The effects of climate change are particularly evident in the Arctic regions - there apparently continues to continue the warming four times faster than in the global average. This also has serious consequences for the animal world. Researchers around Leana Zoller from the Martin Luther University Halle-Wittenberg in the specialist journal "Nature Ecology & Evolution" report that the populations have drastically reduced in Lapland in Finnish. The working group recorded strong declines, especially for hoverflies and night folds, which specialize in certain flowers when looking for pollen. This would also endanger the continued existence of many plants that rely on the pollinators during the multiplication.
In 2018 and 2019, the researchers around Zoller documented in the small community of Kittilä which insects control which plants and how many pollinators exist. There is a reason why the scientists chose this place in Lapland, about 120 kilometers north of the Arctic Circle, for their study: in the years 1895 to 1900, a forester in Kittilä had systematically recorded pollinators and plants. The environmental researchers have now compared his data with their own results.
"We have found drastic changes in the pollinators' networks," says Zoller, according to a press release from the Helmholtz Center for Environmental Research. The same types of insects and plants were only involved in seven percent of the flower visits today as it was more than 120 years ago. According to Zoller, this is "surprisingly little".
Fewer specialists, more generalists
During their studies, the researchers found strikingly few hoverflies and moths. For this, more bumblebees and flies are now traveling to the region around Kittilä. Zoller and their colleagues could not find out whether their and the pollinator performance of the previous species is approximately the same. So far, there have been no signs that the plants would not be dusted sufficiently. But hoverflies and moths are very specialized and certain plants are presumably more effective than other insects. With its long trays, moths can collect the nectar more easily from tubular flowers.
Currently, other species seem to have taken over the pollen transfer of moths and hoverflies without this leading to a noticeable loss in plant growth. However, if the populations of all pollinating insect species were to decline in the future, the pollinator network could collapse. According to the researchers, studies have shown that further north in the High Arctic, the number of certain flies has already declined rapidly due to global warming.
