Identity:

Formations of the timberline of mountains, in which subalpine forests give way to alpine or boreal heaths and scrubs, or to alpine grasslands; they are characterised by a scattering of stunted, gnarled trees punctuating an alpine shrub or grassland environment, by a macromosaic of alpine shrub and grass formations with scattered islands of forest, or by open or clear forest with an undergrowth composed of alpine elements such as ericaceous shrubs. They occupy a narrow belt, varying in altitudinal location according to latitude, exposure and other climatic or edaphic conditions. Component habitats include those of F2 and E4.