is a species of spider monkey that lives in Peru, as well as in Brazil and in Bolivia. At long, they are relatively large among species of monkey, ...

(''Ateles chamek''),

white-cheeked spider monkey The white-cheeked spider monkey (''Ateles marginatus'') is a species of spider monkey, a type of New World monkey, Endemism, endemic to Brazil. It moves around the forest canopy in small family groups of two to four, part of larger groups of a fe ...

(''Ateles marginatus'') 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'').

Green iguana The green iguana (''Iguana iguana''), also known as the American iguana or the common green iguana, is a large, arboreal, mostly Herbivory, herbivorous species of lizard of the genus ''Iguana''. Usually, this animal is simply called the iguana. ...

(''Iguana iguana'') and tegus lizards (genus ''

Tupinambis ''Tupinambis'' is a lizard genus which belongs to the Family (biology), family Teiidae and contains eight described species. These large lizards are commonly referred to as tegus (''teiús'' in Portuguese language, Portuguese). ''Tupinambis meria ...

'') are common. Snakes include fer-de-lance (''

Bothrops asper The terciopelo (''Bothrops asper'') is a species of pit vipers, found from north-east Mexico to northern South America. At low to moderate elevations, its habitat ranges from northeastern Mexico to Colombian and Ecuadorian Andes, as well as Venez ...

''), palm pit-vipers (genus ''

Bothriechis ''Bothriechis'' is a genus of pit vipers, commonly called palm vipersJohn M. Mehrtens, Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . or palm-pit vipersCampbell JA, species:William W. Lamar, ...

''), coral snakes (genus ''

Micrurus ''Micrurus'' is a genus of venomous coral snakes of the family Elapidae. Geographic range Species in the genus ''Micrurus'' are endemic to the Americas. Species The following 82 species are recognized as being valid. *'' Micrurus albicinctus' ...

''), bushmasters (''

Lachesis muta ''Lachesis muta'', also known as the Southern American bushmaster or Atlantic bushmaster, is a pit viper species found in South America, as well as the island of Trinidad in the Caribbean. Two subspecies are currently recognized, including the no ...

'') and boa constrictors (''

Boa constrictor The boa constrictor (scientific name also ''Boa constrictor''), also known as the common boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the Family (b ...

''). 572 species of birds have been recorded including migrant toucan (genus ''

Ramphastos The ''Ramphastos'' genus, also known as toucans, is a genus of brightly colored, tropical birds that are found throughout Central and South America from Southern Mexico to the southern cone of the South American continent. Toucans are typically c ...

''),

Amazon parrot Amazon parrots are parrots in the genus ''Amazona''. They are medium-sized, short-tailed parrots native to the Americas, with their range extending from South America to Mexico and the Caribbean. ''Amazona'' is one of the 92 genera of parrots t ...

(genus ''

Amazona Amazon parrots are parrots in the genus ''Amazona''. They are medium-sized, short-tailed parrots native to the Americas, with their range extending from South America to Mexico and the Caribbean. ''Amazona'' is one of the 92 genera of parrots t ...

''), and macaw (genus ''

Ara Ara may refer to: Biology * ''Ara'' (bird), a genus of parrots * Ara (fish) (''Niphon spinosus''), a species of fish * L-arabinose operon, also known as ara Places * Ara (mountain), a mountain in Armenia * Ara, Armenia, a village in Armenia ...

''). Resident birds included tanagers (genera '' Tangara'' and ''

Tachyphonus ''Tachyphonus'' is a genus of birds in the tanager family Thraupidae. The genus was introduced by the French ornithologist Louis Pierre Vieillot in 1816 with the white-lined tanager as the type species. The name combines the Ancient Greek words ...

''), woodcreepers (genus ''

Xiphorhynchus ''Xiphorhynchus'' is a genus of birds in the woodcreeper subfamily (Dendrocolaptinae) that are found in Middle and South America. Taxonomy The genus ''Xiphorhynchus'' was introduced in 1827 by the English naturalist William Swainson. The name c ...

''),

resplendent quetzal The resplendent quetzal (''Pharomachrus mocinno'') is a small bird found in Central America and southern Mexico that lives in tropical forests, particularly montane cloud forests. They are part of the family Trogonidae and have two recognized s ...

(''Pharomachrus mocinno''), 15 species of curassows (genera ''

Crax ''Crax'' is a genus of curassows in the order Galliformes, a clade of large, heavy-bodied, ground-feeding birds. They are known from tropical South America with one species, the great curassow, ranging northwards through Central America as far a ...

'', '' Nothocrax'', '' Mitu'' and ''

Pauxi The genus ''Pauxi'' consists of the three species of helmeted curassows, terrestrial black fowl with ornamental casque on their heads. All are found in South America. This genus contains 3 species As indicated by analysis of mtDNA, mt and nDNA ...

''), and tinamous (genera ''

Crypturellus ''Crypturellus'' is a genus of tinamous containing mostly forest species. However, there are the odd few that are grassland or steppe tinamous. The genus contains 21 species. Taxonomy The genus ''Crypturellus'' was introduced in 1914 by the Brit ...

'' and ''

Tinamus ''Tinamus'' is a genus of birds in the tinamou family Tinamidae. This genus comprises some of the larger members of this South American family. Taxonomy The genus ''Tinamus'' was introduced in 1783 by the French naturalist Johann Hermann. The ...

''). Endangered birds include

wattled curassow The wattled curassow (''Crax globulosa'') is a threatened member of the family (biology), family Cracidae, the curassows, guan (bird), guans, and chachalacas. It is found in remote rainforests in the western Amazon basin in South America. Males h ...

(''Crax globulosa'') and

red-necked aracari The red-necked aracari or red-necked araçari (''Pteroglossus bitorquatus'') is a near-passerine bird in the toucan family Ramphastidae. It is found in Bolivia and Brazil. Taxonomy and systematics The International Ornithological Committee (I ...

(''Pteroglossus bitorquatus'').

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". Most of the environment is undamaged, apart from the south. A paved road (

) was built along the length of the region from

Humaitá Humaitá is a List of cities and towns in Paraguay, town and Districts of Paraguay, district on the Paraguay River in southern Paraguay. During the Paraguayan War, it served as the main Paraguayan stronghold from 1866 until its fall in August 186 ...

Manaus Manaus () is the List of capitals of subdivisions of Brazil, capital and largest city of the States of Brazil, Brazilian state of Amazonas (Brazilian state), Amazonas. It is the List of largest cities in Brazil, seventh-largest city in Brazil, w ...

, but it proved impossible to maintain and was closed. The

Trans-Amazonian Highway The Trans-Amazonian Highway (official designation BR-230, official name Rodovia Transamazônica ) was introduced on September 27, 1972. It is 4,000 km long, making it the third longest highway in Brazil. It runs through the Amazon forest and ...

crosses the southwestern end of the region from

Lábrea Lábrea () is the southernmost municipality in the Brazilian state of Amazonas. Economy The population of the Lábrea municipality was 46,882 as of 2020. Its area is . This makes it the sixth largest municipality in Amazonas by area and the ...

and has caused deforestation to create pasturage and agricultural fields. The southern area is threatened by controlled and uncontrolled fires. Mining in the upper sections of the Purus and Madeira rivers causes pollution and

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

. During the period from 2004 to 2011 the ecoregion experienced an annual rate of habitat loss of 0.32%. Global warming will force tropical species to migrate uphill to find areas with suitable temperature and rainfall. Low, flat ecoregions such as the Purus-Madeira moist forests are extremely vulnerable.

Notes

Sources

* * * * * {{DEFAULTSORT:Purus-Madeira moist forests Ecoregions of Brazil Amazon biome Neotropical tropical and subtropical moist broadleaf forests