[2] The biota of the southwest Amazon moist forest is very rich because of these dramatic edaphic and topographical variations at both the local and regional levels.

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.

Landforms present in this region include the upland terra firme (non-flooded) mostly on nutrient-poor lateritic soils, ancient alluvial plains (mostly non-flooded) on nutrient-rich soils, and present alluvial plains (várzea, seasonally flooded) of super-rich sediments renewed with each annual flood.

In the north of the region, some of the best known plants yield products of commercial value, such as rubber (Hevea brasiliensis), mahogany (Swietenia macrophylla), balsam wood (Myroxylon balsamum), timber and essential oil (Amburana acreana), tagua nut (Phytelephas microcarpa), and strychnine (Strychnos asperula).

Other trees typical in this area are Calycophyllum acreanum, Terminalia amazonica, Combretum laxum, Mezilaurus itauba, Didymopanax morototoni, Jacaranda copaia, Aspidosperma megalocarpon, Vochisia vismiaefolia, Hirtella lightioides, and Hura crepitans.

Palms include, among others, members of the genera Astrocaryum, Iriartea and Sheelea, Oenocarpus mapora, Chelyocarpus chuco, Phytelephas macrocarpa, Euterpe precatoria, and Jessenia bataua.

In the southern part of the Tambopata Reserve, one area that is 50 square kilometres (19 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, Ambelania occidentalis, Spathelia terminalioides, and Hirtella revillae.

[2] These include tapirs (Tapirus terrestris), jaguars (Panthera onca), the world's largest living rodents, capybaras (Hydrochoerus hydrochaeris), kinkajous (Potos flavus), and white-lipped peccaries (Tayassu pecari).

[2] People have dwelled along the major rivers for millennia and have subtly altered the forests on a small scale, but around the urban centers development proceeds.

Manú National Park, a World Heritage Site, protects 15,328 square kilometres (5,918 sq mi) of pristine lowland forest in southern Peru, a large part of which falls into this ecoregion.

The Manuripi-Heath Amazonian Wildlife National Reserve is located in the southernmost area of this region in Bolivia covering 18,900 square kilometres (7,300 sq mi) of dense tropical forest.

[2] Some habitat is threatened by expansion of the agricultural and pastoral frontier, gold mining, and selective logging that erodes the genetic diversity of a few valuable timber species.

A dramatic problem that exists in the Brazilian State of Acre and in the adjacent area of Peru is the spread of the invasive Guadua bamboo forests.

Logging along major rivers and near urban centers has decimated populations of mahogany (Swietenia macrophylla), tropical cedar (Cedrela odorata), and kapok (Ceiba pentandra).