Located on the northeast coast of South America, the Guianan Moist Forests ecoregion is one of the largest continuous tracts of relatively pristine lowland tropical rain forest in the world. It holds a wide variety of regional biodiversity with high levels of species endemism and richness.
The Guianan Moist Forests ecoregion is one of the largest continuous tracts of relatively pristine lowland tropical rain forest in the world. This region is located on the northeast coast of South America. The Amazon basin lies to the south and the Orinoco borders on the west.
The ecoregion covers most of Guyana, Suriname, and French Guiana. It covers part of eastern Venezuela and parts of the north of the Brazilian states of Pará and Amapá. It has a total area of 51,281,764 ha (126,720,000 acres).
The local and regional climate types in these forests are generally hot and wet, and are strongly influenced by the northeastern trade winds (vientos alisios) and the Intertropical Convergence Zone (ITCZ). The result is that moisture-rich air is constantly blown inland from the Atlantic – regulated by annual oscillations of the ITCZ. There is some variation in precipitation through the region, which can range between 2000 – 4000 mm (79 – 157 in) annually. Yearly average temperatures are minimum 21.5 °C (70.7 °F) and maximum 30.5 °C (86.9 °F) with a mean of 26 °C (79 °F).
This ecoregion encompasses a large block of lowland and submontane forest, with a wide variety of regional and local floral and faunal biodiversity, and with high levels of species endemism and richness. Since the first explorers and biologists arrived here this areas has been recognized as an important center and dispersal route for many species.
There are an estimated 8,000 vascular plant species, of which half may be endemic. The plant species in the forests change from east to west, with species dominant in one area completely missing from another. There are also patches of savanna, and the coastal lowlands have patches of herbaceous swamp. The flora is diverse. The upper tiers of the forest may reach a height of 40 m (130 ft). The trees are mainly evergreen, but may shed leaves in the dry season. The trees hold many epiphytes and parasites, and shrubs and herbaceous plants cover the forest floor.
More than 220 species of mammals have been identified in Guyana alone, of which more than 100 are bats. Endemic species include rufous mouse opossumMarmosa lepida), six-banded armadillo (Euphractus sexcinctus), red-handed tamarin (Saguinus midas) white-faced saki(Pithecia pithecia), red-faced spider monkey (Ateles paniscus), Neotropical pygmy squirrel (Sciurillus pusillus), delicate pygmy rice rat(Oligoryzomys delicatus), Guiana bristly mouse (Neacomys guianae), Bahia porcupine (Coendou insidiosus), white-faced spiny tree-rat(Echimys chrysurus), Schultz's round-eared bat (Lophostoma schulzi), and rufous dog-faced bat (Molossops neglectus). Endangered mammals include the ;black bearded saki (Chiropotes satanas) and giant otter (Pteronura brasiliensis).
There are many birds species, often the same as in the Guyana Highlands and northern Andes, such as Guianan cock-of-the-rock (Rupicola rupicola), or the Amazon lowlands, such as hoatzin (Opisthocomus hoazin). Raptors include harpy eagle (Harpia harpyja) and crested eagle(Morphnus guianensis). Endangered birds include the sun parakeet (Aratinga solstitialis) and yellow-bellied seedeater (Sporophila nigricollis).
Reptiles include the threatened black caiman (Melanosuchus niger) and yellow-spotted river turtle (Podocnemis unifilis). There are diverse amphibians in the Hylidae, Poison dart frog (Dendrobatidae) and Leptodactylidae families.