| Ecoregion: Helanshan montane conifer forests | |
| Map: | Ecoregion PA0508.png |
| Map Size: | 300 |
| Map Alt: | Ecoregion territory (in purple) |
| Ecozone: | Palearctic |
| Biome: | temperate coniferous forests |
| Area: | 24605 |
| Countries: | China |
| Coordinates: | 38.9°N 163°W |
The Helanshan montane conifer forests ecoregion (WWF ID: PA0508) covers an isolated, forested mountain range surrounded by desert and semi-arid basins. As such, it has been called a "mountain island in the sky", and supports endemic species of plants and animals.[1] [2] The region supports the endangered Helan Shan pika.
See main article: Helan Mountains. The Helan Mountains ecoregions lies to the east of the Alashan Plateau semi-desert ecoregion, and to the west of the Ordos plateau steppe ecoregion. It is thus surrounded by arid basins. The mountain range is 180 km long, and reaches a peak altitude of 3,556 meters. The lower valleys between ridges are less forested.
The climate of the ecoregion is cold semi-arid (Köppen climate classification (BSk)). This climate is generally characterized as a 'steppe' climate, with precipitation greater than a true desert, and also a colder temperature.[3] [4]
Within the ecoregion, tree cover depends on the altitude zone. The lower slopes of the mountains are semi-arid, supporting short Siberian elm (Ulmus pumila) trees near intermittent streams. The valleys also support stands of Chinese red pine (Pinus tabuliformis). Higher on the hillsides are drought-adapted shrubs of rose, elm, caranga, ostryopsis (a type of birch tree), and juniper. At the highest elevations, tree cover is mostly dragon spruce (Picea asperata), birch and poplar.[1]