Nature protection and biodiversity - Drivers and pressures (Slovenia)

The value of the Human Development Index (HDI) in Slovenia has been increasing slowly but steadily since 1992, which means that the quality of life or social welfare has been improving. Biodiversity loss is largely related to this development.

Of all mammals occurring in Slovenia, 36 % are threatened. The largest number of mammal species that are threatened are bats – 22 species of which are threatened especially by habitat loss caused by intensive agriculture and loss of refuge or wintering sites due to inappropriate reconstruction of buildings and the closing of caves. Otter is threatened by habitat loss such as regulation of streams and removal of riparian vegetation, by pollution of streams, by accidents and illegal hunting. Brown bear is threatened by habitat fragmentation caused by construction of new roads. Lynx and wolf are also threatened by illegal hunting. Although the bottlenose dolphin is a highly adaptable species, they are disappearing rapidly from many seas around the globe. Sea pollution, collisions with fast boats and entanglement in fishing nets represent a great threat to the existence of this species.

The main pressures and driving forces are generally well known. The factors frequently act together which makes the causes of biodiversity loss even harder to identify:

1. Loss of habitats, where natural ecosystems are turned into cultivated areas or are built on – expansion of inhabited settlements, changes of land-use categories, traffic infrastructure (TP01,KM10) – exerts great pressure on all land mammals including bats and large carnivores.

2. Non-sustainable use of ecosystems and excessive use of biodiversity. Many species are getting rarer and rarer because of excessive exploitation. Some, including the lynx and wolf, are also threatened by illegal hunting.

3. Climate change is a staggering threat and its consequences are already visible.

4. Invasive alien species, which have spread or been carried from their natural habitats, cause difficulties for the indigenous species in their new surroundings because they compete with them for space and food, spread diseases or are predators. Invasive alien species can change habitats, destroy relationships between organisms in ecosystems, and influence the genetic structure of populations. Over the past decade, the share of invasive species has been increasing. This is most obvious along the big rivers: Sava, Mura, Drava, as well as Kolpa. Till now, higher areas of Slovenia, especially the Alps and the Dinaric Mountains, have very few or no invasive species, however, the noticeable increase of the share of invasive species along the western flank of the Dinaric Mountains is worrying. Among alien plant species in Slovenia, several dozen are invasive, for example, Japanese knotweed (Fallopia japonica), tree of heaven (Ailanthus altissima), Himalayan balsam (Impatiens glandulifera), eastern daisy fleabane (Erigeron annuus) and Canadian goldenrod (Solidago canadensis) (NB09).

5. Pollution of ecosystems because of the use of fertilisers and pesticides in intensive farming, discharge of untreated wastewater, regulation of watercourses, etc. may result in the extinction of species such as the otter and marine mammals. Positive trends are seen in the field of nitrogen balance – surplus of nitrogen, more than 80 kg N/ha at the beginning of the 1990s, started to fall after 2000, and now is between 30 and 50 kg N/ha (KM22).

6. Economic activities, including tourism in areas with sensitive ecosystems. Particularly sensitive is the relationship between the great biodiversity of many areas in Slovenia – one of the key components, together with natural beauty, that attracts tourists to Slovenia – and the environmental pressures of tourism, especially on sensitive habitat types such as karst caves and the breeding areas of species sensitive to disturbance (TU02).