Alpine Plant Diversity: A Global Survey and Functional Interpretations

Abstract

High-altitude vegetation is often treated as a special type of tundra, but this is an inadequate simplification. The major common features of real tundra and “alpine vegetation” are the absence of trees, the short stature of plants, and the low annual mean temperature. Most other components of the alpine environment may differ substantially from arctic tundra environments (Table 1; Bilhngs 1973, 1979a). The term “alpine” is used here exclusively for the vegetation above the natural subalpine tree line. Often this boundary is unsharp and is fragmented over several hundred meters of altitude. Where an upper tree line is missing, as in many arid mountain regions, the approximate level of the tree hne in the nearest more humid mountains is taken as a rough guidehne. At the polar end of the alpine vegetation, there is no clear distinction between the arctic-alpine and the arctic-lowland flora. Depending on region, most arctic-alpine vegetation north of 65° to 70°N is possibly better included in the term arctic (similar climate and species composition).