The Nakai–Nam Theun National Biodiversity Conservation Area (NBCA), located in Laos, comprises one of the most pristine wildernesses remaining in Southeast Asia. Nakai–Nam Theun NBCA covers approximately 3,445 km2 of the Annamite mountains and the adjacent Nakai Plateau in the provinces of Khammouane and Bolikhamxay. The reserve headquarters is located in Nakai, the capital of Nakai District.
From north to south, riversheds in the conservation area consist of those of the following rivers (Robichaud 2005).
- Nam Kata (eastern part only; the Nam Houay, on which the town of Na Kadok is located, is a tributary)
- Nam Xot
- Nam Mon
- Nam Theun
- Nam Noy
- Nam Pheo (a tributary of the Nam Noy)
- Nam One
All are tributaries of the Nam Theun to the southwest in the Nakai Plateau.
A series of surveys conducted since 1994 by the co-operative programme of the Wildlife Conservation Society (WCS), the Lao Department of Forestry, and the World Conservation Union (IUCN) have revealed that the area has an extremely high biodiversity conservation value. Semi-evergreen forest, deciduous dipterocarp forest and stands of pine are all found on the Nakai Plateau and in the Annamite foothills to the east, grading into more exclusively evergreen forests as the land rises towards the Vietnamese border. Higher still, huge areas of montane fagaceous forest cloak the slopes, interspersed with patches of Fokienia hodginsii, a commercially valuable cypress-like conifer. On mountain-tops and above c. 2,000 m the fagaceous forest gives way to more stunted, rhododendron-dominated ericaceous cloudforest.
Species of mammals, some discovered relatively recently, include the following (Robichaud 2005).
- Giant muntjac
- Roosevelt's muntjac
- Truong Son muntjac
- Indo-chinese warty pig
- Heude's pig
- Annamite striped rabbit
- Javan rhinoceros (Rhinoceros sondaicus annamiticus)
- Indochinese tiger
- Asian elephant
More than 400 bird species have been conclusively identified in Nakai–Nam Theun and the adjacent northern extension. This is by far the highest avian species richness of any site yet surveyed in Laos and is the highest recorded in a single protected area in South-East Asia.
Many endangered Vietic languages are spoken in the Nakai–Nam Theun Conservation Area. The Vietic peoples are the autochthonous peoples of the Nakai–Nam Theun area, and have deep knowledge of the local ecology. The Saek language, which preserves many archaic phonological features not found in any other Tai language, is also spoken in the area, often alongside Vietic languages in the same villages (Chamberlain 1998). Saek speakers had lived in the area for about 300 years, and had originally come from Vietnam. Bru speakers had moved to the area in the 1800s and 1900s, and now make up the majority of the population. Lao and Vietnamese speakers, most of whom are recent migrants, are also located in the area.
There is only one main road which enters the heart of the NPA, and it is via Route 8B (around Ban Kengdaeng, Khamkeut District) to Ban Thamuang (on the Nam Sot) to Ban Navang (on the Nam Mon). The Nakai Plateau can also be accessed from Thakek via Route 12 and then Route 8 B to Nakai District Town and the Nakai Plateau.
Notes and references
- Robichaud, William G. 2005. Testing assumptions: the recent history of forest cover in Nakai-Nam Theun National Protected Area, Laos. Masters dissertation. University of British Columbia.