The state of biodiversity is not a matter of opinion
Ahead of the vote on the biodiversity initiative, basic insights on the state of biodiversity and habitats in Switzerland are being discussed controversially. Loïc Pellissier counters by holding up the scientific consensus.
I had expected that the referendum campaign on the biodiversity initiative would not be a walk in the park – and prepared myself for a tough but constructive debate on the protection and utilisation of our natural environment. Instead, my colleagues and I ended up in a fundamental debate on the state of biodiversity clarifying the basic facts. What happened?
In July, the Swiss Farmers' Union published a specially commissioned study questioning the Confederation, the cantons and Swiss biodiversity research. The paper attributes a positive overall development to biodiversity over the last 20 years and concludes from this, with media impact, that the biodiversity crisis is being talked up.1
No, biodiversity is not doing well
I conduct my own research into biodiversity and strongly disagree with this view, which does not correspond with the facts. The study focusses one-sidedly on positive aspects in a short period of time and paints a glossed-over picture. The report suggests that everything is fine with biodiversity, no new measures are needed.
But the opposite is the case: I judge the situation of biodiversity in Switzerland to be critical. And I am not alone in this: the study has triggered strong reactions among experts.2 The Swiss Academy of Sciences and the Biodiversity Forum, of which I am Vice President, have publicly disagreed.3 More than 270 researchers have issued a clarifying statement X expressing concern about the state of biodiversity in Switzerland.4, 5
All indicators point to a decline
The reactions illustrate the broad scientific consensus that has grown from a number of studies and data analyses by various experts throughout Switzerland: according to this, the state of biodiversity in Switzerland is indeed worrying.
Despite its existential role, biodiversity is in decline in Switzerland, as highlighted by direct indicators, such as the red list index, trends in species diversity in monitored plots, as well as indirect indicators such as the surface of protected area, and assessment of the cover of valuable habitats for biodiversity.6
The state of Switzerland's biodiversity had severely declined in the last century and trend that has continued in the last two decades. Since 1900, nearly 8000 square kilometers of important semi-natural habitats, such as dry meadows, alluvial zones, and marshes, have disappeared due to ongoing pressure from agriculture and.
“We can reverse the negative trend by restoring more high-quality areas such as wetlands or dry meadows and by better networking and maintenance.”Loïc Pellissier
The decline of high-quality habitats, pollution and more recently climate change are the primary drivers of biodiversity loss in Switzerland: Over than a third of the species and more than half of habitat are endangered.
Lowland areas are in a degraded state, with agricultural land showing a significant deficit in plant and insect species due to intensive use and the application of phytosanitary products such as pesticides. For example, wild bees are severely threatened by pesticides, but also the lack of nesting sites, and the loss of forage plants.
The decline in insects is not only in about species numbers but also in term of the size of populations and biomass, which has cascading effects throughout the food chain such as impacting the populations of lowland insectivorous birds.
Previous measures are not enough
Surfaces of biodiversity-promotion in agricultural landscape have increased since 2011, but the quality of these surface remain too poor to make a significant impact.
Despite some successes, the instruments and measures implemented to date have only been partially realised and are demonstrably insufficient to halt the loss of habitats, biodiversity and genetic diversity.
From a science perspective, we can reverse the negative trend by restoring more high-quality areas such as wetlands and dry meadows, and we need to better connect and maintain these areas. However, the expansion of ecological infrastructure has been stalling for years.
In Switzerland, only 13.4% of the territory is dedicated to biodiversity protection, falling short of the 17% target set for 2020 under the Convention on Biological Diversity (CBD) and the Swiss Biodiversity Strategy.7
Biodiversity concerns us all
We therefore see a great need for swift and decisive action in all areas of life and nature. Responsibility lies with all areas of society. In an international comparison, Switzerland is worse off than many OECD countries and brings up the rear in Europe. Nevertheless, most people in this country believe that biodiversity in Switzerland is in good shape.
This probably has something to do with the fact that the topic has become more important to the public – I read it as a sign that active communication by science is working.
But biodiversity remains an abstract concept and its loss is hidden from most people’s life, which makes it difficult to capture. The current debate suggests that we should expand this dialogue with society.
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