Orinoco Delta swamp forests
Orinoco Delta swamp forests | |
---|---|
Ecology | |
Realm | Neotropical |
Biome | Tropical and subtropical moist broadleaf forests |
Geography | |
Area | 27,972 km2 (10,800 sq mi) |
Country | Guyana, Venezuela |
Coordinates | 9°01′41″N 61°23′46″W / 9.028°N 61.396°W |
Climate type | Af: equatorial, fully humid |
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.
Location
The Orinoco Delta swamp forests in the lower delta plain of the Orinoco River are one of Earth's largest intact areas of wetlands. They cover an area of 27,972 square kilometres (10,800 sq mi).[1] The forests extend from the base of the Paria Peninsula in the northeast of Venezuela south across the Orinoco Delta floodplain to the Waini River of Guyana.[2]
The ecoregion is bounded on the
Physical
The terrain is flat, with typical elevations of 1 metre (3 ft 3 in) above sea level, but in the south there are terra firme levees up to 9 metres (30 ft) high. The soils are alluvial deposits carried by rivers from the Andes of Colombia and Venezuela. The Orinoco fans out into large and small
Climate
The Köppen climate classification is "Af": equatorial, fully humid.[4] Annual rainfall varies by location from 500 to 2,000 millimetres (20 to 79 in), and is highest in the south. A wet season generally lasts from April/May to December.[2] At a sample location at coordinates 8°45′N 61°15′W / 8.75°N 61.25°W the temperature is relatively stable throughout the year, slightly cooler in January and July and slightly warmer in May and October. Yearly average minimum temperature is 22 °C (72 °F) and maximum is 31 °C (88 °F) with a mean temperature of 27 °C (81 °F). Yearly total rainfall is about 1,450 millimetres (57 in). Average monthly rainfall varies from 40.5 millimetres (1.59 in) in February to 203.7 millimetres (8.02 in) in July.[4]
Ecology
The Orinoco Delta swamp forests are in the Tropical and subtropical moist broadleaf forests biome.[1] The ecoregion is part of the Guianan Moist Forests Global Ecoregion, which also includes the Guianan moist forests and the Paramaribo swamp forests.[5]
Flora
The Orinoco delta is largely covered by permanently flooded tropical ombrophilous swamp forest, which support various endemic species of plants, with areas of wetlands, mangroves and
Fauna
The swamp forests are home to species that include Orinoco crocodile (Crocodylus intermedius), Amazon river dolphin (Inia geoffrensis), jaguar (Panthera onca), bush dog (Speothos venaticus), giant otter (Pteronura brasiliensis), Orinoco goose (Neochen jubata) and harpy eagle (Harpia harpyja).[2] Endangered species include the Orinoco crocodile, giant otter and yellow-bellied seedeater (Sporophila nigricollis).[6]
Status
The
The highest risk now comes from oil exploration, which would bring more people into the region and cause forest clearance for food and building materials. The way of life of the indigenous Warao people would be disturbed by the newcomers. In some areas the açaí (Euterpe oleracea) and moriche (Mauritia flexuosa) palm trees are over-exploited. Although the region is largely inaccessible, there is growing concern about logging. The cleared land is poor quality and cannot support farming.[2]
There are two indigenous reserves, which do not provide much protection, and several conservation units. The 876,500 hectares (2,166,000 acres) Delta del Orinoco Biosphere Reserve is a sustainable use unit. Part of it covers wetlands. The 3,203,250 hectares (7,915,400 acres) Imataca Forest Reserve is another sustainable use unit with a portion that covers the eastern coastal wetlands.[2] National parks in Venezuela are fully protected, and cover parts of the wetlands and surrounding ecoregions. They include the 331,000 hectares (820,000 acres)
References
- ^ a b Orinoco Delta swamp forests – Meyers, WWF Abstract.
- ^ a b c d e f g h i j Schipper.
- ^ WildFinder – WWF.
- ^ a b Orinoco Delta swamp forests – Meyers, Climate Data.
- ^ Guianan Moist Forests – WWF Global.
- ^ Orinoco Delta swamp forests – Meyers, All Endangered.
Sources
- Guianan Moist Forests, WWF Global, archived from the original on 2017-06-05, retrieved 2017-05-22
- "Orinoco Delta swamp forests", Global Species, Meyers Enterprises II, retrieved 2017-04-05
- Schipper, Jan, Northern South America: Northeastern Venezuela and northwestern Guyana (NT0147), retrieved 2017-04-05
- WildFinder, WWF: World Wildlife Fund, retrieved 2017-03-25