In terms of biogeography the park falls within both the Balkan mixed forests, and the Euxine-Colchic deciduous forests terrestrial ecoregions of the Palearctic temperate broadleaf and mixed forest. The combination of climate, specific geographic position and relief, as well as the lack of a strong anthropogenic influence, have contributed to the formation of 130 different habitats, making Strandzha Nature Park first in that indicator among all protected areas in Europe. There are 1670 species of vascular plants which constitute 44% of the total number of species in Bulgaria.