16.06.2022 | Majken Grimm | News WSL
Where do the five main species of wood ants in Switzerland potentially occur? New maps provide information.
Wood ants, known for their ant hills, belong to the key species in the forest ecosystem. They spread seeds, keep pests at bay and improve soil quality. This is why they were the first insects to be placed under protection in Switzerland in 1966. In the framework of the fourth National Forest Inventory (NFI), the occurrence of wood ants was recorded on more than 6000 forest plots.
Based on these data, on cantonal ant inventories and on occasional sightings, WSL scientists modelled the potential distribution of the red wood ant (Formica rufa) and of the four other main species of this group present in Switzerland (Formica polyctena, Formica paralugubris, Formica lugubris and Formica aquilonia). The resulting distribution maps are available on the IFN website. They show where environmental conditions are suitable for wood ants, distinguishing areas where each species is found with great certainty, where an occurrence is possible but not certain, and where the species is unlikely to be present.
In general, mountain forests with a high proportion of conifers are ideal habitats for the five species. In addition, forests should not be too dense for light to reach the ground, and ground vegetation should not be too disturbed.
The maps contribute to a better protection of wood ants, by targeting the places where they are already present. Where the presence of ants is possible, but not confirmed, it would be desirable to carry out further surveys. Wood ants might even be released in these areas. Distribution maps are intended for conservation specialists, forest owners and people interested in ants.
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