Typical species of this zone is Bosnian pine. This rare kind of pine occurs sporadically higher than 1,000 metres and gradually replaces the black pine, while over 1,400 metres it creates an almost unmixed forest. Οver 2,000 metres the forest becomes sparser, reaching to 2,750 metres, thus creating one of the highest forest tree line limit (limit of forest growth) in the Balkans and Europe. Another feature of this zone is that over 2,500 metres the trees appear in a crawling form. The region, where Bosnian pine grows, is mostly dry and its slopes are rocky. There are no springs or water streams. The vegetation growing there is adapted to specific local conditions and represented by typical shrubs, graminaceous, chasmophytes etc., while the flora includes many endemic species of the Balkans.