The ecoregion includes the area north and east of the Lake Khanka Lowlands, which separate it from the Changbaishan ecoregion. Mixed broadleaf-coniferous forests extend to the north Primorsky and South-east Khabarovsky Province of Russia, and in the west include the Wanda Mountains in the middle reach of the Wusuli-Ussuri River in China's Heilongjiang Province.
For most of the Sikhote-Alin Mountains, the lower forest belts (250-350 m asl) are made up primarily of mixed broadleaf species such as Manchurian ash (Fraxinus mandshurica), Japanese elm, and Japanese poplar (Populus maximowiczii). Species composition changes abruptly to Korean pine (Pinus koraiensis) and broadleaf forests up to 700 m. Typical groundcover in the forest understory includes ginseng (Panax ginseng), a highly sought-after medicinal plant that is now severely depleted. The highest elevation belt of true trees consists mainly of Khingan fir and Ajan spruce forests up to 1,300 m. Higher still – at about 1,400-1,500 m – stands of Erman’s birch and dwarf shrubs are interspersed with Manchurian alder (Alnus mandshurica) and subalpine meadows. Mountain tundra of shrubs, lichens, and grasses is found on some of the tallest mountains in the region.
The Sikhote-Alin Mountains form the southern boundary for boreal species such as ermine (Mustela erminea), wolverine (Gulo gulo), adder (Vipera berus), and chestnut bunting (Emberiza rutila). At the same time, the mountains are the northernmost habitat of subtropical species such as the Amur tiger and the Leopard cat (Felis leuptilura\Prionailurus bengalensis).
This ecoregion is widely known as the last stronghold of Amur tiger, with about 400 animals (90% of the remaining wild population) residing within its bounds. However, historical records from the late 19th and early 20th centuries show that prior to large-scale human encroachment the more dense tiger populations inhabited the Changbaishan ecoregion.
The three most prominent protected areas involved in long-term research of the ecoregion are Sikhote-Alinsky Zapovednik in the north, Lazovsky Zapovednik on the Pacific seacoast, and Ussurisky Zapovednik in the south.
"Bear" Hunting Estate. Sikhote Alin' Mountains. Primorsky Province. (Photo by P.Fomenko)