ABSTRACT
Biodiversity should always be regarded as the result of evolution within given biota. The three-dimensional structure of mountain regions and the relevant ecological situation govern this process. Floristic investigation of the major regions in Eurasia has been intensive and has led to a good knowledge of the flora of the relevant mountains. The species numbers can be obtained by reference to the various floras of each region. However, in most cases, it is not possible to provide relevant data for distinct mountain regions or altitudinal belts. The data on the flora and species distribution can be analysed according to chorological types as well as life form spectra. In arid mountains lacking any forest belt or forest patches, the maximum percentage of endemism occurs in the foothills of the mountains. In mountains with forest patches those, together with the rich vegetation mosaic of this belt, are the main sites rich in endemism.
