Because their habitats are being destroyed, severely altered, polluted, separated from each other or disturbed, many of Switzerland’s animal, plant, lichen and fungus species only arise in small populations comprising a few individuals. Small species populations have a greater risk of extinction.
As expert scientific reports, the Red Lists with their staged endangerment categories identify the extent to which previous efforts for the conservation of species diversity have succeeded, and the species and natural habitats for which special protection and promotion measures are required.
To date, one fifth of the around 56,000 known species has been assessed for the Red Lists. 36% of these species are threatened or extinct (see Chart "Species"). This percentage is significantly higher than the average in OECD countries. Every forty-fifth species that was once native to Switzerland is already extinct in this country.
Of the 167 Swiss habitat types, 48% (79 natural and semi-natural habitats) are included in the Red List of natural habitats. Aquatic ecosystems, mires and bogs and agroecosystems are the most threatened (see "Natural habitats").
The high proportion of endangered species and natural habitats provides evidence of the ongoing pressure on species diversity. Therefore, the state is assessed as negative.
The development can be observed only for species groups whose Red List has been revised. This is the case of vascular plants and breeding birds (see Chart "Evolution"). In both cases, the threat level has not changed very much, and has even decreased slightly. In 2016, the RLI (Red List Index) for vascular plants revealed that 82% of vascular plant species are unlikely to become extinct in the near future. This figure was 83% in 2002. The threat status of vascular plants in Switzerland has therefore changed little, and has even fallen slightly. The development is similar for breeding birds, with a higher threat level. The trend is therefore assessed as unsatisfactory.
This evolution is mainly due to the loss and deterioration of habitats (changes in farming practices and their intensity, loss of copses and hedges, forest margins and other small structures, disturbances in the water balance, chemical and physical pollution, the abandonment of farming, destruction of the vegetation cover).
The endangerment categories and criteria defined in accordance with the guidelines of the International Union for Conservation of Nature (IUCN) have been applied for each of the Swiss National Red Lists compiled since 2000.
Red Lists have existed in Switzerland for over 30 years. The classification of species in endangerment categories is based on criteria determining the likelihood of extinction. For example, the smaller and more fragmented an area populated by a particular species and the more rapidly the population declines, the higher its risk of extinction.
Because national field campaigns lasting several years are required for these assessments, the endangerment status of species can only be updated at relatively long intervals (10 to 20 years depending on the species groups). To evaluate the development of the threat level, two Red Lists evaluated on the basis of the same criteria are needed. The Red List Index (RLI) compiled by the UICN summarises all changes that occur when a Red List is revised. The UICN’s Red List Index is calculated based on the method published in Butchart et al. 2007, Bubb et al. 2009.
|Targeted trend||Initial value||Final value||Variation in %||Observed trend||Assessment|
|Growth||(1) 2001, (2) 2002||(1) 2010, (2) 2016||(1) -1.32%, (2) -1.20%||(1) Stabilisation, (2) Stabilisation||unsatisfactory|
|(1) Breeding birds, (2) Vascular plants|