A third species of insects in just ten years: a study with the participation of the WSL and University of Bern. Affected are mainly meadows in the country has a strong economy shared environment, but also forests and protected areas.

Disturbing study results from Germany have highlighted the issue of insects, loss in recent years, awareness of, also in Switzerland. Now an international research team with participation of the research Institute for forest, snow and landscape (WSL) and under the coordination of the University of Bern has taken the decline in the number of insects in more detail and more comprehensively under the magnifying glass, the WSL announced on Wednesday.

a wide variety of study areas across the number of insect species declined in the course of only ten years, a little more than a third, report researchers in the journal “Nature”.

the data were Recorded in Germany, the chosen landscapes were, however, comparable with that of various regions in Switzerland, said Markus Fischer of the University of Bern in an interview with the news Agency Keystone-SDA.

rare species

to disappear For their studies, the international research team between 2008 and 2017, and collected over a Million insects in nearly 300 areas in three regions in Germany: Brandenburg, Thuringia and Baden-Württemberg. The areas selected ranged from very natural to agricultural or forestry heavily used Grassland and forests.

Many of the nearly 2700-studied species of insects are on the decline. Especially rare species disappeared in many areas completely.

Previous studies have either concentrated exclusively on the biomass, i.e. the total weight of all the insects, or on individual species or groups of species, said Sebastian Seibold, of the Technical University of Munich (TU münchen) in accordance with the message. “That, in fact, a large part of all the groups of Insects affected, was so far not clear.”

Drastic loss of biomass

the number of found species declined in meadows in the study period by 34 percent. But not only the diversity of species, the total amount of insects shrank, and the dramatic: The insect biomass recorded during the ten years, a loss of two-thirds.

The sharpest decline, the researchers observe on the surfaces, which were in a highly agricultural environment. In particular, schwanden groups of Insects that can overcome any great distance. This suggests a connection with agriculture, what was already suspected.

However, could not yet answer, what is the role of habitat loss, increased use of insecticides or the use of more potent insecticides play, the researchers write in the journal article.

forests

affected Whether and how forests are affected by insects, shrinkage, was unclear. Here, too, the scientists found scientists a decline, and shrank the insect biomass by 41 percent. The number of species declined by 36 percent. Both used for forestry conifer forests, as well as unused forests in protected areas have lost according to the study of insects.

unlike in particular types of meadows were in the forest, the distances. Here is a possible connection with agriculture, however, is still unclear: “Whether it’s the more mobile species from the forest during their propagation more closely with agriculture, or whether the causes are to do with the living conditions in the woods together, we have yet to determine,” said study author Martin Gossner of the WSL.

giant deficit of data in Switzerland

For Switzerland, there is a lack of data on the insects shrinkage. This is a huge deficit, said the fisherman to Keystone SDA. But the data from Germany also for the world of insects Switzerland’t Bode well: In the use of fertilizers and insecticides, there is between the EU and Switzerland, there are no large differences. to close

the gaps in knowledge, he submitted, with colleagues, an application to the Swiss national Fund (SNF) for a National research focus on the causes and consequences of biodiversity loss in Switzerland, according to Fischer. If the decision is positive, a comprehensive long-term study at the earliest next year to start and would then run for a few years. could “But it’s better late than never,” says the researcher.

(oli/sda)

Created: 30.10.2019, 20:22 PM