Vegetation Structure in the High Mountains of the Balkan Peninsula and the Caucasus, USSR^∗

Abstract

The high-mountain vegetation of the Balkan Peninsula and of the Caucasus are compared. Due to the higher absolute altitude of the Caucasus, there is a greater richness and more abundant variety of its vegetation. Only about 50 to 60 species are established to be common to high mountains of both regions, and the greater part of these are widely distributed arctic-alpine taxons. On the level of genera and of the ecology of major formations, there are many analogies and similarities resulting from the common origin of the flora of the two regions which derives from the ancient Mediterranean. At the species and plant-association level, in contrast, great differences and high endemism mark the high-mountain species and communities of each region. This results from their ancient isolation. Only three formations with common dominants are found in the higher mountain vegetation belts: Festucetum variae, Nardetum strictae, and Eriophoretum vaginati. For the Balkan Peninsula, the subalpine belt of dwarf-pine elfin-wood formations is characteristic (except Greece). In the Caucasus they are entirely absent, being replaced by birch crook-stem forests with an undergrowth of Rhododendron spp. which, in turn, are not found in the Balkan Peninsula. This indicates a close connection between the Caucasus and the Himalayas. The upper forest belt in each region consists of vicarious species of the same arboreous genera. Three schemes are given here for the comparison of the vegetative cover: Scheme 1 for the high-mountain belts of the humid, central part of the Balkan Peninsula and the northwest Caucasus; Scheme 2 for the dry, high-mountain regions—karstic terrain in the Balkan Peninsula and interior, dry valleys in the Caucasus; Scheme 3 for the east slopes within the Submediterranean Zone (with subtropical vegetation in the lower belts)—in central Greece and the Caucasian Hyrcanian province.