Mixed results on the development of biotopes of national importance

A new report by the Swiss Federal Research Institute WSL shows the most important developments in biotopes of national importance - they are both positive and negative. There is still a great need for action, particularly in wet habitats such as floodplains, fens and raised bogs, to ensure that these valuable biotopes are preserved in the long term.

• The Biotopes of national importance are highly valuable for biodiversity in Switzerland. In the programme "Monitoring the effectiveness of habitat conservation in Switzerland WBS" WSL analyses how these biotopes are changing on behalf of the FOEN.
• A new WSL report shows that there have been both positive and negative developments in these biotopes since the first survey (2011-2017)
• Further efforts are needed to preserve these biotopes in the long term.

A WSL report published in July 2025 shows that there have been both positive and negative developments in all five biotopes studied – dry meadows and pastures, raised bogs and fens, floodplains and amphibian breeding sites – since the first status report in 2019. "The positive developments indicate that the nature conservation measures taken by the cantons and other stakeholders are having an impact," says Ariel Bergamini, who heads the programme at WSL. However, there is still work to be done, because the wet habitats in Switzerland in particular are in a poor state.

Dry meadows and pastures are species-rich habitats that are normally very low in nutrients. Results show that nutrients have decreased throughout Switzerland as indicated by the vegetation, particularly in the more nutrient-rich meadows, while at the same time the proportion of typical and endangered plant species has increased. The area of dry meadows and pastures has also increased. Besides these positive developments from a nature conservation perspective, there are also negative ones: There has been a slight increase in non-native, invasive species and woody plants that compete with typical species. Roads and paths have also increased slightly.

Raised bogs and fens are nutrient-poor, wet habitats that are home to highly specialised species. Raised bogs are continuing to dry out, the proportion of habitat specialists is declining and the area of raised bogs has even shrunk by 6.5 per cent , which corresponds to almost 100 football pitches. Nevertheless, the vegetation shows no further increase in nutrients compared to the last survey. There was also no increase in non-native plants and no increase in infrastructure such as roads or buildings.

The majority of floodplains, particularly along rivers and in river deltas, are developing negatively and the condition of these habitats is poor. Invasive non-native plants have increased and the area of hardwood floodplain forests has decreased. Floodplain specialist plants have also declined, and natural disturbances caused by flooding and the deposition of sand and gravel have decreased as indicated by the vegetation. There is a great need for action here.

The surveys carried out by info fauna karch in the amphibian breeding sites showed no further decline in amphibians. This is likely a consequence of nature conservation measures taken, such as the construction of new ponds. However, the number of colonised sites is still significantly lower than in the 1980s, especially for highly endangered amphibian species such as the Common midwife toad and the Yellow-bellied toad. In order to reverse the trend, it is important that the measures are maintained and strengthened, according to the report.

The report concludes that additional efforts are needed to preserve biotopes of national importance in the long term, particularly in view of climate change. For example, in the raised bogs and fens: "Further restoration measures are key to re-establishing the natural water balance of fens and bogs. More consideration must also be given to their hydrological catchment area in order to ensure the water supply of these wet habitats," says Bergamini.

With the programme “Monitoring the Effectiveness of Habitat Conservation in Switzerland WBS”, Switzerland is taking on a pioneering role in biodiversity monitoring, as national programmes that examine the effectiveness of protected areas with regard to their success are rare worldwide. The impact monitoring complements the two other major Swiss federal monitoring programmes, the Biodiversity Monitoring Switzerland BDM of the Federal Office for the Environment FOEN and the "Species and Habitats Agriculture ALL-EMA" programme of Agroscope.

Monitoring the Effectiveness of Habitat Conservation in Switzerland WBS

To protect vulnerable habitats and their biodiversity, Switzerland designated about 7000 sites of national importance. These sites are legally protected and include fens and raised bogs, dry grasslands, and flood plain habitats as well as amphibian breeding sites. In 2011, the Federal Office for the Environment (FOEN) and the WSL Swiss Federal Research Institute launched the joint project "Monitoring the effectiveness of habitat conservation in Switzerland WBS" to observe developments and changes in these sites - with aerial photographs, vegetation surveys and amphibian counts. Further information on the monitoring programme: https://biotopschutz.wsl.ch/en/

Additional videos on the three modules (Remote Sensing, Vegetation and Amphibians) can be found here.