Southwest Amazon moist forests
Encyclopedia
Ecoregion
An ecoregion , sometimes called a bioregion, is an ecologically and geographically defined area that is smaller than an ecozone and larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural...
located in the Upper Amazon Basin
Amazon Basin
The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...
. The region is characterized by a relatively flat landscape with alluvial plain
Alluvial plain
An alluvial plain is a relatively flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms...
s dissected by undulating hills or high terraces. The biota
Biota
Biota may refer to:* Biota , the plant and animal life of a region* Biota , a superdomain in taxonomy* Biota , an evergreen coniferous tree, Platycladus orientalis* Biota , an avant-prog band from Colorado, USA...
of the southwest Amazon moist forest is very rich because of these dramatic edaphic
Edaphic
Edaphic is a nature related to soil. Edaphic qualities may characterize the soil itself, including drainage, texture, or chemical properties such as pH. Edaphic may also characterize organisms, such as plant communities, where it specifies their relationships with soil...
and topographical variations at both the local and regional levels. This ecoregion has the highest number of both mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s and bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s recorded for the Amazonian biogeographic realm: 257 with 11 endemic species for mammals and 782 and 17 endemics for birds. The inaccessibility of this region, along with few roads, has kept most of the habitat intact. Also, there are a number of protected areas, which preserve this extremely biologically rich ecoregion.
Location and general description
Pastaza River
The Pastaza is a large tributary to the Amazon River.It has its headwaters in the province of Tungurahua, where the Tambo River joins the Latacunga River, near the foot of the Volcano Tungurahua, flowing south-east towards the Amazon Basin...
-Marañon
Marañón River
The Marañón River rises about 160 km to the northeast of Lima, Peru, flows through a deeply-eroded Andean valley in a northwesterly direction, along the eastern base of the Cordillera of the Andes, as far as 5 degrees 36' southern latitude; then it makes a great bend to the northeast, and...
and (2) Ucayali River sub-basins drain into the Upper Amazon River
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
in Peru; (3) the Acre and (4) Madre de Dios
Madre de Dios River
The Madre de Dios River, homonymous to the Peruvian region it runs through, then becomes the Beni River in Bolivia and then turns northward into Brazil, where it is called the Madeira River...
-Beni
Beni River
The Beni River is a river in the north of Bolivia.It rises north of La Paz and flows northeast through the pampas. One of the tributary rivers is Tuichi River in the Madidi National Park. Tuichi River joins the Beni River upstream from the town Rurrenabaque. South of Rurrenabaque, Río Beni runs...
sub-basins drain to the east into the Juruá, Purus and Madeira River
Madeira River
The Madeira River is a major waterway in South America, approximately 3,250 km miles long The Madeira is the biggest tributary of the Amazon...
s; which, in turn, feed into the Amazon River lower down in Brazil. The region is bisected north to south between Peru and Brazil by the small mountain range Serra do Divisor
Serra do Divisor National Park
Serra do Divisor National Park is a national park on the westernmost point of Brazil, in the state of Acre, near Peruvian border. It is also the highest point in that state, reaching 609 meters above sea level. It has been nominated by the Brazilian government as a Tentative World Heritage Site...
. It extends east to the edge of the Purus Arch, or ancient zone of uplift, in the southwestern area of the Brazilian State of Amazonas. It then extends southeast into northern Bolivia and in a narrow band south along the base of the Andes Mountains. Elevations range from 300 metres (984.3 ft) in the west to 100 metres (328.1 ft) on the eastern edge of the region. Because the ecoregion covers such a vast area, there are climatic, edaphic and floristic differences within it. Generally, the wetter and less seasonal northern forests (3000 millimetres (118.1 in) of rain annually) share only 44 percent of the tree species with forests in the slightly drier, more seasonal southern region. This region receives from 1500 to 2100 mm (59.1 to 82.7 in) of rain annually, in different parts. Temperatures over the year range from 22 to 27 °C (71.6 to 80.6 F).
Landforms present in this region include the upland terra firme (non-flooded) mostly on nutrient-poor lateritic soils
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...
, ancient alluvial plain
Alluvial plain
An alluvial plain is a relatively flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms...
s (mostly non-flooded) on nutrient-rich soils, and present alluvial plains (várzea
Várzea
-Portugal:* Várzea , a civil parish in the municipality of Amarante* Várzea , a civil parish in the municipality of Barcelos* Várzea , a civil parish in the municipality of Santarém-Other:...
, seasonally flooded) of super-rich sediments renewed with each annual flood. Floristically, distinct lowland humid forest types occur on each of these landforms with the terra firme mature forests and late successional, seasonally flooded forest being the two major types. Permanent swamp
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
forests are common on the alluvial plains. Pockets of nutrient-poor white sand
Coral sand
Coral sand is sand of particles originating in tropical and sub-tropical marine environments from bioerosion of limestone skeletal material of marine organisms. One example of this process is that of parrot fishes which bite off pieces of coral, digest the living tissue, and excrete the inorganic...
soils are found here that host forests of lower height, a more open forest canopy, and lower alpha diversity
Alpha diversity
Alpha diversity is the biodiversity within a particular area, community or ecosystem, and is usually expressed as the species richness of the area. This can be measured by counting the number of taxa within the ecosystem...
, but with many endemics. The forests are mostly dense tropical rain forest, but some patches of open forest exist.
At first glance, large areas may appear to be homogeneous dense forests with a canopy 30 to 40 m (98.4 to 131.2 ft) high with some emergent trees to 50 metres (164 ft) towering above the canopy. Structurally, this may be the case; however, the species composition reflects much the opposite: tree species variability reaches upwards to 300 species in a single hectare. There are a few exceptions to this high diversity, mainly where stands dominated by one or several species occur. The first are vast areas (more than 180000 square kilometres (69,498.4 sq mi)) dominated by the highly competitive arborescent bamboos Guadua sarcocarpa and Guadua weberbaueri near Acre, Brazil extending into Peru and Bolivia. Other monodominant stands include swamp forests of the economically important palms Mauritia flexuosa
Moriche Palm
The Moriche Palm, Mauritia flexuosa, also known as the Ité Palm, Ita, Buriti, or aguaje , is a palm tree. It grows in and near swamps and other wet areas in tropical South America....
and Jessenia bataua
Oenocarpus bataua
The patawa, sehe, hungurahua or mingucha is a palm tree native to the Amazonia, that produce eatable fruits rich in high quality oil.- Distribution and habitat:...
.
In the north of the region, some of the best known plants yield products of commercial value, such as rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
(Hevea brasiliensis), mahogany
Mahogany
The name mahogany is used when referring to numerous varieties of dark-colored hardwood. It is a native American word originally used for the wood of the species Swietenia mahagoni, known as West Indian or Cuban mahogany....
(Swietenia macrophylla
Swietenia macrophylla
Swietenia macrophylla, commonly known as big leaf mahogany, is a species of plant in the Meliaceae family. It is one of two species that yields genuine mahogany timber, the other being Swietenia mahagoni....
), balsam wood (Myroxylon balsamum), timber
Timber
Timber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
and essential oil
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...
(Amburana acreana
Amburana acreana
Amburana acreana is a species of legume in the Fabaceae family.It is found in Bolivia, Brazil, and Peru.It is threatened by habitat loss.-References:* Varty, N. & Guadagnin, D.L. 1998. . Downloaded on 18 July 2007....
), tagua nut (Phytelephas microcarpa), and strychnine
Strychnine
Strychnine is a highly toxic , colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine causes muscular convulsions and eventually death through asphyxia or sheer exhaustion...
(Strychnos asperula). An area representative of the southern part of this region, in the north of Bolivia, hosts a seasonal humid high forest to 35 metres (114.8 ft) with some emergents reaching 40 metres (131.2 ft) in height and many buttressed trunks. The largest trees are Ceiba pentandra, Poulsenia armata, Calycophyllum spruceanum, Swietenia macrophylla
Swietenia macrophylla
Swietenia macrophylla, commonly known as big leaf mahogany, is a species of plant in the Meliaceae family. It is one of two species that yields genuine mahogany timber, the other being Swietenia mahagoni....
, and Dipteryx odorata. Other trees typical in this area are Calycophyllum acreanum, Terminalia amazonica, Combretum laxum, Mezilaurus itauba
Mezilaurus itauba
Mezilaurus itauba is a species of plant in the Lauraceae family. It is found in Bolivia, Brazil, Ecuador, French Guiana, Peru, and Suriname.-Sources:...
, Didymopanax morototoni, Jacaranda copaia, Aspidosperma megalocarpon
Aspidosperma megalocarpon
Aspidosperma megalocarpon is a species of plant in the Apocynaceae family. It is found in Belize, Colombia, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Suriname, and Venezuela.-Source:...
, Vochisia vismiaefolia, Hirtella lightioides, and Hura crepitans. Palms include, among others, members of the genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Astrocaryum
Astrocaryum
Astrocaryum is a genus of about 36 to 40 species of palms native to Central and South America and Trinidad.-Description:Astrocaryum is a genus of spiny palms with pinnately compound leaves–rows of leaflets emerge on either side of the axis of the leaf in a feather-like or fern-like pattern. Some...
, Iriartea
Iriartea
Iriartea is a genus in the palm family Arecaceae, native to Central and South America. The best-known species – and probably the only one – is Iriartea deltoidea, which is found from Nicaragua south into Bolivia. It is the most common tree in many forests in which it occurs...
and Sheelea, Oenocarpus mapora, Chelyocarpus chuco, Phytelephas macrocarpa, Euterpe precatoria
Euterpe precatoria
Euterpe precatoria is a tall, slender-stemmed, pinnate-leaved palm native to Central and South America and Trinidad and Tobago. E. precatoria is used commercially to produce fruits.-Biological description:...
, and Jessenia bataua. Lianas are common with about 43 species present. Many Amazonian species reach the southern limit of their distribution here. The Brazil nut tree (Bertholletia excelsa) is present in the south, but is likely not native this far west in Amazonia.
Biodiversity features
What is distinctive about this region is the diversity of habitats created by edaphic, topographic and climatic variability. Habitat heterogeneity, along with a complex geological and climatic history has led to a high cumulative biotic richness. Endemism and overall richness is high in vascular plantVascular plant
Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the clubmosses, Equisetum, ferns, gymnosperms and angiosperms...
s, invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and vertebrate
Vertebrate
Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...
animals. This is the Amazon Basin’s center of diversity for palms. The rare palm Itaya amicorum is found on the Upper Javari River. This ecoregion has the highest number of mammals recorded for the Amazonian biogeographic realm: 257 with 11 endemics. Bird richness is also highest here with 782 species and 17 endemics. In the southern part of the Tambopata Reserve, one area that is 50 square kilometres (19.3 sq mi) holds the record for bird species: 554. On the white sand areas in the north, plants endemic to this soil type include Jacqueshuberia loretensis
Jacqueshuberia loretensis
Jacqueshuberia loretensis is a species of legume in the Fabaceae family.It is found only in Peru.-References:* World Conservation Monitoring Centre 1998. . Downloaded on 19 July 2007....
, Ambelania occidentalis, Spathelia terminalioides, and Hirtella revillae.
Many widespread Amazonian mammals and reptiles find a home in this region. These include tapir
Tapir
A Tapir is a large browsing mammal, similar in shape to a pig, with a short, prehensile snout. Tapirs inhabit jungle and forest regions of South America, Central America, and Southeast Asia. There are four species of Tapirs: the Brazilian Tapir, the Malayan Tapir, Baird's Tapir and the Mountain...
s (Tapirus terrestris), jaguar
Jaguar
The jaguar is a big cat, a feline in the Panthera genus, and is the only Panthera species found in the Americas. The jaguar is the third-largest feline after the tiger and the lion, and the largest in the Western Hemisphere. The jaguar's present range extends from Southern United States and Mexico...
s (Panthera onca), the world’s largest living rodents, capybara
Capybara
The capybara , also known as capivara in Portuguese, and capibara, chigüire in Venezuela, Colombia, and Ecuador ronsoco in Peru, chigüiro, and carpincho in Spanish, is the largest living rodent in the world. Its closest relatives are agouti, chinchillas, coyphillas, and guinea pigs...
s (Hydrochoeris hydrochaeris), kinkajou
Kinkajou
The kinkajou , also known as the honey bear , is a rainforest mammal of the family Procyonidae related to olingos, coatis, raccoons, and the ringtail and cacomistle. It is the only member of the genus Potos. Kinkajous may be mistaken for ferrets or monkeys, but are not closely related...
s (Potos flavus), and white-lipped peccaries (Tayassu pecari). Some of the globally threatened animals found in this region include black caimans (Melanosuchus niger) and spectacled caimans (Caiman crocodilus crocodilus), woolly monkeys (Lagothrix lagotricha), giant otters (Pteronura brasiliensis), giant anteaters (Myrmecophaga tridactyla), and ocelots (Leopardus pardalis).
Pygmy marmosets (Cebuella pygmaea), Goeldi marmosets (Callimico goeldii), pacaranas (Dinomys branickii), and olingos (Bassaricyon gabbii) are found here, but not in regions to the east. Other primates present include tamarins (Saguinus fuscicollis and Saguinus imperator), brown pale-fronted capuchins (Cebus albifrons), squirrel monkeys (Saimiri sciureus), white-faced sakis (Pithecia irrorata), and black spider monkeys (Ateles paniscus). The rare red uakari monkeys (Cacajao calvus) are found in the north in swamp forests. Nocturnal two-toed sloths (Choloepus hoffmanni) are well distributed throughout this region along with the widespread three-toes sloths (Bradypus variegatus). The Amazon River is a barrier to a number of animals such as the tamarins Saguinus nigricollis, which occur on the north side, and Saguinus mystax, which occurs on the southwest side of the Amazon-Ucayali system.
In the region of Manu, 68 species of reptiles and 68 species of amphibians have been reported for the lowland areas while 113 species of amphibians and 118 species of reptiles are reported from Madre de Dios, including the rare and interesting pit-vipers (Bothriopsis bilineata
Bothriopsis bilineata
Bothriopsis bilineata is a venomous pitviper species found in the Amazon region of South America. A pale green arboreal species that may reach a meter in length, it is an important cause of snakebite throughout the entire Amazon region...
, Bothrops brazili
Bothrops brazili
Bothrops brazili is a venomous pitviper species found in South America. The species was named in honor of Dr. Vital Brazil, a Brazilian physician and founder of the Instituto Butantan in São Paulo. No subspecies are currently recognized.-Description:...
), and frogs such as Dendrophidion sp., Rhadinaea occipitalis, and Xenopholis scalaris.
Current status
Deforestation
Deforestation is the removal of a forest or stand of trees where the land is thereafter converted to a nonforest use. Examples of deforestation include conversion of forestland to farms, ranches, or urban use....
is constrained to the few roads that do exist or around urban centers such as Iquitos
Iquitos
Iquitos is the largest city in the Peruvian rainforest, with a population of 370,962. It is the capital of Loreto Region and Maynas Province.Located on the Amazon River, it is only above sea level, although it is more than from the mouth of the Amazon at Belém on the Atlantic Ocean...
, Puerto Maldonado
Puerto Maldonado
Puerto Maldonado is a city in Southeastern Peru in the Amazon forest west of the Bolivian border on the confluence of the Tambopata and Madre de Dios River, a tributary of the Amazon River. It is the capital of the Madre de Dios Region....
, and Rio Branco
Rio Branco
Rio Branco is a Brazilian city, capital of Acre. Located in the Valley of Acre in northern Brazil, it is the most populous county in the state, with 305,954 inhabitants, according to a 2009 estimate - almost half the state population....
.
Manú National Park
Manú National Park
Manú National Park is a biosphere reserve located in Madre de Dios and Paucartambo, Cusco. Before becoming an area protected by the Peruvian government, the Manú National Park was conserved thanks to its inaccessibility. The park remains fairly inaccessible by road to this day. In 1977, UNESCO...
, a World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...
, protects 15328 square kilometres (5,918.2 sq mi) of pristine lowland forest in southern Peru, a large part of which falls into this ecoregion. The nearby Tambopata-Candamo
Tambopata-Candamo
Tambopata-Candamo is a nature reserve in the Peruvian Amazon Basin south of the Madre de Dios River in Tambopata Province's Inambari and Tambopata districts...
reserve protects seven major forest types. This reserve offers refuge to game species that have been over-hunted in other areas such as tapirs, spider monkey
Spider monkey
Spider monkeys of the genus Ateles are New World monkeys in the subfamily Atelinae, family Atelidae. Like other atelines, they are found in tropical forests of Central and South America, from southern Mexico to Brazil...
s, jaguars, capybaras, white-lipped peccaries, monkeys, caimans and river turtles. The Manuripi-Heath Amazonian Wildlife National Reserve
Manuripi-Heath Amazonian Wildlife National Reserve
Manuripi-Heath Amazonian Wildlife National Reserve is a protected area in the Pando Department, Bolivia, situated in the Manuripi Province and Madre de Dios Province.- External links :...
is located in the southernmost area of this region in Bolivia covering 18900 square kilometres (7,297.3 sq mi) of dense tropical forest. Several extractive reserves, the largest being Chico Mendes Extractive Reserve and Alto Juruá Extractive Reserve, are actively managed in Brazil. Other protected areas include national parks (Serra do Divisor National Park
Serra do Divisor National Park
Serra do Divisor National Park is a national park on the westernmost point of Brazil, in the state of Acre, near Peruvian border. It is also the highest point in that state, reaching 609 meters above sea level. It has been nominated by the Brazilian government as a Tentative World Heritage Site...
, Madidi National Park, Isoboro Secure National Park, Bahuaja-Sonene National Park
Bahuaja-Sonene National Park
The Bahuaja-Sonene National Park is located in south-eastern Peru. It contains the tropical forests and tropical foothills of Puno, dwarf forests, and the Heath Pampas. It was created in July 1996 out of the Tambopata-Candamo Reserved Zone and expanded on Sept...
), national forests, Rio Acre Ecological Station
Rio Acre Ecological Station
Rio Acre Ecological Station is an ecological station in Brazil....
, Antimari State Forest, Apurimac Reserve Zone, among others. Most protected areas suffer from insufficient administration and patrol.
Types and severity of threats
Hunting may be threatening populations of the tapir (Tapirus terrestris) and large primates in the north. Some habitat is threatened by expansion of the agricultural and pastoral frontier, gold miningGold mining
Gold mining is the removal of gold from the ground. There are several techniques and processes by which gold may be extracted from the earth.-History:...
, and selective logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
that erodes the genetic diversity of a few valuable timber species. The economically important palm Euterpe precatoria
Euterpe precatoria
Euterpe precatoria is a tall, slender-stemmed, pinnate-leaved palm native to Central and South America and Trinidad and Tobago. E. precatoria is used commercially to produce fruits.-Biological description:...
is being depleted in some areas by unsustainable palm heart extraction. A dramatic problem that exists in the Brazilian State of Acre and in the adjacent area of Peru is the spread of the invasive
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
Guadua
Guadua
Guadua is a Neotropics genus of thorny clumping bamboo, ranging from moderate to very large species. Physically, Guadua angustifolia is noted for being the largest Neotropics bamboo. The genus is similar to Bambusa and is sometimes included in Bambusa...
bamboo forests. This highly competitive bamboo invades and dominates abandoned clearings and threatens to dominate the disturbed areas in this region. Logging along major rivers and near urban centers has decimated populations of mahogany (Swietenia macrophylla
Swietenia macrophylla
Swietenia macrophylla, commonly known as big leaf mahogany, is a species of plant in the Meliaceae family. It is one of two species that yields genuine mahogany timber, the other being Swietenia mahagoni....
), tropical cedar (Cedrela odorata
Cedrela odorata
Cedrela odorata . The genus Cedrela has undergone two major systematic revisions since 1960. The most recent revision reduced the number of species in the genus to seven . The common cedro, Cedrela odorata L., embraces 28 other named species, including C. mexicana M. J...
), and kapok (Ceiba pentandra).
Further reading
- Daly, D. C., and J. D. Mitchell. 2000. "Lowland vegetation of tropical South America". Pages 391-453 in D. L. Lentz, editor, Imperfect Balance: Landscape Transformations in the Precolumbian Americas. New York: Columbia University Press. ISBN: 0231111568
- Ducke, A., and G. A. Black. 1953. "Phytogeographical Notes on the Brazilian Amazon". Anais da Academia Brasileira de Ciências 25: 1-46.
- Ergueta S.P., and J. Sarmiento. 1992. "Fauna silvestre de Bolivia: diversidad y conservación". Pages 113-163 in M. Marconi, editor, Conservación de la Diversidad Biológica en Bolivia. La Paz, Bolivia: CDC-Boliva and USAID.
- Fundação Instituto Brasilero de Geografia Estatástica-IBGE. 1993. Mapa de vegetação do Brasil. Map 1:5,000,000. Rio de Janeiro, Brazil.
- Henderson, A. 1995. The Palms of the Amazon. New York: Oxford University Press. ISBN: 0195083113
- Instituto Geográfico Nacional. 1987. Ecoregiones del Peru. Map 1:5,000,000. Atlas del Peru, Lima, Peru.
- Pacheco, V., and E. Vivar. 1996. "Annotated checklist of the non-flying mammals at Pakitza, Manu Reserve Zone, Manu National Park, Perú." Pages 577-592 in D. E. Wilson and A. Sandoval, editors, Manu: The Biodiversity of Southeastern Peru. Washington, DC: Smithsonian Institution.
- Peres, C. A. 1999. "The structure of nonvolant mammal communities in different Amazonian forest types". Pages 564-581 in J. F. Eisenberg and K. H. Redford, editors, Mammals of the Neotropics: the Central Neotropics. Chicago: University of Chicago Press. ISBN: 0226195422
- Räsänen, M. 1993. "La geohistória y geología de la Amazonia Peruana". Pages 43-67 in R. Kalliola, M. Puhakka, and W. Danjoy, editors, Amazonia Peruana: vegetacióon húmeda tropical en el llano subandino. Turku: PAUT and ONERN.
- Ribera Arismendi, M. 1992. "Regiones ecológicas." Pages 9-71 in M. Marconi, editor, Conservación de la Diversidad Biológica en Bolivia. La Paz, Bolivia: CDC-Boliva and USAID.
- Ribera, M.O., M. Libermann, S. Beck, and M. Moraes. 1994. Mapa de la vegetacion y areas protegidea de Bolivia. 1:1,500,000. Centro de Investigaciones y Manejo de Recursos Naturales (CIMAR) and Universidad Autónoma Gabriel Rene Moreno (UAGRM), La Paz, Bolivia.
- Silva, J.M. C. 1998. Um método para o estabelecimento de áreas prioritárias para a conservação na Amazônia Legal. Report prepared for WWF-Brazil. 17 pp.