The Monte Alegre várzea (NT0141) 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 ...

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 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 ...

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 ( ) 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 ...

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 a ...

, tributaries of these rivers and an isolated patch of várzea along the Mamoré River between Bolivia and Brazil. Major population centers in or near the ecoregion are

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 ...

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. Itacoatiara ...

, Coari 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 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 m ...

is downstream along the Amazon.

Physical

Elevations range from in the east, where the

Tapajós The 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. Prior to a drastic increase in illegal gold mi ...

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

Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

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 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 ...

levee A levee ( or ), dike (American English), dyke (British English; see American and British English spelling differences#Miscellaneous spelling differences, spelling differences), embankment, floodbank, or stop bank is an elevated ridge, natural ...

s, meander swales and bars. 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 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 "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 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.

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'' is a genus of flowering plants in the monotypic family Heliconiaceae. Most of the 194 known species are native to the tropical Americas, but a few are indigenous to certain islands of the western Pacific and Maluku (province), ...

'' 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 ...

and

Marantaceae The Marantaceae are a family, the arrowroot family, or the prayer plant 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). “Diversif ...

. Tree species that grow only in wetlands include '' Virola surinamensis'', '' 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 th ...

(''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), ''morete or acho'' (Ecuador), ''palma real'' (Bolivia), or ''aguaje'' (Peru), is a Arecaceae, palm t ...

'' 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''). 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 species, with tall grasses along the river margin such as ''

Gynerium sagittatum ''Gynerium'' is a monotypic genus of Neotropical plants in the grass family, native to Mexico and Colombia, Central America, South America, and the West Indies. It is classified in its own tribe Gynerieae. The sole species in the genus is ''Gy ...

'', ''

Paspalum repens ''Paspalum repens'', known as horsetail paspalum or water paspalum, is a species of grass native to South America, Central America, and North America. It is often called ''Paspalum fluitans'', though this name is treated as a synonym of ''P. repe ...

'' 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'' 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 (biology), order Malvales and the family (biology), family Malvaceae (previously emplaced in the family Bombacaceae), native to Mexico, Central America and the Caribbean, northern South America, ...

'', ''

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 lowland tropical rainforests of Central and South America, from Costa Rica, ...

'', '' Hura crepitans'', '' Pirahnea trifoliata'', '' Virola surinamensis'', ''

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 ''Hevea brasiliensis'', the Pará rubber tree, ''sharinga'' tree, seringueira, or most commonly, rubber tree or rubber plant, is a flowering plant belonging to the spurge family, Euphorbiaceae, originally native to the Amazon basin, but is now p ...

'', ''

Lecointea amazonica ''Lecointea'' is a genus of flowering plants in the family Fabaceae. It contains seven species native to the tropical Americas. * ''Lecointea amazonica'' Ducke * ''Lecointea guianensis'' * ''Lecointea hatschbachii'' * ''Lecointea lasiogyne'' * ...

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

Fauna

The ecoregion is home to 200 species of mammals including

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''),

ocelot The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...

(''Leopardus pardalis''),

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''),

capybara The capybara or greater capybara (''Hydrochoerus hydrochaeris'') is the largest living rodent, native to South America. It is a member of the genus '' Hydrochoerus''. The only other extant member is the lesser capybara (''Hydrochoerus isthmi ...

(''Hydrochoerus hydrochaeris''), kinkajou (''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 ...

(''Tayassu pecari''). The hairy-tailed bolo mouse (''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 Endemism, endemic to South America and is classified in the family Iniidae. Three subspecies are currently recogni ...

(''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 ''tuchuc ...

(''Sotalia fluviatilis'') and the endangered

Amazonian manatee The Amazonian manatee (''Trichechus inunguis'') is a species of manatee that lives in the Amazon Basin in Brazil, Peru, Colombia and Ecuador. It has thin, wrinkled brownish or gray colored skin, with fine hairs scattered over its body and a white ...

(''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 mustel ...

(''Pteronura brasiliensis'') is also endangered. Large reptiles include

black caiman The black caiman (''Melanosuchus niger'') is a crocodilian reptile endemic to South America. With a maximum length of around and a mass of over , it is the largest living species of the family Alligatoridae, and the third-largest crocodilian in ...

(''Melanosuchus niger''),

spectacled caiman The spectacled caiman (''Caiman crocodilus''), also known as the white caiman, common caiman, and speckled caiman, is a crocodilian in the family Alligatoridae. It is brownish-, greenish-, or yellowish-gray colored and has a spectacle-like ridge ...

(''Caiman crocodilus'') and

green anaconda The green anaconda (''Eunectes murinus''), also known as the giant anaconda, emerald anaconda, common anaconda, common water boa, or southern green anaconda, is a semi-aquatic boa species found in South America and the Caribbean island of Trin ...

(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 g ...

(subfamily

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

), Venezuelan red howler (''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. The term common squirrel monkey had been used as the common name for ''Saimiri sciureus'' before gene ...

(''Saimiri sciureus''), bare-eared squirrel monkey (''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 Am ...

(''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, officially the Federative Republic of Brazil, is the largest country in South America. It is the w ...

(''Callicebus cinerascens''), Hershkovitz's titi (''Callicebus dubius''), Santarem marmoset (''Mico humeralifer'') and white-footed saki (''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, Ecua ...

(''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 (''Ateles marginatus''), white-nosed saki (''Chiropotes albinasus''), black bearded saki (''Chiropotes satanas'') and

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

(''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 starte ...

'' 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 genus, ...

s (subfamily Dendrocygninae), sharp-tailed ibis (''Cercibis oxycerca)'', ibis (genus '' Theristicus''), and the

roseate spoonbill The roseate spoonbill (''Platalea ajaja'') is a social wading bird of the ibis and spoonbill family, Threskiornithidae. It is a resident breeder in both South and North America. The roseate spoonbill's pink color is diet-derived, consisting of ...

(''Platalea ajaja''). Endemic birds include ash-throated crake (''Mustelirallus albicollis''), plain-breasted ground dove (''Columbina minuta''), red-shouldered macaw (''Diopsittaca nobilis''), green-rumped parrotlet (''Forpus passerinus''), scaled ground cuckoo (''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 t ...

(''Asio stygius''). Endangered birds include sun parakeet (''Aratinga solstitialis''), wattled curassow (''Crax globulosa''),

varzea piculet The varzea piculet (''Picumnus varzeae'') is a Near-threatened species, Near Threatened species of bird in subfamily Picumninae of the woodpecker family Picidae. It is Endemism, endemic to Brazil's Amazon basin. Taxonomy and systematics The v ...

(''Picumnus varzeae''), and red-necked aracari (''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 ...

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