Selenge-Orkhon forest steppe
This ecoregion is characterized by a sparse distribution of forests at higher elevations, wide mountain valleys in the Orkhon and Selenge river basins. The open steppe vegetation is a combination of pine (Pinus silvestris) and aspen (Populus tremula) amidst steppe flora. Notable fauna are rodents such as mountain hare (Lepus tolai), Korean field mouse (Apodemus peninsulae), and squirrel (Sciurus vulgaris) and birds such as Dalmation pelican (Pelicanus crispus), white spoonbill (Platalea leucorodia), and black stork (Ciconia nigra). Principal threats are heavy settlement by herders, wide-spread animal husbandry, and pressures from railways, roads, and industrial processing.
Location and General Description
This ecoregion lies between the steppe and the taiga and includes the Orkhon and Selenge river basins. Average altitude of the mountains in the ecoregion is 1500-2000 meters (m) while mean altitude of the larger area is 800-1200 m. Groves, with areas of saline soil, continue into the vast mountain valley steppe. The northern and northwestern portions of the mountains that surround the basin support broadleaf forests. At lower altitudes the forests are dominated by Rosa acicularis while Cotoneaster melanocapra are rare. Due to the landscape and humid climate caused by forest in delta of the Selenge River, there are gray, gray-muddy, and dark-gray soils.
The Orkhon-Selenge forest steppe experiences a dry climate similar to neighboring steppe regions. The hot, dry wind coming from the northeast steppe areas maintains the unique characteristics of the Orkhon-Selenge forest steppe. The winter season in the basin continues from mid-October to late March or early April. The average air temperature in January is –20° Celcius (C) to –25° C. Spring starts in early April and finishes late June. Strong winds and sudden cold continue to occur regularly until June. The summer season starts from mid-June and lasts 80-90 days. Summer precipitation is 250-300 millimeters (mm) while fall and winter precipitation is 150-200 mm. Fall starts mid-September and lasts about 65 days.
Coniferous forests are found on the northern slopes of the region’s mountains while the southern slopes are covered with open steppe vegetation. The open steppe vegetation is a combination of forest and steppe flora, including species such as pine (Pinus silvestris) and aspen (Populus tremula).
Dry steppe vegetation communities represent about 88 percent of the total area. Stipa cleistogenes is found in approximately 40 percent of the area while in highly elevated areas herbs such as Cleistogenes gramineae are prevelant. Caragana stipa is distributed in small patches throughout the ecoregion. A unique feature of this ecoregion is small sandy areas with their own distinct floral composition. These sandy areas are characterized by trees such as Ulmus pumila, Populus tremula, and Padus asiatica, and several willow species (Salix pentandra, S. tenuifolia) in wetter locations.
The fauna of this ecoregion is characteristic of species found in the forests and steppes of the greater geographic region. The steppe areas are particularly rich in species diversity. All steppe areas are inhabited by numerous rodent species. The main representatives are the mountain hare (Lepus tolai), Korean field mouse (Apodemus peninsulae), squirrel (Sciurus vulgaris), and root vole (Microtus oeconomus). Other notable species are the Siberian chipmunk (Tamias sibiricus) and the Zabaikalian wild boar (Sus scrofa). The forest steppe areas are visited in winter by wolves (Canis lupus) and by bears (Ursus arctos) during migration.
In the Selenge river basin there are 18 species of birds included in the Mongolian Red Data Book. Prominent species include: dalmation pelican (Pelicanus crispus), white spoonbill (Platalea leucorodia), black stork (Ciconia nigra), whooper swan (Cygnus cygnus), swan goose (Anser cygnoides), osprey (Pandion haliaetus), white-tailed eagle (Haliaeetus albicilla), Altai snowcock (Tetraogallus altaicus), white-naped crane (Grus vipio), Siberian crane (Grus Leucogeranus), Asiatic dowitcher (Limnodromus semipalmatus), great black-headed gull (Larus ichthyaetus), Hodgson’s stonechat (Saxicola insignis), Eurasian penduline (Remiz pendulinus), and Henderson’s ground jay (Podoces hendersoni).
Except for several smaller protected areas there is no broad protection for the ecological integrity of this region. The area is heavily settled by herders and animal husbandry is practiced widely. The low valleys of the Selenge basin are arid and fertile are used extensively for agriculture, hay making and livestock harvesting.
Types and Severity of Threats
The human population centers (e.g., Erdenet, Hutol and other county centers) in the region also bring associated industrial threats. Pressures resulting from railways, roads, and processing industries such as copper and cement are perhaps the most significant threat to this ecoregion and nature in Mongolia.
Justification of Ecoregion Delineation
This steppe lies mostly in Mongolia between the Khangai and Khentii mountains. It is distinguished from the Daurian forest steppe as that ecoregion which plays a unique role as an area of biological exchange for the flora and fauna of Siberia and middle Asia. In Mongolia, the ecoregion boundaries are derived from the mountain forest steppe surrounding the Selenge and Orkhon. In Russia, ecoregion boundaries conform to the forest steppe zone within the Tuva-Buryat-Mongolian vegetation province in Kurnaev’s forest map of the USSR.
Additional information on this ecoregion
- For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
- To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion.
- World Wildlife Fund Homepage
- Dulamtseren, S., and D. Tsendjav. 1989. Mammals of Mongolia, Ulaanbaatar (in Mongolian).
- Finch, C., editor. 1999. Mongolia's wild heritage. Mongolia Ministry for Nature and Environment, UNDP, GEF and WWF. Avery Press, Boulder. ISBN: 0937321044
- Gunin, P. D., E. A. Vostocova, and E. N. Matushkin. 1998. Preservation of ecosystems of inner Asia. Russian-Mongolian joint complex expedition, Moscow (in Russian).
- Hilbig, W. 1995. The Vegetation of Mongolia. SPB Academic Publishing, Amsterdam.
- Kurnaev, S. 1990. Forest regionalization of the USSR (1:16,000,000). Department of Geodesy and Cartography, Moscow.
- Murzae, E. M. 1962. Geography of Mongolian People’s Republic, Moscow (in Russian).
- Priobrajenskii, V. S., H. B. Fadeeva, L. E. Muhina, and G. M. Tomilov. 1959. Location forms and natural regionalization of Buriat ASSR, Moscow (in Russian).
- Sokolov, V. E. and A. Bold, editors. 1996. Rare species of Mongolia (vertebrates), Moscow (in Russian).
- Tsevegmed, S. 1969. Geography of Mongolia, Ulaanbaatar (in Mongolian).
- Ulziikhutag, N. 1989. Flora of Mongolia, Ulaanbaatar (in Mongolian).
- UNDP. 1998. Biological Diversity of Mongolia (National Report). MNE, UNDP, GEF, Ulaanbaatar.
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