Swiss Federal Research Station for Agroecology and Agriculture, Zurich-Reckenholz

Methods for the rapid assessment of ecological compensation areas

The quality of ecological compensation areas is decisive for the success of the measures of ecological compensation. Currently, there is no method that allows the rapid assessment of the biodiversity of a large number of ecological areas. Therefore, the FAL carried out methodical investigations in order to determine the suitability of various animal and plant species as indicators as well as examining the meaningfulness of the vegetation structure. Between 1997 and 2000, we determined the species diversity of spiders, bugs, and flowering plants for the two types of ecological compensation areas, meadows and wildflower strips. The results confirm that under the most favourable conditions, such ecological compensation areas can have a very high biodiversity. In Randen (in the canton of Schaffhausen), we examined meadows that had been cultivated in the same manner for several years. Here, the number of seed plant species correlated with the number of spider and bug species. In other meadows and wildflower strips, however, the number of seed plant species alone did not allow for any conclusions on the diversity of the two aforementioned animal species. According to the type of ecological compensation area and the indicator group, the vegetation structure accounted for between 40 to 70% of the variations in species diversity. In particular thin and staged stocks seem to be favourable for a large biodiversity. Data on vegetation structure is easier to assess than data on the number of species. Therefore, such data is a good basis for the efficient assessment of the quality of ecological compensation areas.

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