Status: 10:59 am| Reading time: 4 minutes

In the small community of Kittilä in northern Finland, a forester surveyed 120 years ago how often certain insect species approach plants to forage. A research team led by Leana Zoller from the Martin Luther University Halle-Wittenberg and the German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig repeated these measurements and presented them serious changes Celebration.

WORLD: They studied the relationship between plants and pollinators north of the Arctic Circle. What has changed?

Leana Zoller: Only at seven percent of the flower visits we observed involved the same insects and plants today as they did 120 years ago. Nowadays, the plants are visited by significantly fewer hoverflies and moths, and specialized insect species in particular have declined sharply. Specialized insects are often adapted to specific flower shapes through characteristics such as the shape of their proboscis. For example, moths with long proboscises visit different flowers than many types of flies, which only have a very short mouthpiece. These specialists cannot easily switch food sources. They are often the first to be affected by changes such as global warming. In turn, today are more generalized insects like bumblebees and flies in Kittilä on the way.

WORLD: Are these changes cause for concern?

Customs: Specialized insects are usually the more efficient pollinators because they transfer pollen from a specific plant species in the same way. In this way they ensure the continued existence of this plant species. Consequently, increasing generalization could decrease pollination efficiency in the region. On the other hand, the increased number of generalized pollinators could compensate for this.

WORLD: Their investigations showed that the population decline was not greatest in bees, but in flies and moths. Should species protection also focus on these insects?

Customs: In any case. Flies in particular are often ignored in studies and perceived as less attractive than bees. They are extremely important for the pollination network.

WORLD: Assuming the trend you observed continues. What consequences can be expected?

Customs: An ecosystem loses a large part of its biological diversity due to the extinction of specialists. This is problematic.

WORLD: How so?

Customs: The higher the biological diversity, i.e. the biodiversity of a system, the more stable and resilient it is to climate change. Then there is a greater chance that part of the system will successfully adapt to these changes and survive.

WORLD: What influence does man-made climate change have on the changes you observe?

Customs: It is likely that increased temperatures in the region are largely responsible for altering pollination networks.

WORLD: What can we expect in this country?

Customs: The generalization of ecosystems is a global trend that is also observed in temperate climate zones and agricultural regions such as Germany.

WORLD: Concerned about pollination performance?

Customs: At this point in time, the effects are not yet serious because the systems are very adaptable. Plants in Finland are still sufficiently pollinated. However, as the climate change expected that the observed effects will become stronger. If, for example, cold-adapted flies, which do a large part of pollination in Finland, decline, this could have serious consequences.

WORLD: What time period are we talking about?

Customs: That cannot be said in general. But in densely populated and agricultural regions, this will probably happen earlier. These ecosystems are often already ailing.

WORLD: Another question: Which insect are you most like?

Customs: A moth. I also prefer to be out and about in the late evening, when my brain is most active.

To person

Leana Zoller, 30, is doing her doctorate at the Martin Luther University Halle-Wittenberg and the German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig. The ecologist researches the impact of human behavior on ecosystems and biological diversity.

“Aha! Ten minutes of everyday knowledge” is WELT’s knowledge podcast. Every Tuesday and Thursday we answer everyday questions from the field of science. Subscribe to the podcast at Spotify, Apple Podcasts, deezer, Amazon Music or directly via RSS feed.