A natural habitat is a region with specific light, temperature, soil, bedrock, etc., inhabited by specific plant, animal, fungi and microorganism species. These characteristics are constant for every habitat type. Habitats are classified according to the plant communities in them. In Bulgaria, there are marine, coastal, grassland, shrubland, forest, rocky and cave, freshwater and marsh and peatland habitats.
The diverse climate, hydrological regime, soil and plant cover make the diversity of habitats in Bulgaria possible. The country is among the 5 richest in different habitat types in Europe. Around 37% of the habitats, deemed of high conservational priority in the EU are found in Bulgaria. These include the rarest and most fragile ones in Europe.
The condition of a natural habitat is considered favourable, when the area it covers remains constant in size or increases, when its structure and functions are stable and when the condition of its typical species is good.
Natural habitats in Europe are declining in area and are in increasingly worst condition, because of excessive use or abandonment of traditional practices in pastures and meadows, drying out and pollution of bodies of water, entry of alien and invasive animal and plant species, urbanization, destructive fishing practices in seas and oceans, etc. These are serious habitat threats.