Daurian Steppe Ecoregion

Mongolian Section of The Amur/Heilong Ecoregion Complex (AHEC)

• Total area size: 235,000km2 (15 % of Mongolian territory and about 11% of the total Amur River basin).
• The Mongolian part of the Amur River basin consists of four main rivers: The Onon, Ulz, Kherlen, and Khalkh Gol.
• The Mongolian portion of the AHEC also has a large overlap with the Mongolian part of the Daurian Steppe (a WWF Global 200 Eco-region).

Eastern Region (Zuun Bus) Of Mongolia
The three easternmost Aimags or provinces of Hentiy, Dornod, and Sukhbaatar – make up an economic zone of Mongolia known as the Zuun Bus. A 100,500 square mile (250,000 ha) swath of land inhabited by fewer than 200,000 people, the Zuun Bus is also one of the most ecologically important regions on the face of the Earth.

Daurian Steppe Ecoregion
This is one of the best, most intact examples of Eurasian steppe and grasslands. The Daurian Steppe Eco-region encompasses a large portion of Eastern Mongolia, as well as parts of the Russian Far East and North-Eastern China. The region has distinct flora and fauna, with a number of endemic species.

The Onon River Basin
Within the Onon River basin, the region is an important catchment area forming the headwaters of the Amur/Heilong River.  The Onon River and its tributaries directly drain into the Amur through the Shilka River, all of which are ultimately destined for the Pacific Ocean. The Onon River originates on the North-East slope of the Khentii Mountain range. The total length of the Onon River is 808km with 298km flowing through Mongolian territory.

The Onon-Balj National Park

• One of WWF Mongolia’s priority protected areas, contained wholly in the AHEC and largely in the Daurian Steppe, is the Onon-Balj National Park.
• Established in 2000, the area is of outstanding natural beauty with rich forests and water courses. 
• The total area of the Park is around 400,000ha. This covers the soums (territories) of Dadal, Bayan-Adarga, Binder and Norovlin within Khentii aimag (province) and Bayan-Uul soum in Dornod aimag (see Figure 2).
• It occupies the territories of the culturally rich and traditional Buriad communities, a minority ethnic group of Mongolia.
• Climate of  the National Park is harsh continental, with mean annual air temperature varying from +0.50 to +30 С. 
• Forest area covers around 40% (160,000ha) of the Onon-Balj national park.
• Biodiversity of the National Park is unique and rich due the to its location in the transitional zone – from Siberian taiga to Duarian and Manchurian dry steppe.