Agroscope, Institute for Plant Production Sciences IPS, 1260 Nyon, Switzerland

Grasshopers need ecological compensation areas

To examine the effectiveness on biodiversity of the direct payments for ecological compensation areas we rely on grasshoppers both as indicators for landscape change and as a small and singing element of biodiversity, however threatened from extinction. To compare the situation before and after the introduction of the ecological compensation areas (ECA) a repeated survey of the grasshoppers was made in the municipality of Schönenberg (canton Zürich) both in 1990 and 2000. In addition we investigated the correlations between grasshoppers and other environmental factors. Most of the ECA in the examined region are legally protected wetland areas (litter meadows cut once a year) offering habitats for rare grasshoppers, which prefer a wet environment. This results in the overall ECA containing more species of grasshoppers than the remaining surfaces, however outside of legally protected areas, the number of grasshopper species increased significantly more on ECA (extensive used meadows and pastures and low intensity meadows) compared to Non-ECA sites. The number of red list species increased in the period between 1990 and 2000 on all ECA more than on Non-ECA. In the examined region the ecological compensation areas have a positive effect on grasshopper diversity.

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