Slovenia's biodiversity has been exceptionally well preserved (through the Natura 2000 Network and other protected areas, such as national, regional and landscape parks). Of all the European Union Member States, Slovenia boasts the biggest share of Natura 2000 sites, as 37% of its territory is covered by Natura 2000.  

Slovenia is home to 140 animal and plant species out of 900 protected species that are rare or threatened in the European Union. In other words: as many as 15% of these plant and animal species are present in an area constituting 0.5% of the European Union's territory. Among them is the brown bear – the largest animal (it weighs more than 300 kilograms) – protected in the European Union within the Natura 2000 Network. The banks of Slovenian streams are home to the smallest animal on this list – the minute land snail of the Vertigo genus.