Bulgaria is situated on a biogeographical cross-road, and therefore its nature, which has a greatest similarity with that of Central Europe, is considerably influenced by the fauna and the flora of the East European and the Asia Minor steppe, of the Mediterranean, and even of the transmarine Colhida. Situated in the middle of this cross-road the Balkan Mountain divides the country into two conditionally equal parts in equatorial direction.
The Balkan Mountain occupies almost quarter of Bulgaria's territory. Striking landscapes, remarkable land forms and a great part of bio diversity are preserved in protected areas. They comprise over one fourth of the surface of the national system of such areas.
Three parks of international conservation importance are situated in Balkan Mountain: Vratchanski Balkan National Park, Central Balkan National Park and Sliven Mountain Park.
The Balkan and fore-Balkan chain
The nature of the region is not homogeneous. The fore-Balkan consist of low mountain hills, rarely exceeding 1,000 m above sea level, as well as hilly lands representing a continuation of the Danube plain. The average altitude of the fore-Balkan is about 350 m.
Floristic and faunistic diversity is not the same everywhere in the chain. Today the fore-Balkan wood are mainly offshoot, a result of the millennial human activity. The shrubbery woods of Eastern hornbeam have spread secondary. The aurochs, the bison, the wild horse have disappeared forever. In spite of these losses caused by man in the past, the flora of the Fore-Balkan continue to be reach.
The red deer, the roe-deer, and the boar are quite numerous, the fallow-deer has been re-acclimatized. The jackal restored its habitants here in the last decades. The wolf is still rare, but the otter occurs in each in each of the river systems crossing the fore-Balkan. The nesting birds species are over 130.
The region is crossed by the midstreams of the rivers flowing into the Danube.
East, Middle and Western part of Balkan mountain
The altitude of the main Balkan Mountain chain is a prerequisite for its greater biological diversity as compared to the fore-Balkan. The nature of the 550 km long mountain is not homogeneous. West and Middle Balkan could be described together, the most eastern part of the chain ending on the sea coast are markedly distinct. The mountain never reach 700 m above sea level to the east of the Luda Kamtchia river defile and the climate is Mediterranean. The vegetation of the steppe type is seen in the southern branches of East Balkan.
There is a great number of peaks rising above 2,000 am in the West and especially Middle Balkan. The oak wood typical of the hilly plains have a weak distribution in the West and Middle Balkan as they rarely rise to more than 600 m. The mixed deciduous forests spread to 1,000 m above sea level on average.
Above them the common beech becomes dominant, its forests reaching 1,700 m and even higher in some places occasionally. Mixed forests of beech and fir are preserved in several regions mainly in the Middle BAlkan. The spruce forests usually occupy the altitude between 1,550 and 1,900 m. The sub alpine belt is well developed only in the four highest Balkan areas and is dominated by the communities of juniper, the whortleberries and the meadows.
