The Monte Alegre várzea (NT0141) is an

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

of 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 the Amazon River in the Amazon biome.

Location

The

s of this ecoregion extend along the low, seasonally flooded rivers of the central and lower basin of the Amazon River, including a large part of the

Madeira River The Madeira River ( pt, Rio Madeira, link=no ) 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 ...

basin, the mouth of 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 and ...

, tributaries of these rivers and an isolated patch of várzea along the

Mamoré River The Mamoré is a large river in Brazil and Bolivia which unites with the Beni to form the Madeira, one of the largest tributaries of the Amazon. It rises on the northern slope of the Sierra de Cochabamba, east of the city of Cochabamba, and is k ...

between Bolivia and Brazil. Major population centers in or near the ecoregion are Manaus,

Itacoatiara Itacoatiara is one of the 48 official neighborhoods into which the city of Niterói, Rio de Janeiro in Brazil is divided. Beach Itacoatiara beach is located about 30 minutes east of downtown Niterói by car, or one hour by bus. Itacoatiar ...

Coari Coari (''Choary'') is a Brazilian municipality in the Amazon region. Location The municipal seat of Coari is one of the largest cities of the Amazonas state. It is the seat of the Roman Catholic Diocese of Coari. The area has reserves of oil a ...

and Óbidos. The ecoregion adjoins the Madeira-Tapajós moist forests to the southeast and the Uatuma-Trombetas moist forests and Japurá-Solimões-Negro moist forests to the north. The Purus-Madeira moist forests lie to the west of the Madeira and the south of the Amazon. The

Purus várzea The Purus várzea (NT0156) is an ecoregion of seasonally flooded várzea forest in the central Amazon basin. It is part of the Amazon biome. The ecoregion is home to a vegetation adapted to floods of up to that may last for eight months. There ...

is upstream along the Solimões and Purus rivers and their tributaries. The

Gurupa várzea The Gurupa várzea (NT0126) is an ecoregion of seasonally and tidally flooded várzea forest along the Amazon River in the Amazon biome. Location The Gurupa várzea ecoregion is named after the Ilha Grande de Gurupá, an alluvial island in the ...

is downstream along the Amazon.

Physical

Elevations range from in the east, where the

Tapajós The Tapajós ( pt, Rio Tapajós ) is a river in Brazil. It runs through the Amazon Rainforest and is a major tributary of the Amazon River. When combined with the Juruena River, the Tapajós is approximately long. It is one of the largest clearw ...

meets the Amazon river, to on the Madeira. The soils are fertile sediments formed in the present

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

epoch, carried down from the Andes. The annual floods renew the sediments, making very rich soils compared to the higher terra firme on either side of the várzea. The river waters, loaded with sediment, rise by each year, flooding the land for as long as eight months. The river course through the floodplain constantly shifts over time, creating oxbow lakes, levees, meander swales and

bar Bar or BAR may refer to: Food and drink * Bar (establishment), selling alcoholic beverages * Candy bar * Chocolate bar Science and technology * Bar (river morphology), a deposit of sediment * Bar (tropical cyclone), a layer of cloud * Bar (u ...

s. These landscape elements support diverse vegetation, predominantly seasonally flooded tropical evergreen rainforest. Typically the levees are relatively high, formed by the deposit of sediments along the river margins. Behind them the land slopes down, flattens out and then rises to the terra firme forest. The area behind the levees holds ''canarana'' grassland and lakes that expand and contract with the flood cycle.

Climate

The

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

is "Af": equatorial, fully humid. Average monthly temperatures range from with an annual average of . Average annual rainfall in the east is less than , while in some parts of the Madeira in the west it exceeds .

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 tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeo ...

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. Description TSMF is generally found in large, discon ...

biome.

Flora

The main vegetation types are aquatic vegetation, permanent swamp vegetation, succession vegetation and forest mosaics. Typically there are fewer tree species in the várzea than on terra firme, although many trees are common to both environments. Trees in the várzea are usually shorter than on terra firme, with a canopy of up to . There are some palms, and often a dense understory of plants in the genus ''

Heliconia ''Heliconia'', derived from the Greek word (), is a genus of flowering plants in the monotypic family Heliconiaceae. Most of the ca 194 known species are native to the tropical Americas, but a few are indigenous to certain islands of the we ...

'' and families

Zingiberaceae Zingiberaceae () or the ginger family is a family of flowering plants made up of about 50 genera with a total of about 1600 known species of aromatic perennial herbs with creeping horizontal or tuberous rhizomes distributed throughout tropical Af ...

and

Marantaceae The Marantaceae are a family, the arrowroot family, of flowering plants consisting of 31 genera and around 530 species, defining it as one of the most species-rich families in its order.Kennedy, H. (2000). “Diversification in pollination mechan ...

. Tree species that grow only in wetlands include ''

Virola surinamensis ''Virola surinamensis'', known commonly as baboonwood, ucuuba, ucuhuba and ''chalviande'',Americas Regional Workshop (Conservation & Sustainable Management of Trees, Costa Rica, November 1996). 1998''Virola surinamensis''.The IUCN Red List of Thr ...

'', '' Calycophyllum spruceanum'' and

Açaí palm The açaí palm (, , from Nheengatu ''asai''), '' Euterpe oleracea,'' is a species of palm tree (Arecaceae) cultivated for its fruit (açaí berries, or simply açaí), hearts of palm (a vegetable), leaves, and trunk wood. Global demand for t ...

(''Euterpe oleracea''). The economically valuable palms '' Astrocaryum jauari'' and ''

Mauritia flexuosa ''Mauritia flexuosa'', known as the moriche palm, ''ité'' palm, ''ita'', ''buriti'', ''muriti'', ''miriti'' (Brazil), ''canangucho'' (Colombia), ''acho'' (Ecuador), or ''aguaje'' (Peru), is a palm tree. It grows in and near swamps and other wet ...

'' are common on the floodplain. Other trees that feed the fruit-eating fish that enter the forest during flood periods are the yellow mombim (''

Spondias ''Spondias'' is a genus of flowering plants in the cashew family, Anacardiaceae. The genus consists of 17 described species, 7 of which are native to the Neotropics and about 10 are native to tropical Asia. They are commonly named hog plums, Sp ...

mombim''), socoró ('' Mouriri ulei'') and tarumã (''

Vitex cymosa ''Vitex cymosa'' is a species of tree in the family Lamiaceae. It is native to Panama and South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small por ...

''). Grasses in the ''canarana'' areas include

Echinochloa ''Echinochloa'' is a very widespread genus of plants in the grass family and tribe Paniceae. Some of the species are known by the common names barnyard grass or cockspur grass. Some of the species within this genus are millets that are grown ...

and

Hymenachne ''Hymenachne'' is a genus of widespread wetlands plants that is in the grass family. They may be known commonly as marsh grasses. They are distributed in tropical and subtropical regions of Asia, the Americas, and the Pacific Islands.Clarkson, J. ...

species, with tall grasses along the river margin such as '' Gynerium sagittatum'', '' Paspalum repens'' and '' Echinocloa polystachya''. Shrubs include '' Coccoloba ovata'', '' Eugenia inundata'', '' Ruprechtia ternifolia'' and '' Symmeria paniculata''. Slightly higher up there are early succession trees such as '' Acosmium nitens'', '' Buchenavia macrophylla'', '' Cecropia latiloba'', '' Crateva benthamii'', '' Ficus anthelminthica'', '' Machaerium leiophyllum'', '' Macrolobium angustifolium'', '' Piranhea trifoliata'', ''

Pseudobombax munguba ''Pseudobombax'' is a genus of flowering plants in the subfamily Bombacoideae of the family Malvaceae Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of econ ...

'' and '' Tabebuia barbata''. Higher up again, but still in flooded areas, trees include '' Calycophyllum spruceanum'', ''

Ceiba pentandra ''Ceiba pentandra'' is a tropical tree of the order Malvales and the family Malvaceae (previously emplaced in the family Bombacaceae), native to Mexico, Central America and the Caribbean, northern South America, and (as the variety ''C. pentandr ...

'', ''

Couroupita guianensis ''Couroupita guianensis'', known by a variety of common names including cannonball tree, is a deciduous tree in the flowering plant family Lecythidaceae. It is native to the tropical forests of Central and South America, and it is cultivated in m ...

'', ''

Hura crepitans ''Hura crepitans'', the sandbox tree, also known as possumwood and jabillo, is an evergreen tree of the spurge family (Euphorbiaceae), native to tropical regions of North and South America including the Amazon rainforest. It is also present in p ...

'', '' Pirahnea trifoliata'', ''

'', ''

Genipa americana ''Genipa americana'' () is a species of trees in the family Rubiaceae. It is native to the tropical forests of North and South America, as well as the Caribbean. Description ''Genipa americana'' trees are up to 30 m tall and up to 60 cm d ...

'', '' Hevea brasiliensis'', ''

Lecointea amazonica ''Lecointea'' is a genus of flowering plants in the family Fabaceae. It contains the following species: * '' Lecointea amazonica'' Ducke * '' Lecointea ovalifolia'' J.F. Macbr. * '' Lecointea peruviana'' J.F. Macbr. * '' Lecointea tango'' (Standl ...

'', '' Sterculia elata'' and '' Rheedia brasiliensis''.

Fauna

The ecoregion is home to 200 species of mammals including jaguar (''Panthera onca''), ocelot (''Leopardus pardalis''),

South American tapir The South American tapir (''Tapirus terrestris''), also commonly called the Brazilian tapir (from the Tupi ''tapi'ira''), the Amazonian tapir, the maned tapir, the lowland tapir, the ''anta'' (Portuguese), and ''la sachavaca'' (literally "bushco ...

(''Tapirus terrestris''), capybara (''Hydrochoerus hydrochaeris''),

kinkajou The kinkajou ( /ˈkɪŋkədʒuː/ ''KING-kə-joo''; ''Potos flavus'') is a tropical rainforest mammal of the family Procyonidae related to olingos, coatis, raccoons, and the ringtail and cacomistle. It is the only member of the genus ''Potos'' ...

(''Potos flavus'') and

white-lipped peccary The white-lipped peccary (''Tayassu pecari'') is a species of peccary found in Central and South America and the only member of the genus ''Tayassu''. Multiple subspecies have been identified. White-lipped peccaries are similar in appearance to ...

(''Tayassu pecari''). The

hairy-tailed bolo mouse The hairy-tailed bolo mouse or hairy-tailed akodont (''Necromys lasiurus'') is a South American rodent species of the family Cricetidae. It is found in Argentina, Bolivia, Brazil, and Paraguay. Description The hairy-tailed bolo mouse grows to a ...

(''Necromys lasiurus''), and Amazonian sac-winged bat (''Saccopteryx gymnura'') are endemic. Aquatic mammals include

Amazon river dolphin The Amazon river dolphin (''Inia geoffrensis''), also known as the boto, bufeo or pink river dolphin, is a species of toothed whale classified in the family Iniidae. Three subspecies are currently recognized: ''I. g. geoffrensis'' (Amazon river ...

(''Inia geoffrensis''),

tucuxi The tucuxi (''Sotalia fluviatilis''), alternatively known in Peru ''bufeo gris'' or ''bufeo negro'', is a species of freshwater dolphin found in the rivers of the Amazon basin. The word ''tucuxi'' is derived from the Tupi language word ''tuchu ...

(''Sotalia fluviatilis'') and the endangered Amazonian manatee (''Trichechus inunguis'') is also endangered. The

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 muste ...

(''Pteronura brasiliensis'') is also endangered. Large reptiles include black caiman (''Melanosuchus niger''), spectacled caiman (''Caiman crocodilus'') and

green anaconda The green anaconda (''Eunectes murinus''), also known as the giant Emerald anaconda, common anaconda, common water boa or sucuri, is a boa species found in South America. It is the heaviest and one of the longest known extant snake species. Lik ...

(Eunectes murinus). Primates include

spider monkey Spider monkeys are New World monkeys belonging to the genus ''Ateles'', part of the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil. The ...

(subfamily

Atelinae The Atelinae are a subfamily of New World monkeys in the family Atelidae, and includes the various spider and woolly monkeys. The primary distinguishing feature of the atelines is their long prehensile tails, which can support their entire body w ...

Venezuelan red howler The Colombian red howler or Venezuelan red howler (''Alouatta seniculus'') is a South American species of howler monkey, a type of New World monkey, found in the western Amazon Basin in Venezuela, Colombia, Ecuador, Peru and Brazil. The populat ...

(''Alouatta seniculus''),

common squirrel monkey Common squirrel monkey is the traditional common name for several small squirrel monkey species native to the tropical areas of South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern ...

(''Saimiri sciureus''),

bare-eared squirrel monkey The bare-eared squirrel monkey (''Saimiri ustus'') is a squirrel monkey endemic to Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America ...

(''Saimiri ustus'') and

red-handed tamarin The golden-handed tamarin (''Saguinus midas''), also known as the red-handed tamarin or Midas tamarin, is a New World monkey belonging to the family Callitrichidae. Distribution and habitat This species is native to wooded areas north of the Ama ...

(''Saguinus midas''). Endemic primates include Hoffmanns's titi (''Callicebus hoffmannsi''),

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 ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest count ...

(''Callicebus cinerascens''), Hershkovitz's titi (''Callicebus dubius''),

Santarem marmoset The Santarem marmoset (''Mico humeralifer''), also known as the black and white tassel-ear marmoset, is a marmoset endemic to the Brazilian states of Amazonas and Pará. Description The Santarem marmoset is a small monkey, with a head-body leng ...

(''Mico humeralifer'') and

white-footed saki The white-footed saki, buffy saki or white saki (''Pithecia albicans'') is a species of saki monkey, a type of New World monkey, endemic to western Brazil south of the Amazon Amazon most often refers to: * Amazons, a tribe of female warriors ...

(''Pithecia albicans''). Endangered primate include

white-bellied spider monkey The white-bellied spider monkey (''Ateles belzebuth''), also known as the white-fronted or long-haired spider monkey, is an endangered species of spider monkey, a type of New World monkey. It is found in the north-western Amazon in Colombia, Ecu ...

(''Ateles belzebuth''),

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, endemic to Brazil. It moves around the forest canopy in small family groups of two to four, part of larger groups of a few dozen an ...

(''Ateles marginatus''),

white-nosed saki The white-nosed saki (''Chiropotes albinasus'') is a species of bearded saki, a type of New World monkey, endemic to the south-central Amazon rainforest in Brazil. Both its scientific and common name were caused by the authors working from dead ...

(''Chiropotes albinasus''),

black bearded saki The black bearded saki (''Chiropotes satanas'') is a species of New World monkey, native to the Amazon rainforest of South America, specifically to an area of north-eastern Brazil. It is one of five species of bearded saki. Bearded sakis are med ...

(''Chiropotes satanas'') and

pied tamarin The pied tamarin (''Saguinus bicolor''), sometimes referred to as the Brazilian bare-faced tamarin, is a Critically Endangered primate species found in a restricted area of the Brazilian Amazon Rainforest. It was named the mascot of Manaus, Bra ...

(''Saguinus bicolor''). 681 species of birds have been reported, including herons and egrets (genera ''

Egretta ''Egretta'' is a genus of medium-sized herons, mostly breeding in warmer climates. Representatives of this genus are found in most of the world, and the little egret, as well as being widespread throughout much of the Old World, has now started ...

'' and '' Ardea''),

whistling duck The whistling ducks or tree ducks are a subfamily, Dendrocygninae, of the duck, goose and swan family of birds, Anatidae. In other taxonomic schemes, they are considered a separate family, Dendrocygnidae. Some taxonomists list only one genu ...

s (subfamily Dendrocygninae),

sharp-tailed ibis The sharp-tailed ibis (''Cercibis oxycerca'') is a species of ibis native to open wet savannas in parts of northern South America. Taxonomy and systematics The sharp-tailed ibis is monotypic, being the only representative of the genus ''Cercibis ...

(''Cercibis oxycerca)'', ibis (genus ''

Theristicus ''Theristicus'' is a genus of birds in the family Threskiornithidae. They are found in open, grassy habitats in South America. All have a long, decurved dark bill, relatively short reddish legs that do not extend beyond the tail in flight (unlik ...

''), and the

roseate spoonbill The roseate spoonbill (''Platalea ajaja'') is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae. It is a resident breeder in both South and North America. Taxonomy The roseate spoonbill is sometimes placed in its own ...

(''Platalea ajaja''). Endemic birds include

ash-throated crake The ash-throated crake (''Mustelirallus albicollis'') is a species of bird in the subfamily Rallinae of the rail, crake, and coot family Rallidae.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife Internationa ...

(''Mustelirallus albicollis''),

plain-breasted ground dove The plain-breasted ground dove (''Columbina minuta'') is a species of bird in the family Columbidae. It lacks the scaled appearance to the feathers of the similar and typically more abundant common ground dove. Taxonomy In 1760 the French zoolog ...

(''Columbina minuta''),

red-shouldered macaw The red-shouldered macaw (''Diopsittaca nobilis'') is a small green South American parrot, a member of a large group of Neotropical parrots called macaws. The species is named for the red coverts on its wings. It is the smallest macaw, being i ...

(''Diopsittaca nobilis''),

green-rumped parrotlet The green-rumped parrotlet (''Forpus passerinus'') is a species of parrot in the family Psittacidae that is found in northeastern South America and the Caribbean island of Trinidad. The green-rumped parrotlet occurs from northern Venezuela eastwa ...

(''Forpus passerinus''),

scaled ground cuckoo The scaled ground cuckoo (''Neomorphus squamiger'') is a species of cuckoo in the tribe Neomorphini of subfamily Crotophaginae. It is endemic to the Amazon rainforest near the Tapajos River in Brazil. Taxonomy and systematics The scaled gro ...

(''Neomorphus squamiger''), and

stygian owl The stygian owl (''Asio stygius'') is a medium-sized "typical owl" in subfamily Striginae. It is found in Mexico, parts of Central America, Cuba, Hispaniola, and 10 countries in South America.HBW and BirdLife International (2020) ''Handbook of ...

(''Asio stygius''). Endangered birds include

sun parakeet The sun parakeet (''Aratinga solstitialis''), also known in aviculture as the sun conure, is a medium-sized, vibrantly colored parrot native to northeastern South America. The adult male and female are similar in appearance, with black beaks, pre ...

(''Aratinga solstitialis''),

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

(''Crax globulosa''), varzea piculet (''Picumnus varzeae''),

green-thighed parrot The green-thighed parrot (''Pionites leucogaster''), also known as the eastern white-bellied parrot, is a species of parrot in the family Psittacidae. The species was previously known as the white-bellied parrot (or white-bellied caique in avicul ...

(''P'ionites leucogaster'') 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 Inc. (WWF) is an 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 Wo ...

lists the ecoregion as "Critical/Endangered". The ecoregion is threatened by contamination of the water and fish by gold mining, and heavy sedimentation caused by destruction of the forests. Huge areas of the floodplain forests are cleared and burned by ranchers to create pastures for livestock. Global warming will force tropical species to migrate uphill to find areas with suitable temperature and rainfall. Low, flat, deforested ecoregions such as the Monte Alegre várzea are extremely vulnerable.

Notes

Sources

* * * * {{DEFAULTSORT:Monte Alegre varzea Ecoregions of Brazil Amazon biome Neotropical tropical and subtropical moist broadleaf forests