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Return of large wild herbivores to Europe promotes insect diversity – Study – EnviroNews
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Insect species diversity in the European countryside is declining significantly. The return of large ungulates – wild horses, bison and aurochs – to the countryside could help to mitigate this decline.
This is shown by a large-scale study carried out by a team of scientists led by researchers from the Biology Centre of the Czech Academy of Sciences. They monitored five groups of insects at 11 sites where large ungulates graze year-round. The findings were published in the Journal of Applied Ecology.
“We were interested in whether the return of large herbivores could at least partially replace the processes that have been missing from the landscape since the disappearance of the megafauna,” says the study’s author, Martin Konvicka, from the Biology Centre of the Academy of Sciences.
Megafauna, i.e. large herbivores ranging from aurochs and bison to mammoths in prehistoric times, which shaped the European landscape for millennia – have disappeared from most of the continent as a result of human activity. Insects are, however, heavily dependent on the structure of their environment, and as a result of changes to the landscape, they are among the groups of organisms experiencing the most rapid decline.
The research was carried out over a period of 10 years at eleven unique sites established by the European Wildlife organisation. It was this organisation that played a key role in bringing large ungulates back into the wild in Central Europe, thereby creating exceptional conditions for research into their impact on the natural environment. This enabled the researchers to compare pastures where wild herbivores – wild horses, aurochs and bison – were present with surrounding areas where there was no grazing.
It turned out that the number of bee and wasp species and individuals had increased in grazed areas, and the numbers of grasshoppers and locusts had also risen significantly. Among the other groups, which included diurnal and nocturnal butterflies and ants, there was no significant difference in overall species diversity.
“The effect was not the same across all groups, but the important thing is that we did not observe any negative impacts of large animals on any of them,” says entomologist, Jan Walter.
Close collaboration with scientists has been a key part of the project, from the preparation of the first large herbivore reserve in 2013, through its opening in 2015, to the gradual establishment of additional large herbivore reserves – of which a total of 18 have now been created in Central Europe thanks to the European Wildlife conservation organisation.
“We are delighted that the findings of a large-scale scientific study have confirmed that large ungulates are a key part of Europe’s natural environment. Thanks to their return, biodiversity is being restored very quickly. The numbers of individuals belonging to endangered species, which had been on the brink of extinction locally, began to rise very rapidly by hundreds and even thousands of per cent,” said Dalibor Dostal, the director of European Wildlife.
A key finding of the study is that the return of large ungulates to the landscape is fundamentally altering the species composition of the insect fauna. The species that are increasing in number are primarily those that: are smaller and less mobile, have more specialised environmental requirements, feed on low-growing herbs, and are able to survive in habitats regularly disturbed by grazing.
“Large herbivores create a diverse mosaic of habitats, ranging from grazed areas to disturbed soil. And it is precisely this diversity that is crucial for many species of insects,” explains Konvicka.
Most of today’s insect species evolved at a time when the European landscape was inhabited by abundant megafauna. Once it had been depleted by human activity, its effects were replaced by traditional farming practices, which involved the constant presence of cattle, horses and other animals in the countryside. However, modern intensive farming and forestry have eliminated these conditions.
According to the authors of the study, the return of large herbivores to the landscape mimics the natural disturbance of the environment previously caused by large animals. It thus restores missing ecological processes and can mitigate the negative impacts of intensive farming.
The authors also point out that this approach is not a one-size-fits-all solution. Conversely, some insect species may be suppressed, such as those associated with tall grass vegetation or areas that are not greatly disturbed.
“It is important to maintain diversity in the landscape – that is, a combination of grazed and ungrazed areas. Provided the areas are large enough and home to large ungulates, this would be ensured by the animals’ own activity, combined with the presence of predators,” adds Konvicka.
The return of wild herbivores therefore represents a promising tool for the conservation of insects and other organisms, for the restoration of the landscape’s ecological functions, and also offers an alternative to the costly management of certain protected areas.
“Large herbivores are not just a symbol of the wilderness. They are key architects of the landscape that help to sustain life in all its diversity,” concludes Konvicka.
