ABSTRACT
The island concept can be applied to terrestrial as well as to marine ecosystems. Terrestrial or ‘continental habitat’ islands are those relatively small areas of land or water surrounded by, and isolated from, larger ecologically similar areas by an extensive area of dissimilar habitat. Isolation of Arctic from alpine and of alpine islands favoured the subsequent evolution of mountain endemics. Although some alpine plant species have a wide range of distribution such that they can be found in both hemispheres, most are spatially restricted to a few mountain systems. The close genetic relationship between the Arctic flora and that of the alpine zone of the north temperate mountains of Eurasia and North America has long been recognised. The diversity and isolation of mountain habitats are reflected in that of a wide range of distinctive human societies whose ways of life reflect an early and close adaptation to the particular problems created by a spatially variable and difficult physical environment.
