Ecology
The ecoregion is in the neotropical realm, in the tropical and subtropical moist broadleaf forests biome. The ecoregion is part of the Guianan Moist Forests Global Ecoregion, which also includes the Guianan moist forests and the Orinoco Delta swamp forests. It transitions into the Guianan moist forests ecoregion to the south, and into the Amazon-Orinoco-Southern Caribbean mangroves ecoregion along the coast.
Flora
The trees are generally shorter and less diverse than the terra firme moist forests further inland. Towards the coast they transition into mangroves. The forests contain many species of flora adapted to the swampy conditions, including several endemic species. Vegetation includes swamp forest, swamp wood, swamp scrub and herbaceous swamp.
The soils are mostly covered in a layer of peat , and peat fires often prevent vegetation from reaching the climax stage. Where fires do not occur, the greatest diversity of flora is found in the shallower swamps. In the shallower northern swamps in the climax phase characteristic trees include baboonwood ( Virola surinamensis ), chewstick ( Symphonia globulifera ) and açaí palm (Euterpe oleracea). In the deeper southern swamps there are fewer species of flora. Climax species include Crudia glaberrima , arapari ( Macrolobium acaciifolium ) and piritu ( Bactris maraja ).
Swamp woods in shallower waters often contains stands with one or two dominant tree species. These include purple coraltree ( Erythrina fusca ), dragon blood tree ( Pterocarpus officinalis ) growing with white cedar ( Tabebuia insignis ), and paradise plum ( Chrysobalanus icaco ) growing with pond apple ( Annona glabra ), buriti palm ( Mauritia flexuosa ) or mulato tree ( Triplaris surinamensis ). The northern scrub and herbaceous swamps are often dominated by a few plants such as southern cattail ( Typha domingensis ), southern cutgrass ( Leersia hexandra ) and piripiri ( Cyperus giganteus ) in the north and giant spikerush ( Eleocharis interstincta ), burr sedge ( Lagenocarpus guianensis ) and golden beaksedge ( Rhynchospora corymbosa ) in the south.
Fauna
The ecoregion has fairly diverse mammals, but no endemic species have been identified. Primates include red-handed tamarin (Saguinus midas), common squirrel monkey (Saimiri sciureus), white-faced saki (Pithecia pithecia), tufted capuchin (Sapajus apella) and Venezuelan red howler (Alouatta seniculus). Other large mammals include West Indian manatee (Trichechus manatus), giant otter (Pteronura brasiliensis) and jaguar (Panthera onca).
The coastal plain is an important breeding, wintering and passage area for waterfowl such as scarlet ibis (Eudocimus ruber) and semipalmated sandpiper (Calidris pusilla). Other birds include chestnut-bellied seed finch (Oryzoborus angolensis), ruddy-breasted seedeater (Sporophila minuta), slate-coloured seedeater (Sporophila schistacea), arrowhead piculet (Picumnus minutissimus), blood-coloured woodpecker (Veniliornis sanguineus) and crimson-hooded manakin (Pipra aureola).
Status
The World Wildlife Fund gives the ecoregion the status of "Vulnerable". The swamp forests are inhospitable, so large areas are fairly intact. However, they can be accessed via the waterways, roads and dykes for the purpose of logging and capturing primates and birds for sale as pets. Threats come from grass and peat fires, draining the swamps for farming, damming the rivers to form reservoirs for agriculture, logging and firewood collection, subsistence hunting, bauxite mining and industry. The forests are also damaged by urban sprawl, roads and canals, exotic plants and agrochemicals. Protected areas include the Galibi, Wia Wia, Peruvia, Boven Coesewijne, Copi, and Wanekreek nature reserves.
The Global 200 is the list of ecoregions identified by the World Wide Fund for Nature (WWF), the global conservation organization, as priorities for conservation. According to WWF, an ecoregion is defined as a "relatively large unit of land or water containing a characteristic set of natural communities that share a large majority of their species dynamics, and environmental conditions". For example, based on their levels of endemism, Madagascar gets multiple listings, ancient Lake Baikal gets one, and the North American Great Lakes get none.
The Orinoco Delta is a vast river delta of the Orinoco River, located in eastern Venezuela.
Campinarana, also called Rio Negro Campinarana, is a neotropical ecoregion in the Amazon biome of the north west of Brazil and the east of Colombia that contains vegetation adapted to extremely poor soil. It includes savanna, scrub and forest, and contains many endemic species of fauna and flora.
The Caquetá moist forests (NT0107) is an ecoregion of tropical moist broad leaf forest to the east of the Andes in the east of Colombia, with a small section in Brazil, in the Amazon biome. The forests are in the transition between the Guiana and Amazon regions, and have highly diverse flora and fauna. They are relatively intact, although they are mostly unprotected and are threatened with deforestation to create cattle pastures.
The Guianan savanna (NT0707) is an ecoregion in the south of Venezuela, Guyana and Suriname and the north of Brazil. It is in the Amazon biome. The savanna covers an area of rolling upland plains on the Guiana Shield between the Amazon and Orinoco basins. It includes forested areas, but these are shrinking steadily due to the effect of frequent fires, either accidental or deliberate. The ecoregion includes the Gran Sabana region of Venezuela.
The Negro–Branco moist forests (NT0143) is an ecoregion of tropical moist broadleaf forest to the east of the Andes in southern Venezuela, eastern Colombia and northern Brazil, in the Amazon biome. It lies on the watershed between the Orinoco and Rio Negro basins. It includes both blackwater and whitewater rivers, creating different types of seasonally flooded forest. The vegetation is more typical of the Guiana region than the Amazon.
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 push the river waters onto the land. The flooded forests provide food for a wide variety of fruit-eating fish, aquatic mammals, birds and other fauna. It has no protected areas and is threatened by cattle and water-buffalo ranching, logging and fruit plantations.
The Gurupa várzea (NT0126) is an ecoregion of seasonally and tidally flooded várzea forest along the Amazon River in the Amazon biome.
The Tocantins–Araguaia–Maranhão moist forests (NT0170), also called the Tocantins/Pindaré moist forests, is an ecoregion in the north of Brazil to the south of the mouth of the Amazon River. It is part of the Amazon biome. The ecoregion contains the city of Belém, capital of the state of Pará. It is the most developed part of the Amazon region, and is one of the most severely degraded natural habitats of the region.
The Solimões-Japurá moist forests (NT0163) is an ecoregion in northwest Brazil and eastern Peru and Colombia in the Amazon biome. It has a hot climate with high rainfall throughout the year, and holds one of the most diverse collections of fauna and flora in the world. The ecoregion is relatively intact.
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 relatively intact, although it has been damaged along the main rivers and around population centers.
The Guayanan Highlands moist forests (NT0124) is an ecoregion in the south of Venezuela and the north of Brazil and in Guyana, Suriname, French Guiana. It is in the Amazon biome. It encompasses an upland region with diverse fauna and flora, which contains dramatic tepuis, or sandstone table mountains. The region has been inaccessible in the past and is generally fairly intact, apart from the north and northeast where large scale agriculture, ranching and mining operations are steadily encroaching on the ecosystem. New roads are opening the interior to logging, and planned dams will have a drastic impact on the riparian zones.
The Guianan moist forests (NT0125) is an ecoregion in the east of Venezuela, north of Brazil and the Guyanas. It is in the Amazon biome. The climate is hot and humid, with two rainy seasons each year. As of 1996 the tropical rainforest habitat was relatively intact, although there were mounting threats from illegal logging and gold mining.
The Amazon–Orinoco–Southern Caribbean mangroves (NT1401) is an ecoregion along the coasts of Colombia, Venezuela, Guyana, Suriname, French Guiana and Brazil.
The Guianan mangroves (NT1411) is a coastal ecoregion of southeastern Venezuela, Guyana, Suriname, French Guiana and Brazil. The mangroves provide an important habitat for migrating birds that winter in the area. Large areas are intact, although they are threatened by destruction of the trees for timber and to make way for agriculture, and from upstream agricultural and industrial pollution.
The Orinoco Delta swamp forests (NT0147) is an ecoregion of eastern Venezuela and northern Guyana covering the large and shifting Orinoco Delta. The vegetation is mostly permanently flooded rainforest. The ecoregion is relatively intact apart from a large area that was damaged by a failed flood control program in the 1960s. It is inaccessible, so logging is difficult, and the soil is unsuitable for farming. The main threat comes from oil exploration, which would bring an influx of settlers into the delta.
The Orinoco wetlands (NT0906) is an ecoregion of northeast Venezuela within the northern Orinoco Delta. It holds areas of tall grasses in flooded land, surrounded by mangroves and swamp forest, giving way to the drier Llanos savanna in the west.
The Guayaquil flooded grasslands (NT0905) is an ecoregion near the Pacific coast of the Ecuador. The ecoregion is critically endangered due to conversion into agricultural land.
