The Gurupa várzea (NT0126) 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 and tidally 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 Gurupa várzea ecoregion is named after the Ilha Grande de Gurupá, an alluvial island in the mouth of the Amazon. The várzea extends along the lower Amazon River from the mouth of 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 ...

down to the mouth of the

Xingu River The Xingu River ( ; ; ) is a river in north Brazil. It is a southeast tributary of the Amazon River and one of the largest clearwater rivers in the Amazon basin, accounting for about 5% of its water. __TOC__ Description and history The fir ...

. It has an area of . The Tapajós–Xingu moist forests lie to the south and the

Uatuma–Trombetas moist forests The Uatuma–Trombetas moist forests (NT0173) is an ecoregion in northwest Brazil in the Amazon biome. It covers the Amazon basin north of the Amazon River from close to the Atlantic Ocean to the Rio Negro west of Manaus. The ecoregion is relati ...

to the north. 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 ...

is upstream and the

Marajó várzea The Marajó várzea (NT0138) is an ecoregion of seasonally and tidally flooded várzea forest in the Amazon biome. It covers a region of sedimentary islands and floodplains at the mouth of the Amazon that is flooded twice daily as the ocean tides ...

is downstream along the Amazon.

Physical

In this region the

whitewater Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, froths, making t ...

Amazon is fed by the blackwater Xingú,

Jari Jari may refer to: Finnish male given name The name ''Jari'' derives from the Finnish name ''Jalmari'', which in turn derives from the Old Norse male name ''Hjalmar'' or ''Hjálmarr'' (''hjalmr'' 'helmet' + ''arr'' 'warrior/army'). With the influe ...

, and

rivers. Elevations are no more than . The Gurupa várzea contains floodplains along the river that are affected by daily Atlantic Ocean tidal fluctuations and seasonal flooding. At the height of the rainy season when the Amazon is in full flood water levels may fluctuate by in a tidal period as the river water is dammed by the rising ocean tide. Outside the rainy season fluctuations may still be from in a tidal period. The region contains a complex maze of channels and sedimentary islands. The soil is made up of sediments carried from the eastern

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

by the rivers during 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. The river sediments form levees along the margin of the river, behind which are areas of savanna on clay soil and open lakes. Both the savanna and the lakes flood daily, and the lakes grow much larger at the height of the flood season.

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, monsoon rainfall. Temperatures are fairly steady throughout the year, ranging from with an average of . Mean annual precipitation is about , with rainfall varying from in October to in April.

Flora

The levees hold tropical rainforest with a height of around . Behind them the ecoregion holds a distinctive form of várzea that is mostly savanna rather than dense rainforest. The clay soil supports robust savanna known as canarana. The rich sediments make the várzea very fertile compared to the ''terra firme'' land further from the river. The vegetation stabilizes the soil and is home to a very diverse population of aquatic mammals and freshwater fish. The flooded savanna holds large grasses such as ''

Echinochloa polystachya ''Echinochloa polystachya'', the German grass, is a species of grass (family Poaceae), native to the New World Tropics and Subtropics, from Texas and Florida down to Argentina. It is an aquatic or semi-aquatic perennial that can grow in water as ...

'', ''

Echinochloa spectabilis ''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 a ...

'', ''

Hymenachne amplexicaulis ''Hymenachne amplexicaulis'', also known as West Indian marsh grass in the US, Olive hymenachne in Australia, and hereafter referred to as hymenachne, is New World species in the genus Genus (; : genera ) is a taxonomic rank above species and ...

'', ''

Hymenachne donacifolia ''Hymenachne'', synonym ''Dallwatsonia'', is a genus of widespread wetland plants in the grass family Poaceae. They are commonly known as marsh grasses. They are distributed in tropical and subtropical regions of Asia, the Americas, and the Pacif ...

'', ''

Leersia hexandra ''Leersia hexandra'' is a species of grass known by the common names southern cutgrass, clubhead cutgrass, and swamp rice grass.

'', '' Paspalum platyaxix'', '' Luziola spruceana'', '' Panicum elephantipes'', '' Paspalum fasciculatum'' and several ''

Oryza ''Oryza'' is a genus of plants in the grass family. It includes the major food crop rice (species '' Oryza sativa'' and '' Oryza glaberrima''). Members of the genus grow as tall, wetland grasses, growing to tall; the genus includes both annua ...

'' species. Some of the grasses also grow on former channels of the river. Among the grasses there are sedges such as '' Scirpus cubensis'', '' Cyperus luzulae'', '' Cyperus ferax'' and '' Scleria geniculata''. The areas of transition between the forest and river hold shrubs and small vines that include '' Artemisia artemisiifolia'', '' Ipomoea carnea'', '' Polygonum punctatusm'', '' Justicia obtusifolia'', ''

Alternanthera philoxeroides ''Alternanthera philoxeroides'', commonly referred to as alligator weed, is a native species to the temperate regions of South America, which includes Argentina, Brazil, Paraguay and Uruguay. Argentina alone hosts around 27 species that fall with ...

'', '' Capironia fistulosa'', '' Sesbania exasperata'', ''

Mimosa pigra ''Mimosa pigra'', commonly known as the giant sensitive tree (''pigra'' = lazy, slow), is a species of plant of the genus ''Mimosa'', in the family Fabaceae. The genus ''Mimosa'' (Mimosaceae) contains 400–450 species, most of which are native ...

'', '' Montrichardia linifolia'', '' Clamatis aculeata'', '' Senna reticulata'', '' Phaseolus lineatus'', '' Rhabdadenia macrostoma'' and '' Clitonia triquetum''. The forest holds larger trees such as ''

Hura crepitans ''Hura crepitans'', the sandbox tree, also known as possumwood, monkey no-climb, assacu (from Tupi ''asaku'') and jabillo, is an evergreen tree in the family Euphorbiaceae, native to tropical regions of North and South America including the Amaz ...

'', '' Triplaris surinamensis'', '' Calycophyllum spruceanum'', '' Cedrela oderata'', '' Pseudobombax munguba'', ''

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 ...

'' and ''

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, ...

''. A variety of trees produce fleshy fruit that supports species of fruit eating primates, bats and fish that enter the forest when it is flooded. These include yellow mombim ('' Spondias mombim''), buriti palm (''

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 ...

''),

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''), socoró ('' Mouriri ulei'') and tarumã ('' Vitex cymosa'').

Fauna

This ecoregion hosts 148 mammal species including

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''),

margay The margay (''Leopardus wiedii'') is a small wild cat native to Mexico, Central and South America. A solitary and nocturnal felid, it lives mainly in primary evergreen and deciduous forest. Until the 1990s, margays were hunted for the wildl ...

(''Leopardus wiedii''),

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 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 ''Pot ...

(''Potos flavus''),

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''),

red-faced spider monkey The red-faced spider monkey (''Ateles paniscus''), also known as the Guiana spider monkey or red-faced black spider monkey, is a species of spider monkey found in the rain forests in northern South America. The species faces issues with hunting ...

(''Ateles paniscus'') and Venezuelan red howler (''Alouatta seniculus''). Endemic mammals include

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''), bare-eared squirrel monkey (''Saimiri ustus''), red-bellied titi (''Callicebus moloch''), silvery marmoset (''Mico argentatus''),

black dwarf porcupine The black dwarf porcupine, also known as Koopman's porcupine (''Coendou nycthemera''), is a porcupine species from the New World porcupine family endemic to northern Brazil. It occurs in the Amazon rainforest east of the Madeira River and south o ...

(''Coendou nycthemera''), red acouchi (''Myoprocta acouchy''),

white-faced spiny tree-rat The white-faced spiny tree-rat (''Echimys chrysurus'') is a spiny rat species from South America. It is found in Brazil, French Guiana, Guyana and Suriname. The etymology of the species name derives from the two ancient greek Ancient G ...

(''Echimys chrysurus''), giant tree rat (''Toromys grandis''),

crab-eating fox The crab-eating fox (''Cerdocyon thous''), also known as the forest dog, wood fox, bushfox (not to be confused with the bush dog) or maikong, is an extant species of medium-sized canid endemic to the central part of South America since at least ...

(''Cerdocyon thous'') and several species of bat. Endangered mammals include the

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''),

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'') 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''). 558 bird species have been recorded, 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, ...

(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 ('' Theristicus'' species),

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''),

dark-winged trumpeter The dark-winged trumpeter or green-winged trumpeter (''Psophia viridis'') is a species of bird in the family Psophiidae. It is endemic to Brazil. Taxonomy and systematics The dark-winged trumpeter's taxonomy is far from settled. The Internati ...

(''Psophia viridis''), eared dove (''Zenaida auriculata''), crimson topaz (''Topaza pella''), scaled spinetail (''Cranioleuca muelleri'') and spectacled thrush (''Turdus nudigenis''). Endangered birds include the scaled spinetail (''Cranioleuca muelleri'') and yellow-bellied seedeater (''Sporophila nigricollis'') The waters are home to many fish and turtles, including

Arrau turtle The Arrau turtle (''Podocnemis expansa''), also known as the South American river turtle, giant South American turtle, giant Amazon River turtle, Arrau sideneck turtle, Amazon River turtle or simply the Arrau, is the largest of the side-neck tu ...

(''Podocnemis expansa''). The largest fish include pacu (genera ''

Metynnis ''Metynnis'' is a genus of serrasalmid fish from tropical and subtropical South America. They are herbivorous or omnivorous, and inhabit a wide range of freshwater habitats, ranging from rivers and streams (both fast- and slow-flowing), to floodp ...

'' and ''

Mylossoma ''Mylossoma'' is a genus of serrasalmids from tropical and subtropical South America, including the basins of the Amazon, Orinoco, Lake Maracaibo and Paraguay- Paraná. These common fish are found both in main river sections and floodplains. They ...

''),

tambaqui The tambaqui (''Colossoma macropomum'') is a large species of freshwater fish in the family Serrasalmidae. It is native to tropical South America, but kept in aquaculture and Introduced species, introduced elsewhere. It is also known by the names ...

(''Colossoma macropomum''), pirarucu (''

Arapaima gigas ''Arapaima gigas'', also known simply as Arapaima, pirarucu, or paiche,Miranda-Chumacero, G., Wallace, R., Calderón, H., Calderón, G., Willink, P., Guerrero, M., ... & Chuqui, D. (2012). Distribution of arapaima (Arapaima gigas)(Pisces: Arapaim ...

'') and sardinha ('' Triportheus angulatus''). Other fish include piranha (genus ''

Serrasalmus ''Serrasalmus'' is a genus of piranhas. They are collectively known as pirambebas; the "typical" piranhas like the piraya piranha are nowadays placed in '' Pygocentrus''. Like all piranhas, ''Serrasalmus'' are native to South America. These fis ...

''), discus ('' Symphysodon aequifasciatus''),

cichlid Cichlids () are a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with on ...

s, characins (family

Anostomidae The Anostomidae are a family of ray-finned fishes that belong to the order Characiformes. Closely related to the Chilodidae and formerly included with them, the Anostomidae contain about 150 described species. Commonly known as anostomids, they ...

), tetras (genera ''

Hemigrammus ''Hemigrammus'' is a genus of freshwater fish in the family (biology), family Characidae native to South America (including Trinidad) and commonly seen in the aquarium trade. These are medium-small tetras where the largest species reach up to ar ...

'' and ''

Hyphessobrycon ''Hyphessobrycon'' is a genus of freshwater fish in the family (biology), family Characidae. These species are among the fishes known as tetras. The genus is distributed in the Neotropical realm from southern Mexico to Río de la Plata in Argenti ...

''), and catfish (families

Aspredinidae The Aspredinidae are a small South American family (biology), family of catfishes (order (biology), order Siluriformes) also known as the banjo catfishes, with about 43 species. Distribution Aspredinids are found throughout the major tropical ri ...

Callichthyidae Callichthyidae is a family of catfishes (order Siluriformes), called armored catfishes due to the two rows of bony plates (or scutes) along the lengths of their bodies. It contains some of the most popular freshwater aquarium fish, such as many ...

Doradidae The Doradidae are a family of catfishes also known as thorny catfishes, raphael catfishes or talking catfishes. These fish are native to South America, primarily the Amazon basin and the Guianas. Doradids are omnivorous. Taxonomy As of 2007, 3 ...

and

Loricariidae Loricariidae is the largest family (biology), family of catfish (order Siluriformes), with over 90 genus, genera and just over 680 species. Loricariids originate from freshwater habitats of Costa Rica, Panama, and tropical and subtropical South A ...

Status

As of 2017 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 ...

classed the ecoregion as "Critical/Endangered". Human activities in the ecoregion include fishing, subsistence agriculture, selective logging and cattle or water buffalo ranching. The small-scale farmers typically practice diverse agriculture that depends on the forest and does not degrade the land. In the past, large scale production of jute damaged the environment, and mechanized rice production continues today. Elsewhere large areas of natural forest along the Amazon banks have been cleared and the savanna converted to pasturage. Most of the commercially value timber species such as

and

have been harvested. The remaining forest is mostly secondary growth, either managed or unmanaged. Urban sprawl in the city of Monte Alegre has also affected the ecoregion.

Notes

Sources

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