Successful sampling strategy

With the supplementary sampling of Melitaea diamina, the 2022 field season was successfully completed. The collected samples of the five species are distributed – according to their habitats – over the whole of Switzerland and all biogeographical regions. The sampling includes more than 1200 individuals from 158 populations.

Populations sampled and biogeographic regions of Switzerland

The specifically developed sampling strategy (proportional stratified random sampling) has proven successful: the climatic niche, i.e. the range of temperature and precipitation suitable or expected for a species, is well covered for all species.

Distribution of the known (grey) vs. sampled (red) populations of all five species in the Swiss climate niche.
(c) Oliver Reutimann, ETH Zürich

In addition, areas of varying size, quality, and connectivity were selected using the random sampling strategy.

Example of Eriophorum vaginatum: both large, protected upland bogs and small or isolated patches were considered in the study.
(c) images: Martin C. Fischer, ETH Zurich