The site lies in the valley of the Luachimo river, near the town of Dundo (specific area not identified by Huntley 1974b). The area lies within the 1,400 mm isohyet, with markedly summer rainfall. The vegetation is gallery forest along the river, surrounded by extensive grassy plains and open woodland. Canopy height of the gallery forest is 20–40 m, and the tree species composition of this habitat includes Piptadeniastrum africanum, Chlorophora excelsa, Ceiba pentandra, Musanga cecropioides, Allanblackia floribunda and Entandophragma angolensis. Trees and shrubs are scattered through the extensive tall grassland that edges the gallery forests. Huntley and Matos (1994) suggest that this woodland contains a selected subset of fire-resistant or fire-tolerant tree species that includes Hymenocardia acida, Erythrina abyssinica, Piliostigma thonningii and Cussonia angolensis.
See Box and Table 3 for key species. The structurally diverse vegetation supports a rich avifauna that is fairly well-known, and a total of 313 species have been collected at Dundo and along the Luachimo river. The site is rich in species of the Guinea–Congo Forests biome. This is one of the few sites (in some cases, the only site) in Angola south of the Congo river where Caprimulgus climacurus, Halcyon malimbica, Alcedo quadribrachys, Gymnobucco bonapartei, Indicator conirostris, Cossypha polioptera, Cossypha niveicapilla, Ficedula albicollis, Fraseria ocreata, Fraseria cinerascens, Illadopsis fulvescens, Ptyrticus turdinus, Laniarius leucorhynchus, Ploceus superciliosus, Parmoptila woodhousei, Pyrenestes ostrinus, Hypargos niveoguttatus and Clytospiza monteiri have been recorded. Telacanthura melanopygia has been collected near Dundo (Pinto 1973a) and is likely to occur in the proposed protected area on the Luachimo river. Two species of the Afrotropical Highlands biome occur at the site.
Non-bird biodiversity: Dundo is the type-locality of the rare bat Micropterus grandis (Cabral 1989), and other rare bats that occur in gallery forest along the Luachimo river include Megaloglossus woermanni and Hypsignathus monstrosus (Cabral 1989). Larger mammals that have been recorded include Aonyx congicus (DD) and Lycaon pictus (EN) (Cabral 1987; Cabral and Simões 1988).
Pressure/threats to key biodiversity
This is one of the areas proposed by Huntley (1974b) and Huntley and Matos (1994) as a priority protected area to conserve a good representative sample of this unusually species-rich gallery forest habitat. Current threats to the biodiversity and the avifauna in particular include very extensive surface-diggings for diamonds by local people. No other threats are known, but are likely to include hunting and slash-and-burn cultivation.