Madeira–Tapajós moist forests
Tapajós river at Itaituba, Pará
Location in Brazil and Bolivia
Ecology
Realm	Neotropical
Biome	Tropical and subtropical moist broadleaf forests – Amazon
Geography
Area	719,757.69 km2 (277,900.00 sq mi)
Country	Brazil, Bolivia
Coordinates	8°45′50″S 61°36′18″W / 8.764°S 61.605°W / -8.764; -61.605

The Madeira–Tapajós moist forests (NT0135) is an ecoregion in the Amazon basin. It is part of the Amazon biome. The ecoregion extends southwest from the Amazon River between its large Madeira and Tapajós tributaries, and crosses the border into Bolivia. In the south it transitions into the cerrado biome of Mato Grosso. In the state of Rondônia it contains some of the most degraded land of the Amazon basin.

Location

The Madeira–Tapajós moist forests cover an area of 71,975,769 hectares (177,856,000 acres). They stretch in a southwest direction through Brazil from the Amazon into northeast Bolivia.^[1] The ecoregion covers parts of the states of Amazonas, Rondônia and Mato Grosso in Brazil, and part of the Beni Department in Bolivia.^[2]

The ecoregion covers the interfluvial region between the Madeira River to the west and the Tapajós rivers to the east, two large tributaries of the Amazon to the north. Above the sources of the Tapajós the ecoregion extends south to the Guaporé River basin. The large rivers prevent the spread of flora and fauna. Thus the white-fronted capuchin (Cebus albifrons) and hairy saki (Pithecia hirsuta) are found west of the Tapajós, while the white-nosed saki (Chiropotes albinasus) is only found east of the river. In the south the bounds of the ecoregion are defined by distinct changes in vegetation, with the transition to Mato Grosso tropical dry forests in the southeast and to the Beni savanna and later the Chiquitano dry forests in the southeast.^[2]

To the northwest the ecoregion is separated from the Purus-Madeira moist forests by the Madeira River, which has Monte Alegre várzea along much of its length. The várzea extends along the Amazon River on the north of the ecoregion. To the east it is separated by the Tapajós river from the Tapajós–Xingu moist forests ecoregion. Further south along its southeast boundary it adjoins the Mato Grosso seasonal forests, Cerrado and Chiquitano dry forests ecoregions. In the southwest it adjoins the Southwest Amazon moist forests and Beni savanna ecoregions.^[3]

Physical

Most of the ecoregion is below 200 metres (660 ft) in elevation.^[2] At its northern boundary on the Amazon river the elevation is 20 metres (66 ft) above sea level.^[1] The ecoregion south of the river covers part of the low, flat Amazon basin, and rises gradually to the south and east to uplifted parts of the old Brazilian Shield. The southern part of the ecoregion contains the mountainous Parecis plateau (Chapada dos Parecis).^[2] The land rises to 1,126 metres (3,694 ft) at the tallest peak of the Parecis plateau.^[1][a] The terrain here consists of table mountains with rocky meadows and semi-deciduous open submontane forest and woodland savanna.^[2]

The Madeira River is a sediment-rich whitewater river. The clearwater Tapajós, which rises in the ancient and well-weathered Brazilian Shield and follows a fixed course, does not carry sediment. Other large rivers in the region are the Maués Açu, Aripuanã and Canumã.^[2] The Parecis plateau's main rivers are the Ji-Paraná, Juruena, Papagaio, do Sangue and Guaporé.^{[citation needed]}

Ecology

The ecoregion is in the Neotropical realm and the tropical and subtropical moist broadleaf forests biome.^[1]

Status

The World Wildlife Fund classes the ecoregion as Vulnerable. The main threats come from deforestation and colonization along the main rivers and the highways.^[2] During the period from 2004 to 2011 the ecoregion experienced an annual rate of habitat loss of 0.61%.^[6] Part of the ecoregion in central Rondônia is one of the most degraded areas of the central Amazon basin, with the forests cut down and the land degraded. This is worst along the BR-364 highway from Cuiabá to Porto Velho and the BR-319 from there to Humaitá and also occurs along the BR-230 Trans-Amazonian Highway from Humaitá to the middle Tapajós. The banks of the Tapajós and Madeira have large areas that are scarred by large-scale illegal mining. Conservation units such as the Amazônia National Park and Pacaás Novos National Park are underfunded and poorly protected.^[2]

Notes

Sources