A treeless area between the icecap and the tree line of Arctic regions, having a permanently frozen subsoil and supporting low-growing vegetation such as lichens, mosses, and stunted shrubs.

• 苔原:北极地区冰盖和乔本植被线之间的无树地区,有永冻底土,并支撑低的植物,如苔藓、地衣和发育不全的灌木。